Page 1 of 9 123 ... LastLast
Results 1 to 15 of 132

Thread: Two Propulsions of Electricity and Compressed-air for a Hybrid Car

  1. #1
    Join Date
    Aug 2011
    Location
    Karaj
    Posts
    91

    Two Propulsions of Electricity and Compressed-air for a Hybrid Car

    Hello everybody. I've worked on a plan of a hybrid car for about a year. My intention was to help the environment, in particular the weather of Iran where we suffer from its pollution. I started a review on the existing possibilities and I found out the electric vehicles are interesting options. So I focused on removing their flaws and I reached to the present document. I hope to improve it by the help of experts. Also I like a company or person would determine to build it; because I cannot by myself. I'm just a man of theory without any equipments. However, I will keep contacting to active companies about my plan with the hope of realizing it someday. If this plan would gain attention from the people who care about the environment and future of the planet, that would be a contribution of mine to the world.
    You can download my plan, a 60-pages PDF file from one of these links:

    On developing a powertrain in a hybrid car with electricity and compressed-air propulsions (zipped)
    On developing a powertrain in a hybrid car with electricity and compressed-air propulsions

    Cheers,
    MM

    P.S: I'm glad I found here after some web surfing. It sounds there are experts in here and I hope they would guide me how to proceed. Please note English is not my first language and if this category is not fit, I ask moderators to move this thread. Thanks already.

  2. #2
    Join Date
    Jun 2010
    Posts
    82
    Welcome Mohammed. I have read your paper, and would like to venture a few thoughts. I am not an expert. Like most people here, I am an enthusiast, but not a trained professional in the industry. However, I have a good technical understanding, so I hope that I can offer some constructive criticism.

    I get the impression that you have written that paper in the style of a thesis. Do you have any intention of eventually submitting it for a degree - an honours or masters? If so, I fear that it may not be well received. It seems to be a collection of your thoughts on energy scavenging and efficiency, and you seem to have given the subject a lot of thought. However, there is no real theoretical support for any of your ideas.

    The compressed air propulsion is a neat idea, but it is an equivalent system to the electric storage system. The main benefit of both systems is their ability to recover energy from the movement of the vehicle, when decelerating, and to use it to propel the car when it accelerates again. The limit on this process is the kinetic energy of the car - you cannot recover more kinetic energy from deceleration than the car has gained during acceleration. Therefore, an extra energy recovery system will not increase the amount of energy that can be recovered.

    In addition, as you mention, the weakness of electric vehicles is currently their short range. This is due to the relatively low energy storage density of batteries, compared with combustible fuels. The compressed air drive offers no advantage over electric drive, unless the pressurised air tanks can store more energy per unit weight and volume than the equivalent batteries could. The calculation is fairly simple - usable energy is determined by pressure times change in volume. Therefore, the energy stored in each tank will be a product of the pressure and the volume of the tank. If this number is lower per unit weight than the energy capacity of a battery, the compressed air offers no performance advantage. This is the sort of theoretical calculation that you require to support your ideas.

    Similarly, you suggest using passenger power to generate both electricity and compressed air. There is redundancy here too, as it may be assumed that any one passenger will only generate a limited amount of power, and that will be unchanged by having the option of generating power as compressed air, or as electricity. Having both options will again not increase the amount of energy made available.

    A further problem is that a person cannot generate much energy. A strong cyclist will generate 200-300 watts continuously. A car requires several tens of kilowatts to reach legal speeds, and several kilowatts to maintain speed. A good cyclist can cruise at 30-35km/h, but that is propelling only the cyclist and the bicycle. A car, even with vastly superior aerodynamic properties to a bicycle, will have much higher losses from heavier bearings, larger, higher resistance tyres, and the hugely higher weight of the vehicle. Thus the contribution of exercising passengers would be insignificant. In terms of marketability, if a passenger wanted to exercise, they may well ride a bicycle, rather than using a car in the first place. Similarly, bus passengers have paid their fare, and I do not know many who would be willing to pedal the bus themselves.

    In a more general sense, you need to give more thought to the amounts of energy involved. You cite examples, such as dynamo torches, which require 30 seconds of charging to provide 5 minutes of light. The amount of energy required by a car is enormously higher, and the contribution of a passenger winding such a dynamo for 5 minutes is insignificant, even compared with the amount of energy generated by running or pedalling hard. Similarly, energy scavenging devices, like linear electric motors and piezo materials are unlikely to generate a noticeable amount of power.

    It is also worth noting that energy that is scavenged does not always come for free. Having an external turbine to recover energy from airflow will increase the aerodynamic drag of the vehicle, increasing the energy it needs to propel it, making it self-defeating. Likewise, having linear electric motors to recover vibrational energy may be self defeating, if the weight of the motors is high and the amount of energy recovered is small. The one device which I think has promise is energy recovery from the suspension. Currently, shock absorbers exist to dissipate the energy that the suspension absorbs over bumps. Springs and shock absorbers could both be modified to act as linear electric motors, with the dual benefits of energy recovery, and electrical feedback being used to adjust the damping properties of the suspension, to benefit handling. Because the force experienced and the distance moved by the suspension are both relatively large, there are more significant amounts of energy to be recovered by this method.

    Finally, you suggest that introducing solar panes into the body panels of the vehicle is likely to reduce the safety of the vehicle. The skin panels of a car are not load bearing. The strength and safety are provided by the structure under the skin, so removing the panels and replacing them with solar panels will probably not make any meaningful difference to the strength or safety of the car.

    I hope that none of this is too discouraging. As I said, I am not an expert in the field, so I may be wrong. However, you require some theoretical support for your ideas to demonstrate that they have benefits compared with currently used technologies. Meaningful, supported estimates of the power that may be generated by each method, and how much it is likely to weigh and cost, would improve your ideas considerably.

    I hope that this is of some help.

  3. #3
    Join Date
    Aug 2011
    Location
    Karaj
    Posts
    91
    Thank you so much for the reply MilesR. This plan needs constructive criticism as you mentioned to become satisfying more and more.
    I get the impression that you have written that paper in the style of a thesis. Do you have any intention of eventually submitting it for a degree - an honours or masters? If so, I fear that it may not be well received. It seems to be a collection of your thoughts on energy scavenging and efficiency, and you seem to have given the subject a lot of thought. However, there is no real theoretical support for any of your ideas.
    I am an enthusiast too and I've presented some of my ideas in that paper to help the environment, because I'm worried about this planet. I don't want any academic thing, I want somebody with required capabilities would decide to realize my plan. It is just a description and it lacks the mathematical calculations to support it. The related calculations need to be done by advanced softwares after numerous simulations which I am not able to do them. I think if a company would conclude to make such a car, it needs to like the very plan at first, then such calculations in the spirit of optimizing the methods would naturally be essential before going from the paper to the real world. Also, I didn't observe such detailed reviews in some of the patents. However, I prefer doing experimental tests, because a car experiences much various conditions in reality and predicting all of them in theory won't be completely practical.
    The compressed air propulsion is a neat idea, but it is an equivalent system to the electric storage system. The main benefit of both systems is their ability to recover energy from the movement of the vehicle, when decelerating, and to use it to propel the car when it accelerates again.
    Both compressed-air and electric propulsion systems have advantages and disadvantages compared to each other and compared to internal combustion engine vehicles. For example look at these links:
    Compressed air car - Wikipedia, the free encyclopedia
    Compressed-air vehicle - Wikipedia, the free encyclopedia
    Electric car - Wikipedia, the free encyclopedia
    The limit on this process is the kinetic energy of the car - you cannot recover more kinetic energy from deceleration than the car has gained during acceleration.
    Surely, that would be against the laws of physics.
    Therefore, an extra energy recovery system will not increase the amount of energy that can be recovered.
    You're right, but we should try to make the amount of energy recovery higher, as much as possible. For example, in the Ref. [101] of my paper, I've suggested to use hydraulic hybrid system:
    The benefits of using a hydraulic hybrid system, according to EPA claims, are a 60%-70% increase in fuel economy (based on lab tests), a 40% reduction in CO2 emissions, and a lower "hybrid penalty" costwise, which can be recovered in as little as three years due to fuel savings (1,000 gallons of diesel/year) and reduction in brake maintenance costs.
    Due to this post:
    EPA unveils hydraulic hybrid UPS delivery truck
    I agree this system would be less efficient in a vehicle that is smaller than a truck and stops less frequently than a delivery truck, but we can combine it to other available methods. The regenerative brakes, start-stop mechanism, the flywheel (see Ref. [17]), and three approaches giving contribution to provide electricity, which are absent in conventional electric vehicles, i.e., solar cells, bio-force and physical effects. All these items are needed to get that increase in fuel economy to higher percentages.
    BTW, I have some raw ideas to apply the hydraulic hybrid in small cars much more effectively, but that needs some knowledge from chemistry, not physics or engineering, I might deal with them in the future …
    In addition, as you mention, the weakness of electric vehicles is currently their short range. This is due to the relatively low energy storage density of batteries, compared with combustible fuels. The compressed air drive offers no advantage over electric drive, unless the pressurised air tanks can store more energy per unit weight and volume than the equivalent batteries could. The calculation is fairly simple - usable energy is determined by pressure times change in volume. Therefore, the energy stored in each tank will be a product of the pressure and the volume of the tank. If this number is lower per unit weight than the energy capacity of a battery, the compressed air offers no performance advantage. This is the sort of theoretical calculation that you require to support your ideas.
    As you can see in the above cited links, there are several advantages for the compressed-air propulsion over the electric propulsion, that's the same about the disadvantages. One of them I like is that you can fill up a compressed-air tank so quickly, say 2 minutes, no battery can be charged so fast.
    Anyway, as it is observed in the paper, my strategy to cope with the short mileage of the electric vehicles, is to create electricity while driving. Therefore, the main role is played by supercapacitors to quickly receive the harvested electricity and release it rather fast. I estimate the overall devoted electricity to the battery packs would be 20% or even less. The stored energy for this car in the form of electricity or compressed-air is not static, it's a dynamic process that is being provided and consumed continuously; before, during, and after driving the car.
    Similarly, you suggest using passenger power to generate both electricity and compressed air. There is redundancy here too, as it may be assumed that any one passenger will only generate a limited amount of power, and that will be unchanged by having the option of generating power as compressed air, or as electricity. Having both options will again not increase the amount of energy made available.
    I know the bio-force is limited, but it can help. This desire to relax the body and relying on machines to do the things for us has caused bad ramifications for the environment. Imagine what would happen if all the Chinese or Indian families decide to use personal vehicles like the American families.
    My proposal is doing most of non-propulsion tasks by the bio-force, definitely the ventilation for the passenger and components, plus the recreational affairs inside the car. If one resembles the sliding magnets for this car to the blood flow or circulatory system, the bio-force section makes it a living being, a horse that needs some massage to ride. The passengers would have this confidence that this car is not useless when they run out of fuel and there is no other car to help, unlike the ICE cars.
    If you really like to get rid of the oil addiction for the mankind, please be optimistic about this. Bio-force is a part of what we need.

  4. #4
    Join Date
    Aug 2011
    Location
    Karaj
    Posts
    91
    A further problem is that a person cannot generate much energy. A strong cyclist will generate 200-300 watts continuously. A car requires several tens of kilowatts to reach legal speeds, and several kilowatts to maintain speed. A good cyclist can cruise at 30-35km/h, but that is propelling only the cyclist and the bicycle. A car, even with vastly superior aerodynamic properties to a bicycle, will have much higher losses from heavier bearings, larger, higher resistance tyres, and the hugely higher weight of the vehicle. Thus the contribution of exercising passengers would be insignificant. In terms of marketability, if a passenger wanted to exercise, they may well ride a bicycle, rather than using a car in the first place. Similarly, bus passengers have paid their fare, and I do not know many who would be willing to pedal the bus themselves.
    Please notice I never suggested to totally rely on the passengers' power to propel this car, that's obviously impossible. Although, I think their contribution is not insignificant. In an ideal picture, people will be active in these cars, you know the sport is good for health. People would tend to not ride alone, getting in another buddy might provide some electricity, a cool news for the hitchhikers! For comparison, according to this report: VERIDIAN | First plug in hybrid solar electric vehicle in Canada
    One number of 240-watt sunroof can contribute enough energy to allow the vehicle to travel up to an additional 14 km in electric-only mode on a sunny, summer day. That's comparable with the amounts of electricity that normal people could produce by pedaling or handling time to time. Consider a long trip and the ones who like to help the car to propel because they're bored with listening to the music or watching around or anything that is a passive action. The children and teenagers might do bio-force for fun, and adults might do it to release their stress, e.g., see figures 25 or 28 in my paper. I think this possibility will help those passengers who are motionless in a traffic too. FYI, sitting for a long time could severely damage your health:
    Is Sitting a Lethal Activity? - NYTimes.com
    The Most Dangerous Thing Youll Do All Day
    Can sitting too much kill you? | Guest Blog, Scientific American Blog Network
    Discovery Health
    Why sitting all day is slowly killing you - Health - Men's health - msnbc.com
    What is wrong with rotating a handle for 40 times to cause your LCD keep showing you a movie from a DVD player for a further 5 minutes? Of course that shouldn't be an obligation, one could count on the solar cells or other methods of gaining the electricity in this car, instead of bothering himself to produce the electricity to watch a film, but that should remain as an option if one decides to reduce the pressure on the batteries and supercapacitors to let them only be devoted to the propulsion.
    About the bus, I guess that would be better to propel them with the help of compressed-air tanks than huge lithium-ion battery packs, if those are supposed to be made fossil fuel free. You're right about a public bus, but due to my experiences bus passengers belonging to a group would like to make fun and joy out of everything and would cooperate with the driver to have public experience from their trip. Pedaling for the numerous small compressed-air tanks or batteries by one passenger won't be a big help for a large bus, but I think doing it by a major part or all of the interested passengers must remain as an option (not obligation). Anyway, my focus in this paper is on the small personal cars, not bikes or trucks or buses.
    Similarly, energy scavenging devices, like linear electric motors and piezo materials are unlikely to generate a noticeable amount of power.
    There is no term on "linear electric motors" in my paper. I guess you mean the linear induction. Indeed that's the core of my plan and as I've declared:
    This approach is a promising and most innovating technological approach. It yields a considerable amount of electricity while driving the car due to physical properties of components. It is not as trivial to charge the grid, as weak as charge the solar cells, and as difficult as charge using the bio-force with passenger muscles. In the most optimistic states, this approach might delete the need to other approaches.
    Don't consider it unlikely, this is the masterpiece of the plan. If there is any specific question about this, I'm ready to answer it. The calculations for this part are very complex, but surprisingly the required experiments to show the efficiency of this approach might be rather simple, however those cost much and I cannot do them for the present time.
    About the piezoelectric materials, well that's great too. Although, I don't insist on it. I just wanted to generalize and extrapolate the present applications of such an effect into an electric car. To clarify, look at this paragraph: Piezoelectricity - Wikipedia, the free encyclopedia
    High voltage and power sources …
    A similar idea is being researched by DARPA in the United States in a project called Energy Harvesting, which includes an attempt to power battlefield equipment by piezoelectric generators embedded in soldiers' boots. However, these energy harvesting sources by association have an impact on the body. DARPA's effort to harness 1-2 watts from continuous shoe impact while walking were abandoned due to the impracticality and the discomfort from the additional energy expended by a person wearing the shoes. Other energy harvesting ideas include harvesting the energy from human movements in train stations or other public places[17][18] and converting a dance floor to generate electricity.[19] Vibrations from industrial machinery can also be harvested by piezoelectric materials to charge batteries for backup supplies or to power low power microprocessors and wireless radios.[20]

    Or this one: Piezoelectricity - Wikipedia, the free encyclopedia
    Piezoelectric motors …
    Rectangular four-quadrant motors with high power density (2.5 watt/cm3) and speed ranging from 10 nm/s to 800 mm/s.

    Look at the involved numbers and dimensions of the devices in relation to this effect. Hence, to avoid wasting time on considering making power out of passengers' butts, that would be greater to focus on intense strains among the chassis and body in addition to wheels and the ground to use piezoelectric materials in such components to gain considerable amounts of electricity for ventilation, recreation and propulsion affairs. I'm telling as far as I know, there is a huge strain between the chassis and body of any imaginable car, so why don't we use such a possibility as an advantage?
    Last edited by mansouryar; 10-20-2011 at 03:21 PM.

  5. #5
    Join Date
    Aug 2011
    Location
    Karaj
    Posts
    91
    Having an external turbine to recover energy from airflow will increase the aerodynamic drag of the vehicle, increasing the energy it needs to propel it, making it self-defeating.
    I suggested to install some tiny vertical axis wind turbines (VAWTs) at some channels of the rear diffuser. I thought it might work, however I have the least insist on this special item. You can simply ignore it, I don't defend it so much.
    Likewise, having linear electric motors to recover vibrational energy may be self defeating, if the weight of the motors is high and the amount of energy recovered is small.
    I repeat, there is no such a thing as linear electric motors in my paper, you misunderstood it. You're talking about "the electricity caused by Faraday's law of induction, after sliding a rare-earth magnet inside a solenoid". I developed this idea inspired by the linear particle accelerator:
    [ame="http://en.wikipedia.org/wiki/Particle_accelerator"]Particle accelerator - Wikipedia, the free encyclopedia[/ame]

    [ame="http://en.wikipedia.org/wiki/Linear_particle_accelerator"]Linear particle accelerator - Wikipedia, the free encyclopedia[/ame]

    This is the heart of my plan, if it functions well, you can forget almost all other items; otherwise my plan won't have much innovation.
    The one device which I think has promise is energy recovery from the suspension. Currently, shock absorbers exist to dissipate the energy that the suspension absorbs over bumps. Springs and shock absorbers could both be modified to act as linear electric motors, with the dual benefits of energy recovery, and electrical feedback being used to adjust the damping properties of the suspension, to benefit handling. Because the force experienced and the distance moved by the suspension are both relatively large, there are more significant amounts of energy to be recovered by this method.
    Hopefully you liked one of my ideas! Well, I just paid attention to an article about two MIT students:
    Invention Awards: Power From Shock Absorbers | Popular Science
    … They began by creating a simple hydraulic system, in which the shock absorber's piston pumps fluid to drive a hydraulic motor and a miniature electric-motor generator. The team's first prototype generated a total of 800 watts of continuous power with four shocks, and up to five kilowatts — about seven times as much as a typical car alternator produces — over nasty off-road terrain. They estimate that their next version could double the generating capacity, boosting fuel mileage on paved roads by 2 to 5 percent in commercial trucks and 6 percent in military vehicles, which when fully armored can slurp diesel at a dispiriting four to eight miles per gallon. Hybrids, which can store GenShock electricity in their batteries, would gain the most — up to 10 percent. …
    I liked the news and I asked why shouldn't we apply this in an electric car? Also I generalized this idea to spokes on the tweels. This is very cool and it could help to earn electricity for the cars. I see this promising in the future.
    Finally, you suggest that introducing solar panes into the body panels of the vehicle is likely to reduce the safety of the vehicle. The skin panels of a car are not load bearing. The strength and safety are provided by the structure under the skin, so removing the panels and replacing them with solar panels will probably not make any meaningful difference to the strength or safety of the car.
    This is so nice. I just mentioned some solutions to keep the skin robust as well.
    I hope that none of this is too discouraging. As I said, I am not an expert in the field, so I may be wrong. However, you require some theoretical support for your ideas to demonstrate that they have benefits compared with currently used technologies. Meaningful, supported estimates of the power that may be generated by each method, and how much it is likely to weigh and cost, would improve your ideas considerably.
    Alright, thanks for your comments. This plan needs much furbishing to become a proper plan. I can proceed the theoretical part, but I can't do the same about the practical part. I think even a small car company can't afford the involved patents. Only major auto makers could do this. I think this car is very better than Toyota Prius, Chevrolet Volt, or Nissan Leaf.
    BTW, you can have my paper from this new address as well:
    On Developing a Powertrain in a Hybrid Car with Electricity and Compressed-Air Propulsions
    One more thing, I found here interesting, but if you think here is not suitable for such discussions, I'd be thankful if you'd address me another forum to explain my ideas in there.

  6. #6
    Join Date
    Jun 2010
    Posts
    82
    This forum is for discussing the technical aspects of car design, so it is the right place for this type of discussion. Also, these ideas are worth discussing, because this type of discussion can be a great source of inspiration. It can lead to ideas being improved, or even to the creation of entirely new ideas, so it is certainly worthwhile.

    Certainly computer simulation and prototype testing are difficult things to do without the support of an organisation, like a manufacturer or university, however there are some simple calculations that can be included. For example, the energy required to compress air is a simple function of the pressure and the volume. Likewise, you may be able to estimate the percentage of this energy that can be recovered, based upon the estimated efficiency of whatever design of compressed air motor you select. This would allow a rough comparison with a battery or supercapacitor, and would help to support the argument. Likewise, you might include the estimates of power generated from suspension energy recovery, simply by quoting the numbers suggested by the MIT students who proposed it.

    A linear electric motor can have a couple of configurations. One configuration is equivalent to unrolling a rotating electric motor, while another uses rack and pinion gears to adapt rotary motion to translational motion. In either case, they can be applied as generators. They are equivalent to attaching a shaft to the magnet in one of your linear induction devices, so that it can be driven by an external input, instead of inertia alone. I generalised the concept of the linear induction generator to that of the linear electric motor, and that is why I referred to it as a linear electric motor. Sorry about that. It was not due to misunderstanding, just a theoretical generalisation.

    I think the inclusion of piezo materials into the structure of the car is a good idea, as the generation of electricity from deformations in a structure would also help to damp the deformations and resonances in the structure. The vibrational resonances of a car body can lead to a booming effect over rough roads, so reducing the energy of these vibrations by harvesting them as electricity could also make a car quieter. This would be an easy thing to sell, particularly if the piezo materials are cheap and easy to install during production. A downside of this approach is that manufacturers put considerable effort into increasing the rigidity of their cars. Smaller deformations mean that there is less energy to recover from the structure, so later generations of cars are likely to be progressively less suited to this type of energy harvesting. Some theoretical support for this idea could be gained by estimating the deformations experienced by a car body, and estimating the amount of energy that a piezo material could recover from this deformation. Likewise, the linear vibrational inductors are likely to generate little energy, if the manufacturers succeed in providing a smooth ride. This is why this type of generation is probably best concentrated in the suspension system.

    One area where I would like to see piezo materials applied is in a car's springs. The springs experience considerable displacements, and have a large surface area, so they could support a large amount of piezo material, and the piezo energy generation would introduce a self-damping effect into the spring. Likewise I would like to see a linear electric motor used in place of a shock absorber, as it would allow direct electricity generation, as well as instantaneous electric adjustment of the suspension properties. However, I am aware that a sufficiently light linear electric motor is unlikely to generate sufficient force to work well in this application, and that this is why the MIT crew used hydraulics instead.

    I agree entirely that some physical activity is preferable to idleness, and that there would be some people who would be willing to participate in such activity. I also agree that such devices can extend the range of an electric vehicle. My argument here is more one of practicality. The energy contribution from exercise will necessarily be small, and as you point out, may increase range by up to 14km per person contributing. This is a small contribution to the range, and will not, on its own, extend the range of an electric car (100-200km, or so?) to be competitive with a hydrocarbon-powered car. That is not to say that it is not a worthwhile contribution, though. However, 240W is equivalent to a strong cyclist maintaining a rather fast cruise, or a runner maintaining a fast jog. The body heat generated by this activity is likely to require a similar amount of energy to be dedicated to air conditioning to cool the passenger. Also, to be equivalent to the 240W of the solar panel, the contributor would have to maintain this output continuously, for a day, as the solar panel would. That is a big ask.

    In addition, another practical consideration is that seat belts are compulsory in much of the world, and I have trouble imagining how safety can be engineered into a treadmill, particularly with the runner's head protruding from the sunroof. A set of cycling pedals in front of each seat might be preferable. In fact, I would be interested to see that idea implemented in an office - pedalling to power your computer would improve fitness, reduce thromboses, and perhaps reduce power use. On the other hand, encouraging people to wear shorts and t-shirts, rather than business suits, would reduce the air conditioning needed to maintain comfort in an office, and I have not seen anyone introduce a measure even this simple, so my hopes for pedal-powered computing are not likely to be fulfilled any time soon.

    I realise that the compressed air propulsion would be much faster to fill than a battery. It would also have advantages such as reduced reliance on relatively rare and toxic materials, lower production cost, and maintenance that could be performed by a mechanic, rather than an electrician or chemist. However, such advantages are immaterial, if the system ends up increasing the weight of the vehicle, without appreciably improving the range. This is why I would be interested to see an estimate of the possible energy density of such a system.

    Finally, you base your proposals around large and heavy vehicles, which are not a particularly good proposition from an environmental point of view. You also suggest that it should have a bull bar, front and rear, for safety. Safety is not improved by such devices, as they can interfere with the normal operation of crumple zones. They also significantly increase weight and aerodynamic drag, reducing efficiency. Finally, you propose the addition of linear induction generators, which, if the car rides smoothly, will generate limited power, and will increase weight. This will all add up to a very heavy vehicle, with poor airflow characteristics. The contributions from piezo, induction, exercise and solar panels will all be diminished by the increased energy demands of a vehicle of this nature.

    Personally, I would be interested to see some of your energy scavenging techniques applied to an existing well-designed car. A Honda Insight series 1 would make a great project vehicle, as you would start with a well designed electric hybrid vehicle. The electrical system could be modified to use more supercapacitors, in place of batteries, the petrol engine could be replaced with your compressed air drive, the suspension and structure could be modified with your energy scavenging techniques, and there would probably even be space in the passenger seat for a set of pedals. It would probably still need the backing of an organisation, to cover the engineering and manufacturing costs, but a small, simple car, designed for both electric and mechanical drive, and with room for modification, would be a good place to start.

    By the way, if your have any chemistry related problems, feel free to explain them. There are several people here who are studying various sciences, so you may find someone who can help.

  7. #7
    Join Date
    Aug 2011
    Location
    Karaj
    Posts
    91
    Likewise, you may be able to estimate the percentage of this energy that can be recovered, based upon the estimated efficiency of whatever design of compressed air motor you select. This would allow a rough comparison with a battery or supercapacitor, and would help to support the argument. Likewise, you might include the estimates of power generated from suspension energy recovery, simply by quoting the numbers suggested by the MIT students who proposed it.
    You caused an intriguing idea in me, maybe an initial estimation of the recovery percentages of the energy producing components in this car could be given as:
    1) A 60%-70% increase in fuel economy by hydraulic hybrid system. 2) Up to 10 percents electricity storing in hybrid cars by hydraulic shock absorbers. 3) Deactivating the motor cylinders or variable cylinders management (VCM) in hybrid Honda accord. Pontiac Grand Perry GXP, equipped with the DOD technology of General Motors, sometimes excludes half of the cylinders and includes them back if needed, to reduce the fuel consumption about 12%. 4) BMW Active E concept. Regenerative braking increases the efficiency up to 20%. 5) Start/stop systems switch off the internal combustion engine if the vehicle is stationary - for example in traffic jams or at red traffic lights. Depending on the vehicle concerned, start/stop systems save up to 5% in the New European Driving Cycle (NEDC) and produce correspondingly less CO2. In the urban part of the NEDC, the reduction in consumption and emissions is as much as 8%.
    Result: 60%+10%+12%+20%+8%=110%! Let alone other involved methods of efficiency-improving. Surely the fuel economy would be less than 100% in reality, but if the above estimations could get close to 70%, that would be a great achievement.
    A linear electric motor can have a couple of configurations. One configuration is equivalent to unrolling a rotating electric motor, while another uses rack and pinion gears to adapt rotary motion to translational motion. In either case, they can be applied as generators. They are equivalent to attaching a shaft to the magnet in one of your linear induction devices, so that it can be driven by an external input, instead of inertia alone.
    I'm aware of the dual roles of them in the electric vehicles as the motor/generator, most famous of all in the regenerative braking mechanism, but I have not dealt with them in my paper at all. Indeed, I have no idea about the motors, current motors in the production EVs of the market are suitable in my viewpoint, my attempt is to provide the force to rotate them.
    Actually, the idea of a mechanically-powered flashlight by shaking, or "shake flashlight" attracted me. Please read this content carefully:
    Mechanically-powered flashlight - Wikipedia, the free encyclopedia
    The linear induction or "shake flashlight" is another design of a mechanically-powered flashlight. It was sold via direct marketing campaigns beginning in 2002.
    This design contains a linear electrical generator which charges a capacitor when the flashlight is shaken lengthwise. The battery or capacitor powers a high-intensity white LED array. In the linear generator, a sliding rare earth magnet moves back and forth through a solenoid, a spool of copper wire. A current is induced in the loops of wire by Faraday's law of induction each time the magnet slides through, which is used to charge the capacitor.
    Simply shaking the light for about thirty seconds provides about five minutes of light. Shaking the unit for 10 to 15 seconds every 2 or 3 minutes as necessary permits the device to be used continuously. The capacitor is used instead of a rechargeable battery since it doesn't wear out like a battery.

    Therefore, to visualize my idea, imagine an EV that has been covered with tens of shake flashlights like this:
    The sliding magnets inside the solenoids would naturally be moved by driving the car on the road. However, it's just beginning of the story. What should be done to optimize their slides or what I call the sensitization procedure, is the set of the methods that I've presented in the plan. It has nothing to do with motors, all the efforts must be focused on increasing the electricity out of their sliding to be conducted to the target set of batteries or supercapacitors.
    Smaller deformations mean that there is less energy to recover from the structure, so later generations of cars are likely to be progressively less suited to this type of energy harvesting. Some theoretical support for this idea could be gained by estimating the deformations experienced by a car body, and estimating the amount of energy that a piezo material could recover from this deformation.
    I have not considered gross deformations of a car to produce piezoelectricity. That would be insane to cause even smallest damage to the car to make electricity by that. In the least condition the pressure of the driver to hold the steering wheel might help to warm it up and a similar story for pressing the seats by the passengers' buttocks! Also, at the most extreme situations we need to consider the naturally intense strain among the body, floor and chassis, plus the pressure the tweels would experience by the weight of the car and the earth reaction.
    Likewise, the linear vibrational inductors are likely to generate little energy, if the manufacturers succeed in providing a smooth ride. This is why this type of generation is probably best concentrated in the suspension system.
    You made me explain more about the solenoid electricity and why I likened it to the blood flow for this car. I know mounting shake flashlight-like pipes beneath the car's skin would not solve the energy demand of the car, in particular at low speeds, so what's the solution? We need to slide those inner magnets artificially. So we need to maximize this relation:

    By increasing the N where is the number of turns of wire, during a shorter time. Read:
    Electromagnetic induction - Wikipedia, the free encyclopedia
    Faraday's law of induction - Wikipedia, the free encyclopedia
    Therefore, if we make a fast back and forth motion for the magnets, we'd be able to increase N. The most effective solution can be inspired by the linear particle accelerator:
    "a type of particle accelerator that greatly increases the velocity of charged subatomic particles or ions by subjecting the charged particles to a series of oscillating electric potentials along a linear beamline. For particle-to-particle collision investigations, the beam may be directed to a pair of storage rings, with the particles kept within the ring by magnetic fields. As the particle bunch passes through the tube it is unaffected (the tube acts as a Faraday cage), while the frequency of the driving signal and the spacing of the gaps between electrodes are designed so that the maximum voltage differential appears as the particle crosses the gap. This accelerates the particle, placing energy into it in the form of increased velocity. Additional magnetic or electrostatic lens elements may be included to ensure that the beam remains in the center of the pipe and its electrodes"
    The mentioned process could push & pull a subatomic particle to nearly the speed of light. I suggested we should do a similar operation for the sliding rare-earth magnets only for make them slide faster and keep their sliding for a longer lifetime. The temporary magnets attract the sliding magnets by opposite poles and repel them by changing their pole to make them accelerate.
    However, I am aware that a sufficiently light linear electric motor is unlikely to generate sufficient force to work well in this application, and that this is why the MIT crew used hydraulics instead.
    Agreed. We can't rely on electromagnetic induction effects completely, we need the help of hydraulic effects too.

  8. #8
    Join Date
    Aug 2011
    Location
    Karaj
    Posts
    91
    The energy contribution from exercise will necessarily be small, and as you point out, may increase range by up to 14km per person contributing. This is a small contribution to the range, and will not, on its own, extend the range of an electric car (100-200km, or so?) to be competitive with a hydrocarbon-powered car. That is not to say that it is not a worthwhile contribution, though. However, 240W is equivalent to a strong cyclist maintaining a rather fast cruise, or a runner maintaining a fast jog. The body heat generated by this activity is likely to require a similar amount of energy to be dedicated to air conditioning to cool the passenger. Also, to be equivalent to the 240W of the solar panel, the contributor would have to maintain this output continuously, for a day, as the solar panel would. That is a big ask.
    Three points that should be noted: 1) This item is useful in critical conditions, when the charge storage is over and the help is not supposed to come soon, the passengers should have a confidence feeling that they might cause the car to move several kilometers ahead. 2) If we assume using the car for inside city purposes, the additional 14 km in range is not a so little contribution. 3) Most important than all, we'd better look at this through a wider perspective, for example in an interval of a year. If this item would cause 400 km additional mileage for a car during a year, calculate the saved electricity from the fossil resources, then multiply it by the number of the cars applying bio-force and obtain a vision of the resulted impact on the environment (& health).
    Eventually, the future advancements in materials engineering might cause bigger contributions for the related devices in this item. I don't see unlikely if rotating a handle for some seconds, would cause you to watch a movie for tens of minutes …
    In addition, another practical consideration is that seat belts are compulsory in much of the world, and I have trouble imagining how safety can be engineered into a treadmill, particularly with the runner's head protruding from the sunroof.
    I've thought about this possibility and my conclusion is running on the treadmill is forbidden for a moving car. When you drive a car, it's too dangerous if somebody would run on the treadmill, even if you drive very slowly. However the treadmill conveyor belt can be run by hand, as I've proposed in the paper …
    I have not seen anyone introduce a measure even this simple, so my hopes for pedal-powered computing are not likely to be fulfilled any time soon.
    The world is crazy. Unfortunately, people would not like this option, unless a couple of disasters like Chernobyl and Fukushima would be taken place, so people might think an easy power can be problematic some times …
    However, such advantages are immaterial, if the system ends up increasing the weight of the vehicle, without appreciably improving the range. This is why I would be interested to see an estimate of the possible energy density of such a system.
    To have a suitable green driving, I suggest we should use both compressed-air and electricity, not only one of them. Thus we could make a balance between the involved advantages and disadvantages. For example to solve the weight increasing problem, I think installing several small compressed-air tanks would be better than a few large ones, so we need more number of them to receive and release the compressed-air quickly, if you could provide a considerable amount of electricity, you'd have no problem to appropriate a part of it to compress the air by electric compressors. I need to study more to give you exact or estimated numbers, but the principles should be as just mentioned.
    Finally, you base your proposals around large and heavy vehicles, which are not a particularly good proposition from an environmental point of view. You also suggest that it should have a bull bar, front and rear, for safety. Safety is not improved by such devices, as they can interfere with the normal operation of crumple zones. They also significantly increase weight and aerodynamic drag, reducing efficiency.
    The platform, class, body, and grille guarding are all optional. I've emphasized this. Although there is a reason for grille guards, if those do nothing but increasing the weight and aerodynamic drag, why do some people use them? I tried to add another application for them, to make solenoid electricity. I repeat there must be a balance among the constrictive factors and destructive effects of weight increasing because of them. As I've pointed out in page 34:
    Moreover, regarding the high price of the carbon fiber and also aluminum, perhaps increasing the car weight by using steel in the body and chassis will not be a bad idea. For example, increasing the strain among the car components and increasing the piezoelectric electricity in result (See the next method 'B' on emphasizing the strain between the body and chassis in favor of making piezoelectricity), is a useful feature of increasing the weight by applying steel. Also, a deeper suspension system to keep vibrating the rare-earth magnets and more producing the solenoid electricity as a result is the second useful feature for using steel. Eventually, more affecting the gravity of the increased mass of the car and more regenerating the kinetic energy while changing the constant velocity by accelerator or brake pedals [16, 17] along with a similar effect on the hydraulic hybrid system [101], might be able to relax the destructive effects of the weight increasing on the propulsion.
    If one extremely insists on weight decreasing, he'd better walk or use a bike. On the other hand, if he insists on having all possible equipments, he's better drive a perfect spaceship!
    It would probably still need the backing of an organisation, to cover the engineering and manufacturing costs, but a small, simple car, designed for both electric and mechanical drive, and with room for modification, would be a good place to start.
    Once somebody told me I should build a small sample to prove it to others it works. I understand no theorization is comparable to that, but costs of making a concept sample is not achievable at all, at least in my location. Honda is a good company, I wish they would know about my plan someday …
    By the way, if your have any chemistry related problems, feel free to explain them. There are several people here who are studying various sciences, so you may find someone who can help.
    Alright, it's a cool idea but quite raw. According to these links:
    [ame="http://en.wikipedia.org/wiki/Hydraulic_hybrid"]Hydraulic hybrid - Wikipedia, the free encyclopedia[/ame]

    [ame="http://en.wikipedia.org/wiki/Hydraulic_Launch_Assist"]Hydraulic Launch Assist - Wikipedia, the free encyclopedia[/ame]

    HowStuffWorks
    There is a working fluid to be pressurized by decelerating. I was thinking what if we could apply another sensitization process to this fact? It sounds like a magic, but if a catalyst, maybe a sort of nano-powder would be added to the target fluid, even small changes in the speed of the car could launch a chain reaction to rapidly increase the pressure and compressibility of the fluid. I guess we need to search for special compounds that might interact with a proper fluid in that desired way …

  9. #9
    Join Date
    Jun 2010
    Posts
    82
    The potential 110% reduction in fuel use are something of an illusion. There are two or three general ways to reduce the fuel/energy use of a vehicle. One is to reduce the amount of energy needed to drive the car, which is best achieved by weight and drag reductions. The second is to improve the efficiency of the power generation, and this grouping includes measures such as cylinder deactivation, engine design improvements, and the use of batteries or fuel cells, with a higher energy conversion efficiency than an internal combustion engine can achieve. The third way is to recover as much wasted energy as possible, via regenerative braking, as well as scavenging by solar panel or vibrational energy recovery. There is overlap, and applying efficiency measures in one area, can influence the efficiency measures used in another area.

    In your listing of the possible energy efficiency gains, you mention two forms of regenerative braking. The efficiency gains from these cannot be simply additive, as you cannot recover the same energy twice, so using both systems will just result in each system recovering less energy, adding up to the same total amount of energy as either one system would recover, if working optimally. Likewise, reducing dependency on the internal combustion engine, using hybrid designs, will reduce fuel use, but will also reduce the benefits of subsequent improvements to engine efficiency. There is also a limit to the improvements that can be made to efficiency. Even assuming perfect energy recovery, and very high drive efficiency, there will still be a minimum energy that cannot be recovered or reduced, which is needed to overcome aerodynamic drag, frictional losses, accessory drives etc. Thus, as you observe, efficiency can never be improved 100%.

    I would not suggest damaging a car for the sake of piezo energy recovery, but piezo energy generation depends upon there being a deformation. For example, the rigidity of a Lotus Elise platform is 11,000 Newton-metres per degree. Each time a wheel hits a bump, some of that force will be generated, and the whole car will twist or bend slightly, before resuming its proper shape, when the force is removed. For a car of a given size, this will translate to a number or millimetres of elastic, reversible but forceful deformation, and I assumed that this is what you planned to exploit for piezo generation. This is also the sort of number that I thought could be used to make an estimate of the generating potential of piezo electric bodies. I admit that it becomes harder to make a theoretical estimate if you are intending to exploit deformations of interior furnishings. Another potential approach would be to investigate the possibility of using piezo electric plastics for the interior, as their self-damping effects could benefit the noise, vibration and harshness levels of the cabin, by reducing vibrations from the dashboard trims, and absorbing ambient noise.

    I think I may have misinterpreted your linear accelerator idea before. I did not realise that you intended to increase the sliding motions by that method. However, that raises another problem. The particle accelerator only accelerates particles because considerable amounts of energy are put into the electromagnets that drive the charged particles. Doing the same for purposes of an inductive generator seems akin to a perpetual motion machine. You propose to use sliding magnets to generate electricity, which you then use to accelerate the motion of the magnets, which then generate more electricity, and so on. If I have read this correctly this time, it has a serious flaw. The purpose of the sliding magnet generator is to turn the kinetic energy of the magnet into electric energy. Because energy is conserved, this will necessarily slow down the magnet, and the only way to speed it up is to feed it more energy. If this energy is electric, you will be draining your stored electricity, in order to put kinetic energy back into the magnet. I may still be missing something, but I cannot see how this can possibly benefit the overall electric energy recovered from the system.

    I appreciate that 14km is a significant distance, particularly in the city, but my point was also that that great a benefit would also be a best case, where you assume that you have a long duration of high output from one or several willing contributors. I would not expect to regularly see such a great range improvement under real conditions. Under emergency conditions, the speed of the car driven by several people pedalling would be very slow, and the benefits of this mode of propulsion, compared with simply pushing the car, would be a bit uncertain - less embarrassment, perhaps?

    The purpose of the grill-guard or bullbar is not crash safety. They are very bad for pedestrian safety, and their intended purpose (in Australia, at least) is to protect the radiator and front trims from impacts with animals on country roads, and from slow impacts with rocks, trees etc. when driving off-road. They are not intended to provide protection from normal traffic accidents, and that is why they are common on country and off-road vehicles. I think I have seen only two since I have been in Singapore, and they were mounted to dedicated off-road vehicles. The few that are attached to city-bound vehicles in Australia generally belong to people who buy them for the wrong reasons - intimidation of other drivers, or protection from low speed accident damage that they should have been able to avoid, for example - and they are the subject of resentment from the rest of the population. Likewise, the generating capacity of sliding magnets in the bullbar is unlikely to offset the added drag of the bullbar, although experiments would probably be needed to confirm or deny this.

    Yes, I agree that the best option for weight reduction is a bicycle, and the bicycle is my preferred choice of transport, for most purposes. If the energy dedicated to pedalling to recharge a car were dedicated instead to riding a bicycle, the cyclist would cover much more distance than the car would using the same power. For this reason, I would expect that if someone were willing to dedicate significant effort to pedalling to charge the car, they would probably prefer to ride a bicycle instead, and this is why I see marketability as a bit of problem for the idea. It is not that it is not capable of making a significant contribution to the range of the car, I just cannot imagine many people choosing to dedicate their energy to travel in that manner, when there are simpler, cheaper and more efficient methods of using the same energy.

    While I understand your reasons for seeing potential benefits from excess weight, bear in mind that improved regenerative braking capacity of a heavier vehicle must be balanced against the increased amount of energy needed to accelerate it. If you can recover 80% of the kinetic energy of the vehicle for reuse, you are still losing 20% of the kinetic energy. If a car weighs twice as much, that 20% will be twice as much energy, in absolute terms, that is lost, even though the 80% recovered is also twice as big. Hence the increased weight will necessarily increase the energy requirements of the vehicle overall. Likewise, the increased strains in the body of a heavy vehicle will have a greater piezo generating capacity, but this must also be balanced against the increased energy losses from the heavier vehicle. Thus, I see a benefit overall only from weight reduction, not weight increase.

    I would guess that using several small tanks instead of one large one would actually make the compressed air system heavier. One of the larger contributors to the weight of such a system would be the weight of the pressure-containing material of the tanks. The amount of material needed would be determined by the surface area of the tanks, and several small tanks will have a greater surface area, for the same contained volume, than one large tank.

    The compressed fluid energy recovery idea is interesting. You might like to look into phase-change fluids. Supersaturated solutions of some salts can undergo phase changes in response to temperature or mechanical disturbance. These tend to be characterised by release or absorption of heat, rather than volume change, but the density of the materials does change, so perhaps, in conjunction with some thermal tricks, they could be put to some use.

    Phase-change material - Wikipedia, the free encyclopedia

    Also, shape-memory alloys and polymers may have some useful properties. Imagine making a spring which could be "switched" on or off. There are a range of shape-memory materials, so there is a chance that one may suit the purpose. Bear in mind that energy will still be conserved. If you make a spring which can release energy at the flip of a switch, you will also need to return the same amount of energy to the spring, or it will not do it again. Likewise with a phase-changing fluid, energy will be needed to change the phase back, and recharge the material. Once again, whatever design you come up with along these lines must have some advantage over existing electric or mechanical energy recovery devices, for it to be useful.

  10. #10
    Join Date
    Aug 2011
    Location
    Karaj
    Posts
    91
    The potential 110% reduction in fuel use are something of an illusion. There are two or three general ways to reduce the fuel/energy use of a vehicle. … There is overlap, and applying efficiency measures in one area, can influence the efficiency measures used in another area. … Likewise, reducing dependency on the internal combustion engine, using hybrid designs, will reduce fuel use, but will also reduce the benefits of subsequent improvements to engine efficiency.
    That's right. I stated this issue is not so simple. It's clear those additive proportions cannot be precise. However, the interesting point is regarding the resemblance between the compressed-air & ICE systems leading to feed a set of cylinders, we could take advantage of the tricks in the ICE such as cylinder deactivation for the compressed-air propulsion as well.
    There is also a limit to the improvements that can be made to efficiency. Even assuming perfect energy recovery, and very high drive efficiency, there will still be a minimum energy that cannot be recovered or reduced, which is needed to overcome aerodynamic drag, frictional losses, accessory drives etc. Thus, as you observe, efficiency can never be improved 100%.
    Now, at this point, I got you! Or if you prefer, you got me! To overcome these limits as you listed, one needs to care about my methods of providing energy while driving. That's like aerial refueling for the military aircrafts, pumping energy from an external source helps you have a different story. It's obvious if you even use enriched uranium as the fuel for your car, someday that fuel would be finished. I am cautious to claim my presented methods, specially the solenoid electricity, would prevent discharging an EV, but since those don't violate the laws of physics, that can't be quite excluded. However, even if those could recover the consumed energy of an EV near to 80-90%, that would be a true revolution in the industry.
    For a car of a given size, this will translate to a number or millimetres of elastic, reversible but forceful deformation, and I assumed that this is what you planned to exploit for piezo generation. This is also the sort of number that I thought could be used to make an estimate of the generating potential of piezo electric bodies.
    Agreed.
    The particle accelerator only accelerates particles because considerable amounts of energy are put into the electromagnets that drive the charged particles. Doing the same for purposes of an inductive generator seems akin to a perpetual motion machine. You propose to use sliding magnets to generate electricity, which you then use to accelerate the motion of the magnets, which then generate more electricity, and so on. If I have read this correctly this time, it has a serious flaw. The purpose of the sliding magnet generator is to turn the kinetic energy of the magnet into electric energy. Because energy is conserved, this will necessarily slow down the magnet, and the only way to speed it up is to feed it more energy. If this energy is electric, you will be draining your stored electricity, in order to put kinetic energy back into the magnet.
    This case is strange to me too. In this car, you have the magnets in sliding status most of the time. You see them sliding unless the car is parked or keeping a constant velocity, even you might see them sliding in the latter condition, because they've started sliding already and the applied tricks have permitted them to keep sliding for a longer duration. The simplest of those tricks is mounting two springs on the tails & heads of solenoids to bounce the magnets after contacting such springs. As it's mentioned in page 31:
    .
    However, the shock absorbers should shake the car body most of the time [103] to increase the solenoids electricity, with a suspension system equipped with coil springs [104]. Specifically because of the earth's gravitational field, the vertical components play an important role in producing the solenoid electricity. Through installing one (hydraulic-piezoelectric) spring at tails and heads of any piece of a defined solenoid, especially the bottom tail, the rare-earth magnets would experience much tossing, and the springs would also give electricity separately.
    .
    Unlike the particle accelerator, the car is in motion and the natural momentum by driving on the road causes the magnets to slide, then some tricks amplify this sliding. Let me quote from the page 32:
    .
    To toss the rare-earth magnets inside the solenoids that are more effective, one should seek ways to increase the velocity and lifetime for oscillating the magnets inside the solenoids. Apart from installing springs as stated above, another solution operates as follows: Both tails and heads of any solenoid can be equipped with a gelatinous object (a plastic, …) to strongly bounce the rare-earth magnet after contact.
    Also, for more vibrations of using a rare-earth magnet inside the solenoid volume, i.e., to move quicker near the mentioned plastics, or plastics to each other, it is proposed that a variable piece inside the solenoid would be composed of (rare-earth) magnetic and plastic parts altogether (See Fig. 37), that resemble the familiar black and white truncated icosahedron pattern of Adidas Telstar-style balls (e.g., white panels denote magnetic parts, and black panels denote plastic parts, albeit the ball is not hollow). Therefore for the task of vibration, the mixed structure of magnet plus the plastic, would function more effectively than a pure magnet structure.
    As another effective means, one can apply active polymer gel actuators [106] that are used instead of plastics in this mixed structure. In fact the active polymer gel actuators would cooperate with the natural momentum caused by road motion, to make further oscillating move for the rare-earth magnets inside the solenoids. The mentioned gels are used locally in the small scales for some tiny electronic devices of the car. By the way, the required starter materials for the reaction by the gels should be provided without using an external source as much as possible, for example we suggest nitrogen must be directly extracted from the air [107].

    .
    Therefore, controlling the sliding magnets depends on the geometry of the related solenoid. In my opinion, integrating all the considered methods would result in something close to an ultimate solution to keep the magnets sliding for most of the time. For example, in a simple linear geometry for a solenoid, the spring might do their jobs well, without any requirement to the driving temporary magnets, or springs might cooperate with the temporary magnets to ease their duty and vice versa. However, for safety considerations, the speed of magnets must not be increased unlimitedly to damage the (head & tail of) solenoids. On the other hand, for a curved geometry of solenoids, e.g., circular, semicircular, … we could allow the magnets to slide with higher speeds. The simple tricks like mounting springs won't work here and we'd need a complex arrangement of temporary magnets. Let me quote again, from the page 33:
    .
    That could be an effective strategy to mount tiny temporary magnets in tails, heads, and in middle of the solenoids, for this amplifying effect (See Fig. 38). The infinitesimal required electricity to launch these tiny inductive magnets in the path, may be supplied by the car power management unit, sourced by the solar cells or other available methods. A related trick can do so: First specify which solenoids give the most electricity during the computer simulations (normally bigger ones), then little solenoids give automatically their initial produced electricity to such tiny temporary magnets of the bigger ones at first, then their extra electricity to the batteries /supercapacitors. The weight increase by magnets and solenoids should not be more than 80 kilograms, as the initial estimation.
    Obviously all of the attempts should be to extract a significant amount of electricity from the car's solenoids. For example the roof rack that possesses an excellent geometry for solenoid-inserting, trivially should compensate its own weight for the propulsion, and beyond that gives contributions to it. Hence it is suggested the involved metals in producing the solenoid electricity, would have a low density.

    .
    An interesting situation can be the roll cage, from page 34:
    .
    There are similar considerations with the grille guarding, about the roll cage [110], being used in the racecars for more safety during accidents. Such considerations can be operated if this car makes high speeds, and if the roll cage won't be in contrast with the comfort and health of the passengers (i.e., side-effects of the produced electromagnetic fields, plus the noise of sliding magnets).
    .
    Anyhow, if this approach fails, it could drain the stored electricity as you said. If it works strongly, it could blow up the batteries / supercapacitors or harshly suck the around air to compress it and maybe we'd have a new problem, because we should think about what to do with this huge amount of created power!

  11. #11
    Join Date
    Aug 2011
    Location
    Karaj
    Posts
    91
    I would not expect to regularly see such a great range improvement under real conditions. Under emergency conditions, the speed of the car driven by several people pedalling would be very slow, and the benefits of this mode of propulsion, compared with simply pushing the car, would be a bit uncertain - less embarrassment, perhaps?
    Bio-force should not be counted as a separate contribution. It's mixed with other methods of charging the car and only the car's computer could calculate the quantity of this service. Even if an EV would activate this option to add averagely one kilometer to its mileage every day and if we assume this car is being driven 200 days for a year, the owner has saved 200 km via this approach, a help to the environment and his health.
    Also, I should predict the emergency conditions before happening them as a driver and suggest my passengers to pedal or handle when the car is still running. I should do this regarding my destination and amount of electricity storage, otherwise I admit that would be a difficult and improper task for the passengers to do bio-force when the storage is quite over. That might work to propel a lost car in middle of nowhere for remarkable distances, if the passengers would use their muscles for more than two days. Absolute most of the people are unable to do that. They would need much food, rest and motivation to do that. I hope the solenoid electricity never would allow this awful scenario.
    The purpose of the grill-guard or bullbar is not crash safety. ... Likewise, the generating capacity of sliding magnets in the bullbar is unlikely to offset the added drag of the bullbar, although experiments would probably be needed to confirm or deny this.
    I appreciate your info on the bull bar. So you must be Australian? That's cool. I hope my proposed car could ride around your vast country someday, without any serious problem for charging. Anyway, the grille guard is not a necessary part of the car. It can be simply forgotten if it would not give us considerable amount of energy.
    I see marketability as a bit of problem for the idea. It is not that it is not capable of making a significant contribution to the range of the car, I just cannot imagine many people choosing to dedicate their energy to travel in that manner, when there are simpler, cheaper and more efficient methods of using the same energy.
    I like this to be a part of my car package. If somebody dislikes this, he could ignore it. If somebody really dislikes this, he could refuse to order it at the first place, before buying his car. However, when he's stuck in a heavy traffic jam behind red lights, he might regret for lacking this possibility to be not passive in a limited space. This option as rotating handles or pedaling unconsciously might bring him peace in physically, mentally, financially, and environmentally aspects. Personally, sometimes inside the car, it gives me nervous pressure by thinking I'm in a closed space and I can't walk or jump freely. Also, in an excursion some people might want to try the most used muscles do not have to be necessarily the muscles for talking!
    I know marketing for a product that makes people passive is easier than marketing for a product that encourages them to be active. However, its sounds a good picture if some people might think this way sometimes:
    By rotating this handle for one time, I just served the earth and my body one time.
    By rotating this handle for two times, I just served the earth and my body two times.
    By rotating this handle for three times, I just served the earth and my body three times …
    Thus, I see a benefit overall only from weight reduction, not weight increase.
    What if weight reduction would mostly give us less safety and lack of propulsion? I'm glad you mentioned the balance demand. We need a specific balance degree to offset the involved factors. Thus complicated calculations and computer simulations along with experimental test are required. We can debate about this forever, but we need to wait and see what are the nature's replies and what are the consumers' preferences?
    I would guess that using several small tanks instead of one large one would actually make the compressed air system heavier. One of the larger contributors to the weight of such a system would be the weight of the pressure-containing material of the tanks. The amount of material needed would be determined by the surface area of the tanks, and several small tanks will have a greater surface area, for the same contained volume, than one large tank.
    Another subject including good and bad features. Such tanks should be made by lightest possible materials like aerogel. If we assume compressed-air storage would be finished fast (& would be filled up fast actually), those should be in small sizes. I like this choice. However, if we assume it's not supposed to be finished fast like an ICE car, it should be large. This item needs more technical discussions …
    The compressed fluid energy recovery idea is interesting.
    Thanks for the data on this topic. I prefer don't comment and leave it to someone with enough science of chemistry. I'm just saying that is awkward this propulsion is limited to the large vehicles that stop more than usual during a path. We should modify the fluid to be applicable in the small car properly, albeit that must be environment-friendly.

  12. #12
    Join Date
    Jun 2010
    Posts
    82
    Quite a lot of Australia's wide, open spaces would suit solar panels very well, and they could reasonably make a noticeable contribution to the range or economy of a car being driven for long distances in the outback. In the cities, solar panels would probably have potential to slowly charge a car, while it is parked in the sun for most of each day. On the other hand, in Singapore, a highly efficient energy recovery system, like the hydraulic system used in trucks, would probably vastly improve economy, because people here seem to drive fast, and stop quickly and frequently for traffic lights, to pick up or drop passengers, or just for fun.

    Logically, I would expect the magnets to be suspended between two springs, so that they can oscillate like a sprung pendulum. This would prevent any impact on the magnets, and would allow their continued movement until all of their kinetic energy has been recovered. If you wanted to optimise their efficiency, you would ensure that the solenoid and magnet is contained inside a sealed, evacuated tube, so that there would be no aerodynamic drag, or air compression effects on the magnet. It might not be necessary to use an external structure, like a roll-cage or roof rack, to contain them, as the structures of modern cars generally use quite large-diameter hollow sections for parts like A and C pillars, in order to ensure crash and rollover safety. These structures could contain solenoids without encroaching on passenger space or external airflow, and could make the solenoids invisible to the passengers.

    I still believe, however, that any energy amplifying design will be largely destined for failure, as it would violate the first law of thermodynamics for a device like that to generate more energy overall than the kinetic energy imparted to the magnet by the movement of the device. When the movement of the magnet generates electricity, the magnet is subject to magnetic drag. This is why the magnet does not suffer harsh impact in a shaken torch, even if it is shaken quite hard. The electric induced drag on the magnet increases as the magnet's speed through the solenoid increases, and tends to limit the magnet to a fairly constant speed. Likewise, the magnets in your proposed solenoids will be retarded by magnetic drag, and that is how they will create an electric current. The only way to make them move faster or further is to give them more energy than they are losing to the solenoid; that is, to feed them more energy than they will generate. Ultimately the only energy that can be gained from the solenoids is the kinetic energy they recover from the movements of the car.

    The efficiency of a car can be vastly improved, as you say. However, there is still a limit to how much it can be improved. Energy that would otherwise be wasted, via braking or suspension movements, or even noise and heat, can be recovered, at least partially. There will still be a minimum amount needed to propel the car, that cannot be recovered or reduced, without affecting the movement of the car by slowing it down. Because the thermodynamic efficiency of internal combustion engines is pretty bad, there is plenty of room for reduction of energy use - perhaps to the order of 80-90%, as you say. But my point was that even if you had a drive system that is 100% efficient, and you recovered all possible energy from vibrations and oscillations in the car structure, from braking and from the suspension movements, etc., your drive system would still have to supply some energy to overcome aerodynamic drag, frictional drag, climate control, radio, lighting, power-assisted steering etc. in the car. There is a lot of room for improvement, but travel will never happen without some energy being consumed in the process, and this is the minimum limit of the energy needed to propel a car.

    One of the benefits of light weight is the ability to do without some accessories, like power-assisted steering and brakes. Safety arguments directed at light, small cars also tend to be misleading. Yes, a small car being hit by a big car generally comes off worse than the big car. However, this argument leads to an arms race, where cars get progressively larger and heavier, to provide protection from the larger and heavier cars they will come up against. It has escalated in recent years, partly because of the rise in popularity of four-wheel-drives as city cars. Cars now are larger and heavier than they have ever been, at any other point in history. Safety of small cars would be equivalent to that of large cars, if they could be reasonably assured of hitting a similarly sized car. Fortunately, the drive for economy has resulted in a slight shift back towards smaller, lighter cars, but it will take time for weights in general to come down to sensible levels. In addition, small cars are designed to withstand impacts with larger cars much better now than they did before, so even in a world of heavy cars, their safety is not as bad as many people believe.

    That manufacturers have been able to improve fuel consumption in the face of this bloating, is an achievement, but the improvements could be so much greater if weight was reduced, instead of increased. As an extreme example, Daihatsu launched a concept 700kg Kei-car, with automatic engine stop-start as its only notable economy measure. It ran on a small, naturally aspirated petrol engine, and used 3.3 or 3.4 litres per 100km. That is better than any hybrid or any diesel economy model that is currently on the market, yet it is also cheaper than any economy special, and uses no particularly advanced or expensive technology. Likewise, Audi's original A2 was a small car made almost entirely out of aluminium, and had a low drag coefficient. It was as practical as any other small car, but had a fuel consumption as low as 3L/100km for the turbo-diesel economy variant, and 5L/100km for the normal petrol variants. This was achieved via low weight, low drag and minimal accessories, such as power-assisted steering or air conditioning, in the economy model.

    As I said, I do not believe that lowering weight will reduce energy generating capacity in any meaningful way, as a lighter car always needs less energy to propel itself, all other things being equal. In fact, the pitching movements that tend to be inherent short wheelbase cars would probably increase the effectiveness of the solenoids, by increased body movements. As I said, I believe that reduced weight can only benefit range and efficiency, and that increased weight can only be detrimental. The above fuel consumption figures were achieved with conventional, inefficient drive systems, and the economy is largely attributable to light weight and low drag. I would like to see just how low the fuel consumption could be if the light weight and low drag were combined with highly efficient drive systems, and energy recovery methods.

  13. #13
    Join Date
    Aug 2011
    Location
    Karaj
    Posts
    91
    Quite a lot of Australia's wide, open spaces would suit solar panels very well, and they could reasonably make a noticeable contribution to the range or economy of a car being driven for long distances in the outback. In the cities, solar panels would probably have potential to slowly charge a car, while it is parked in the sun for most of each day.
    The future of this field is bright. The solar electric generation has the highest power density (global mean of 170 W/m²) among renewable energies. However, currently the best achieved sunlight conversion rate (solar panel efficiency) is around 21% in commercial products[3], typically lower than the efficiencies of their cells in isolation. The Energy Density of a solar panel is the efficiency described in terms of peak power output per unit of surface area, commonly expressed in units of Watts per square foot (W/ft2). The most efficient mass-produced solar panels have energy density values of greater than 13 W/ft2 (140 W/m2). According to this link:
    Solar cell efficiency - Wikipedia, the free encyclopedia
    Solar cell efficiencies vary from 6% for amorphous silicon-based solar cells to 40.7% with multiple-junction research lab cells and 42.8% with multiple dies assembled into a hybrid package.[7] Solar cell energy conversion efficiencies for commercially available multicrystalline Si solar cells are around 14-19%.[8] The highest efficiency cells have not always been the most economical — for example a 30% efficient multijunction cell based on exotic materials such as gallium arsenide or indium selenide and produced in low volume might well cost one hundred times as much as an 8% efficient amorphous silicon cell in mass production, while only delivering about four times the electrical power.
    The additional 14 km to the car's mileage by mounting a sunroof in Canada (at 2007) was mentioned above. It's unknown how many hours did the experiment last and how much was the efficiency of the used solar panels (at best assumptions, 22%). Therefore, as I've suggested the solar panels should be usable at night in Ref. [36], after reading these news (at 2010):
    New solar cells even work at night
    Scientists harvest solar power - in the dark | SmartPlanet
    One finds out the achievement of the U.S top nuclear laboratory has an estimated overall efficiency of 46%, more than double of the efficiency of that Canadian test. Also, if we assume those Canadian cars were used the sunlight for 8 hours during the experiment, that fact that new type of solar cells continue to work after the sun goes down by absorbing infrared radiation, enables one to triple the duration of using them to 24 hour for day & night, if he parks the car having such solar panels, outdoors, not his garage. In result, that 14 km additional mileage could be converted to 14Χ6 = 84 km additional mileage! This result is great, even if it would be 70 km as an approximation, that's great again. However, it seems we can't be so optimistic to see such achievements in the market for a near future, due to a report by a publication of the Federation of American Scientists, and also this page. It's disappointing that:
    Thus, the 1971 list indicates that patents for solar photovoltaic generators were subject to review and possible restriction if the photovoltaics were more than 20% efficient. Energy conversion systems were likewise subject to review and possible restriction if they offered conversion efficiencies “in excess of 70-80%.”
    According to this link:
    Invention Secrecy Still Going Strong | Secrecy News
    Fortunately, all regions of the world do not obey such stupid laws. For instance, Germany:
    World Record: 41.1% efficiency reached for multi-junction solar cells at Fraunhofer ISE Fraunhofer ISE
    If I would use such dreamy solar panels on my car and make my domestic animal(s) to run on an exterior-of-car treadmill for one hour daily, the piezoelectricity and hydraulic shock absorbers would supply my power demand for nearly all the usual conditions. Only for a long journey I might require to use the power from grid or the controversial solenoid electricity. About the bio-force affairs, the bigger animal the better. That animal should not be smaller than a big dog, a sheep is good and a horse or cow is great, albeit the poor animal should not be exhausted by running!
    If you wanted to optimise their efficiency, you would ensure that the solenoid and magnet is contained inside a sealed, evacuated tube, so that there would be no aerodynamic drag, or air compression effects on the magnet. It might not be necessary to use an external structure, like a roll-cage or roof rack, to contain them, as the structures of modern cars generally use quite large-diameter hollow sections for parts like A and C pillars, in order to ensure crash and rollover safety. These structures could contain solenoids without encroaching on passenger space or external airflow, and could make the solenoids invisible to the passengers.
    Agreed. It's a vital practical challenge how to make a vacuum inside the solenoids and more importantly, keep it for an appropriate duration. One trick could be designing the electric compressors, in which they would start compressing the air from the interior of the solenoids. That would function like a vacuum cleaner, but we need something more to make the solenoids empty from every other thing, but sliding magnets.
    Also, it's logical to care about the appearance of the car. I prefer all the additional equipments to be invisible to the passengers, as much as possible. The car should be beautiful at outside, and powerful at inside.
    I still believe, however, that any energy amplifying design will be largely destined for failure, as it would violate the first law of thermodynamics for a device like that to generate more energy overall than the kinetic energy imparted to the magnet by the movement of the device. When the movement of the magnet generates electricity, the magnet is subject to magnetic drag. This is why the magnet does not suffer harsh impact in a shaken torch, even if it is shaken quite hard. The electric induced drag on the magnet increases as the magnet's speed through the solenoid increases, and tends to limit the magnet to a fairly constant speed. Likewise, the magnets in your proposed solenoids will be retarded by magnetic drag, and that is how they will create an electric current. The only way to make them move faster or further is to give them more energy than they are losing to the solenoid; that is, to feed them more energy than they will generate. Ultimately the only energy that can be gained from the solenoids is the kinetic energy they recover from the movements of the car.
    Certainly, the solenoid electricity mechanism has to respect the laws of thermodynamics. I accept the amplifying may be impossible, but I think about high amounts of recovering and beyond that. How? Apart from providing a perfect vacuum inside the solenoids, we can make power after sliding-magnets contact to the springs, by piezoelectric and hydraulic effects. Also, to make this more efficient, we should combine it with other less efficient methods in this car. For example, if the efficiency of the solenoid electricity is 60% in usual conditions and entering the driving temporary magnets to the equation would make that 90%, we should appropriate the less efficient available method, say solar electricity with 20% efficiency, to empower those temporary magnets. That's the case for the relation among the smaller and larger solenoids, and other methods of harvesting power while driving. Notice, it has nothing to do with the stored electricity before driving, in this situation.
    On the other hand, to make them slide faster, we need to seek for the solutions that are independent from the car motion, one of them that was mentioned in the paper is the active polymer gel actuators. This brings more complexity to the solenoids configuration, but it leaves only two main problems for solving: aerodynamic drag & frictional losses; besides I believe it does worth to be reviewed, in order to get rid of the fossil fuels.

  14. #14
    Join Date
    Aug 2011
    Location
    Karaj
    Posts
    91
    The efficiency of a car can be vastly improved, as you say. However, there is still a limit to how much it can be improved. Energy that would otherwise be wasted, via braking or suspension movements, or even noise and heat, can be recovered, at least partially. There will still be a minimum amount needed to propel the car, that cannot be recovered or reduced, without affecting the movement of the car by slowing it down. Because the thermodynamic efficiency of internal combustion engines is pretty bad, there is plenty of room for reduction of energy use - perhaps to the order of 80-90%, as you say. But my point was that even if you had a drive system that is 100% efficient, and you recovered all possible energy from vibrations and oscillations in the car structure, from braking and from the suspension movements, etc., your drive system would still have to supply some energy to overcome aerodynamic drag, frictional drag, climate control, radio, lighting, power-assisted steering etc. in the car. There is a lot of room for improvement, but travel will never happen without some energy being consumed in the process, and this is the minimum limit of the energy needed to propel a car.
    You're right. As I just said, there would be only two problems from the ones you listed: aerodynamic drag & frictional drags. The others are minor problems. Even we could think about some solutions to overcome those drags. For instance, let's consider noise and heat: In fact, the howl of the air flow, out of the car in high speeds is a consequence of the aerodynamic drag, so as I've proposed in page 37, it could recover a part of the consumed energy. This method is new and has good advantages:
    Thermoacoustic heat engine - Wikipedia, the free encyclopedia
    There is a similar story to recover a part of aerodynamic drag that causes heat in nearly all points of the car's exterior, and frictional drag that causes some heat around the wheels. As it's cited in page 38, this is another approach in the category of "physical effects". Unfortunately at present, the efficiency of using the [ame=http://en.wikipedia.org/wiki/Thermoelectric_generator]thermoelectric generators[/ame] is low.
    At last, it should be noted there are at least two main discussions about an electric vehicle: Providing the power, and storing the power. All my efforts are about providing the power, if the efforts on the storing the electricity would be taken into account, e.g., improving the batteries, supercapacitors, & related technologies, we'd face a more pleasant picture. That's not fair to fight in a battle lonely, I need backup!
    One of the benefits of light weight is the ability to do without some accessories, like power-assisted steering and brakes. Safety arguments directed at light, small cars also tend to be misleading. ... so even in a world of heavy cars, their safety is not as bad as many people believe. ... That manufacturers have been able to improve fuel consumption in the face of this bloating, is an achievement, but the improvements could be so much greater if weight was reduced, instead of increased. ... This was achieved via low weight, low drag and minimal accessories, such as power-assisted steering or air conditioning, in the economy model.
    I agree on the spirit of your opinion about the weight reduction for the cars. Note my proposed car is a 7-seater vehicle, and it naturally cannot be so light. I believe we could provide the green driving, even for the large vehicles having accessories of ventilation and recreation affairs. The green cars does not have to be limited to small, light, aerodynamic-shaped vehicles. It's not constructive to be obsessed with the weight, if there is much weight at work, why don't we take advantage of it?
    I would like to see just how low the fuel consumption could be if the light weight and low drag were combined with highly efficient drive systems, and energy recovery methods.
    Me too.

  15. #15
    Join Date
    Jun 2010
    Posts
    82
    I know that large cars, for example people movers, will inherently be heavier than small cars. However, there are large cars that have achieved remarkable economy by virtue of reduced weight via clever engineering. The current model Jaguar XJ is a very large car, but having a structure made out of aluminium, it weighs 150kg less than a comparable limousine, and is largely recyclable. In combination with one of the world's best diesel engines, it is capable of an combined 7.2L/100km, for the long wheelbase variant. This is less than the fuel consumption of a Toyota Corolla, which has about half the power, and is quite considerably smaller and less luxurious.

    A recent trend in America, Australia, and other countries with cheap petrol, has been to provide seven seats by buying a four-wheel drive, such as a Toyota Landcruiser. The same number of seats, and similar usable space is available from a large people-mover, and the same number of seats with less usable space is available from a smaller people-mover. In both cases, the people-mover is considerably lighter than the four-wheel drive, if for no other reason than they are not encumbered by the four-wheel drive system. They also tend to be easier to drive, and more stable, because of their lower ride-height and slightly smaller size than an equivalent four-wheel drive. For this reason I maintain that, even amongst large, spacious vehicles, there are lighter and heavier, and more and less sensible choices. I do not object to large cars fundamentally, but I do object to wasteful, inappropriate or irresponsible choices of vehicle.

    If the number of passengers on board, and fuel use per passenger per km are taken into account, a seven seater would probably return better fuel consumption than a two-seater. However, my point is that the excess size and weight for its own sake, may increase the energy recovery opportunities, but they will not reduce fuel consumption overall. Likewise, a seven-seater may be more efficient than a two-seat Honda Insight, but only if all of the seats are filled, minimising fuel use per passenger per km. If the drive to work, or the shops, is considered, a seven seater with one person, or one person and some shopping inside, will always use more energy than an equivalently designed small car - a two or four seat car. While I think you are right to consider the energetics of moving large numbers of people in one vehicle, the principles that you want to apply should also be applicable to a small car, and should not depend upon heavy vehicles to work. This is not a criticism of your ideas for energy recovery, just a suggestion that the presentation of your ideas should not depend upon them being applied to large or heavy vehicles.

    Consider the approach that established manufacturers have taken to efficiency. Hybrids and electric vehicles, for example, that gain their competitiveness from energy recovery, began with the two seat, light weight Honda Insight, and gradually gained weight and diversity via the Prius, the Civic hybrid, and eventually vehicles like the Lexus RX400h four-wheel drive, and Lexus GS450h, and LS600h limousine. The application to larger and heavier vehicles came after the development of the smaller and lighter models that the technology actually suited very well.

    In fact, an interesting comparison can be made between the GS450h and the Jaguar XJ. The Jaguar is the larger car, but it is lighter than the Lexus. The Lexus claims 250kW total system output, and 0-100km/h in 5.9 seconds. The long wheelbase Jaguar, with the 3L diesel engine, claims 202kW, and 0-100km/h in 6.4 seconds. The Lexus claims a fuel consumption of 7.7 L/100km, while the Jaguar claims 7.2L/100km. That is 0.5L/100km better, from a larger car with no energy recovery or hybrid systems, and fairly comparable performance. That is the benefit from an efficient engine combined with a light weight body.

    The comparison is more pronounced with the LS600h, which is a closer match for the size and market segment of the Jaguar. The LS600h is over 500kg heavier, accelerates to 100km/h in 6.3 seconds, uses 2.1L/100km more fuel, and claims a combined system power output of 327kW. Courtesy of the excess weight of the hybrid system, and the relative inefficiency of the petrol engine, the hybrid is substantially heavier, less efficient and not appreciably faster, despite its considerably greater power output, than the relatively light diesel car. To top it off, the Lexus has a boot almost 200L smaller than the XJ. This is the kind of situation where the excess size and weight of the energy recovery systems adds up to a less efficient, less practical car.

    With regard to the solar panel problem, given time, I believe that the efficiency of solar panels will improve, and production costs will drop, as a result of both research into materials and designs, and the development of fabrication techniques that can produce them economically. There is still considerable interest in renewable energy, so investment is still being made in such areas. As for the production of a vacuum in the solenoid tubes, this should be easily possible, and should not require an on-board vacuum pump. I envision the solenoids being sealed, possibly by welding or heat-sealing, depending upon the choice of material. I know from experience that a quite high vacuum will persist for several years, assuming the right materials, and method of sealing. Once sealed, they should be maintenance-free for quite a long time.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •