Compressed air car far as 1000 miles at up to 96 mph with each tiny fill-up

[Moses]

Originally Posted by Truckerjo

What do you mean by HUGE energy required to compress the air?
How does $2-$4 per fill = huge energy?

And again if a tank ever ruptured (highly unlikely event) it would not be a rocket because there would be no fuel, just air.... I would be more concerned with the hybrid cars with electric motors powered by batteries having an issue with rupturing, this would be more of a concern in many different ways, but they can be purchased now at the dealership today...

Just because electricity off the grid is cheap doesn't mean there isn't a lot of energy involved in packing a cylinder with 4500 psi of air. How hot does an air compressor get when it's pumping up your brakes at 120 psi? All that heat is wasted energy. Pump up a truck tire with a bicycle pump and tell me there's no energy required to compress air.

Check out the Mythbusters episode where they blow up a charged SCUBA tank; that thing takes off like the proverbial ape. I don't know if there's 4500 psi in one of those, but escaping air exerts a force (otherwise the CA engine wouldn't work in the first place) and Newton's first law says there will be a reaction.

As for hybrids and batteries, I agree wholeheartedly. You'll never convince me that by adding weight and complexity you end up with a more efficient machine. Strip a Prius of its 900 pounds of batteries and run it on a small turbodiesel. I bet you'd double the mileage.

The aircar's theoretical range on pure air is 7 minutes at WOT, 109 minutes at 5 hp draw. It uses a gasoline engine to power an onboard compressor. So it's a hybrid without the batteries. With each stage of energy conversion (fuel to gasoline engine, gas engine to compressor, compressor to tank, tank to motor, motor to motion) there is some loss of efficiency. I'd be shocked if it breaks 30% thermal efficiency in the real world. A modern car will double that.

MDI's testing in New Zealand yielded a practical range (on air alone) of between 4 and 5 miles. That's about 996 short of the range quoted in the article.

There's a reason this technology has been dormant since the 1860's. My guess is somebody's working a scam on would-be investors.

But what do I know. If I had any brains I wouldn't be in the trucking bidness.

[Truckerjo]

Originally Posted by Moses

Just because electricity off the grid is cheap doesn't mean there isn't a lot of energy involved in packing a cylinder with 4500 psi of air. How hot does an air compressor get when it's pumping up your brakes at 120 psi? All that heat is wasted energy. Pump up a truck tire with a bicycle pump and tell me there's no energy required to compress air.

Dont see where this leads? so, your saying that the HEAT generated is the large amounts of energy.. Well in comparison to a combustion engine I would not considered HEAT from generating air is even close to what a combustion engine would..

So, I don't see any reason for heat in being a factor at all..

Check out the Mythbusters episode where they blow up a charged SCUBA tank; that thing takes off like the proverbial ape. I don't know if there's 4500 psi in one of those, but escaping air exerts a force (otherwise the CA engine wouldn't work in the first place) and Newton's first law says there will be a reaction.

I know the episode your speaking of, I am a mythbuster viewer. The tank is not made of the same material that the tank you are talking abut on the episode, so this is another non issue with this car.. Nor was the tank attached to a car but simply was set out alone.. If the tank was attached to a large object like one of these cars it would not have enough power to "launch like a rocket"

As for hybrids and batteries, I agree wholeheartedly. You'll never convince me that by adding weight and complexity you end up with a more efficient machine. Strip a Prius of its 900 pounds of batteries and run it on a small turbodiesel. I bet you'd double the mileage.

Cool

The aircar's theoretical range on pure air is 7 minutes at WOT, 109 minutes at 5 hp draw. It uses a gasoline engine to power an onboard compressor. So it's a hybrid without the batteries. With each stage of energy conversion (fuel to gasoline engine, gas engine to compressor, compressor to tank, tank to motor, motor to motion) there is some loss of efficiency. I'd be shocked if it breaks 30% thermal efficiency in the real world. A modern car will double that.

Perhaps but the cars that are being developed today are not using a combustion engine (although there are some being developed to use combustion engines) The cars are indeed Hybrides but use electricity and momentum to power pumps, thus making it an electric/compressed air car..

MDI's testing in New Zealand yielded a practical range (on air alone) of between 4 and 5 miles. That's about 996 short of the range quoted in the article.

True the MDI seems to be leading but the 4-5 mile is old news.. They have successfully tested air cars that go Weill beyond that on a fill up.. The 1000 miles quoted are hybrid cars that would be electric combustion generator air to fill the tanks..

There's a reason this technology has been dormant since the 1860's. My guess is somebodies working a scam on would-be investors.

That's just silly, all kinds of technologies have been dormant far as transportation's go... Some would say big oil has stalled many of them.. Some would say there was no need for them.. whatever the reason is there always have been many alternative ideals to the combustion engine but always have been downplayed...

Americans like big fancy cars that catch alot of wind and are heavy.. New technology will not power those types of vehicles without alot of development.. That takes alot of money something most companies will not spend unless there is a need... Now there is a need due to the cost of oil so people will start looking for alternatives..

But what do I know. If I had any brains I wouldn't be in the trucking bidness.

That would be 2 of us but I am no longer trucking so I may be a step ahead of you


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Then with the right backing there is no doubt in my mind that a car that can 100% keep refueling itself with the turning of the wheels to generate air, to run a compressor that would replace the air being used to generate that speed could be developed..
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It will happen becuase there is a need now...

[Moses]

Originally Posted by Truckerjo

Dont see where this leads? so, your saying that the HEAT generated is the large amounts of energy.. Well in comparison to a combustion engine I would not considered HEAT from generating air is even close to what a combustion engine would..

So, I don't see any reason for heat in being a factor at all..

Waste heat is always a factor. It's why IC engines only get 60% of the energy out of a gallon of fuel. The rest goes into the atmosphere through the radiator. Batteries and electric motors get pretty hot under sustained load as well. Again that's energy that's not being used to propel the vehicle.

I know the episode your speaking of, I am a mythbuster viewer. The tank is not made of the same material that the tank you are talking abut on the episode, so this is another non issue with this car.. Nor was the tank attached to a car but simply was set out alone.. If the tank was attached to a large object like one of these cars it would not have enough power to "launch like a rocket"

Doesn't matter what the material is, if it ruptures with 4500 psi behind it, there's going to be a good push there. Assume the vehicle weighs 2250 pounds (and we could really use some 2250 pound vehicles) and the rupture is a 1" circle; that's enough to lift it off the ground, til the air runs out.

My last job was building UAV's, so I know a little bit about thrust and composite materials I'm sure a good carbon/Kevlar tank would do the job and withstand just about any stress that a ground vehicle could put on it. Indy and F1 cars take some horrible crashes and it's been years since a fuel cell has ruptured. But they're not charged with 4500 psi, either.

Perhaps but the cars that are being developed today are not using a combustion engine (although there are some being developed to use combustion engines) The cars are indeed Hybrides but use electricity and momentum to power pumps, thus making it an electric/compressed air car..

Ugh, batteries again? The article mentioned this as being a non-electric 100 mpg car.

That's just silly, all kinds of technologies have been dormant far as transportation's go... Some would say big oil has stalled many of them.. Some would say there was no need for them.. whatever the reason is there always have been many alternative ideals to the combustion engine but always have been downplayed...

The one that's been dormant lately has been old-fashioned gas misers. The early 80's had cars that would do 50 mpg. True, a lot of them were miserable little crap wagons, but let's see some innovation from the automakers. With a modern, efficient powertrain and going easy on the power seats and airbag count, a 4-passenger car that hits 100 mpg highway wouldn't be that hard to do.

Americans are used to having it all. We're driving 400 hp SUV's that weigh 3 tons, and crying about the price of a fill-up. Whose fault is that?

I rented a VW Polo the first time I took the Mrs. to the UK a few years ago. The thing never got less than 45 mpg, and it would hit 100 mph on the motorway (had to, to keep up with traffic), had enough power accessories that it wasn't a total stripper. 1.2L 3-banger gas engine, 5-speed manual. A diesel version would do very well over here in these times. Are we ready to drive hatchbacks again?

Then with the right backing there is no doubt in my mind that a car that can 100% keep refueling itself with the turning of the wheels to generate air, to run a compressor that would replace the air being used to generate that speed could be developed..
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It will happen becuase there is a need now...

There's plenty of doubt in my mind. You're describing a perpetual-motion machine, a dream since DaVinci's time. Heat, friction, and less-than-perfect efficiency will ensure that just ain't happening.

Let's say you're the most brilliant engineer the world has ever seen, and you've managed to design a car, and each of its systems operates at 99% efficiency. That's an order of magnitude above today's standards.

Here's how it breaks down.

The engine is 99% efficient.
So is the transmission.
So are the driveshafts (yes there is a loss with driveshafts; U-joints get hot and heat is energy)
So are the wheel bearings.
So are the tires.
The body has such low drag that it can be said to be 99% efficient.
Regenerative braking recovers 99% of the energy of a stop, and puts it into a battery that is also 99% efficient.
The battery cables, speed controller and processor are 99% efficient.
The hybrid electric motor runs at 99% effieciency, through 99% wheel hubs.

Multiply all those 99%'s together, and your vehicle is now 89.5% efficient. 10.5% is wasted, and that's with totally unrealistic efficiency numbers. And, we haven't used any energy for climate control, a radio, lights, etc.

I remain skeptical. Sorry for the mega-post.

[Truckerjo]

And as usual, the energy equation doesn't work out. A huge amount of energy is required to compress the air in the first place, and much of it is wasted as heat into the atmosphere.

Then morphs to this

Waste heat is always a factor. It's why IC engines only get 60% of the energy out of a gallon of fuel. The rest goes into the atmosphere through the radiator. Batteries and electric motors get pretty hot under sustained load as well. Again that's energy that's not being used to propel the vehicle

I said

Originally Posted by Truckerjo
Dont see where this leads? so, your saying that the HEAT generated is the large amounts of energy.. Well in comparison to a combustion engine I would not considered HEAT from generating air is even close to what a combustion engine would..

So, I don't see any reason for heat in being a factor at all..

Enough said, putting the two quotes together should allow the point to be understood..

Doesn't matter what the material is, if it ruptures with 4500 psi behind it, there's going to be a good push there. Assume the vehicle weighs 2250 pounds (and we could really use some 2250 pound vehicles) and the rupture is a 1" circle; that's enough to lift it off the ground, til the air runs out.

Well then you must not be the expert as you say you are wit carbon fiber materials.. They claim that it will composite fiber tank will not allow a small rupture, but will crack allowing much more air to escape at once.. so there is no lifting because it is not a small hole but a giant whoosh of air with alot less force..

Are you taking the time to even read about this before you type? because your responses contradict the material being published..

Quote:
Perhaps but the cars that are being developed today are not using a combustion engine (although there are some being developed to use combustion engines) The cars are indeed Hybrides but use electricity and momentum to power pumps, thus making it an electric/compressed air car..
Ugh, batteries again? The article mentioned this as being a non-electric 100 mpg car.

Electricity to power the on board compressor (plugging it into the wall) no batteries..

The one that's been dormant lately has been old-fashioned gas misers. The early 80's had cars that would do 50 mpg. True, a lot of them were miserable little crap wagons, but let's see some innovation from the automakers. With a modern, efficient powertrain and going easy on the power seats and airbag count, a 4-passenger car that hits 100 mpg highway wouldn't be that hard to do.

I don't understand how you can narrow it down to only one that has been dormant "lately" (i don't remember "lately" even being mentioned in your last post) and they already have cars that can go 100 MPG but they are diesel powered.. (can't buy them at the dealer yet neither) I would think technology that shows just as much potential using no oil also would be important, if not more important...

Heat, friction, and less-than-perfect efficiency will ensure that just ain't happening.

Combustion engine was said to be impossible, flying faster then sound was considered impossible, putting a man on the moon was considered impossible

The fact is technology that has been considered impossible at one time is always being developed.. making a compressor that can fill the tanks up faster then what is being released out of them, does not seem impossible but feasible with enough research and development...

[Moses]

Originally Posted by Truckerjo

Well then you must not be the expert as you say you are wit carbon fiber materials.. They claim that it will composite fiber tank will not allow a small rupture, but will crack allowing much more air to escape at once.. so there is no lifting because it is not a small hole but a giant whoosh of air with alot less force..

Are you taking the time to even read about this before you type? because your responses contradict the material being published..

Hey, thanks for the personal attack I never had to build an air tank, but I did make a few black-powder cannons from carbon/Kevlar, just for grins.

Failure mode all depends on how the tank is stressed. It could delaminate, split open, or puncture. None of them are terribly likely if the tanks are built to aircraft spec, but there is still danger due to the high pressure. But for the moment let's drop it. I'm not going to get into the Special Olympics of internet arguing.

I don't understand how you can narrow it down to only one that has been dormant "lately" (i don't remember "lately" even being mentioned in your last post) and they already have cars that can go 100 MPG but they are diesel powered.. (can't buy them at the dealer yet neither) I would think technology that shows just as much potential using no oil also would be important, if not more important...

By "lately" I mean since 1990 or so.

Whether it's powered by gas, diesel, compressed air, electric or pixie dust, efficiency is the key factor. Light weight, low drag. And I stand by the assertion that little attention has been paid, as today's vehicles all favor style and performance over efficiency (and yes, I know the industry is market-driven, but people buy cars like children buy food). Example: when's the last time you saw a 14-inch wheel on a passenger car? With smaller wheels you have less rotating mass, smaller brakes are needed, and there's more interior room to boot. But people want to roll on 20's so they can look like playas. Even the concept drawing for the aircar has huge wheels, although the 6-passenger van seems to be more realistically configured.

Combustion engine was said to be impossible, flying faster then sound was considered impossible, putting a man on the moon was considered impossible

And back in the 30's we were supposed to have personal Zeppelins and flying cars (some impractical examples of which were built, more like a small plane with detachable wings). By the 50's Ford put forth a concept vehicle powered by a nuclear reactor under the hood. Technology makes many false starts before something worthwhile is pursued.

The fact is technology that has been considered impossible at one time is always being developed.. making a compressor that can fill the tanks up faster then what is being released out of them, does not seem impossible but feasible with enough research and development...

That part is easy. But you'll never power it off the air from the compressor itself. I'd love to see it, but your faith is misplaced. The first law of thermodynamics is working against you. Crack that nut and we'll be in your debt forever. Start here: [LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link.

[Truckerjo]

Fist It wasn't a personal attack, just pointing out something since you brought up that you know about composite materials and how they work, being you made UAV's and all.. The tanks don't "puncture" as you are suggesting, if they are punctured they crack creating a much larger hole allowing much more air to be released at once..

That part is easy. But you'll never power it off the air from the compressor itself. I'd love to see it, but your faith is misplaced. The first law of thermodynamics is working against you. Crack that nut and we'll be in your debt forever. Start here: [LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link.

Your talking about a temperature change to produce work.. A Compressed air engine is a pneumatic actuator that creates useful work by expanding compressed air. perhaps I should of not said "compressor" and should of said a "system" that could fill the tanks faster then what is being used, without oil (other then lubrication)

[Moses]

It still won't work. You're asking for a machine that's over 100% efficient (self-sustaining), and that dream has eluded better minds than yours or mine for a thousand years.

Thermal efficiency is merely a measure of energy in vs. energy out. Not so much due to temperature change/expansion, like in a CA or steam engine, but work expressed as units of energy. Stored energy as fuel/electricity/air pressure in, kinetic energy as motion out. And it's always less than 1:1.

[Truckerjo]

Originally Posted by Moses

It still won't work. You're asking for a machine that's over 100% efficient (self-sustaining), and that dream has eluded better minds than yours or mine for a thousand years.

Thermal efficiency is merely a measure of energy in vs. energy out. Not so much due to temperature change/expansion, like in a CA or steam engine, but work expressed as units of energy. Stored energy as fuel/electricity/air pressure in, kinetic energy as motion out. And it's always less than 1:1.

No, efficiency is merely a measure of energy in vs. energy out.. Thermal has to do with temperature (heat/cold)

In [LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. , thermal energy is the [LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. portion of a [LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. that increases with its [LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. . In a loose sense, "thermal energy" is a term used to describe the energy content of a system related to [LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. effects, e.g. temperature increase or decrease. In [LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. , thermal energy is the [LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. present in a system in a state of [LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. by virtue of its temperature.[LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. The term is not widely used, however, in a rigorous sense, owing to the result that the phrase "thermal ([LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. ) energy" is counter-intuitive. That is, "thermal energy" can only be defined as any spontaneous flow of energy (energy in transit) from one object to another, caused by a difference in temperature between two objects; thus, an object cannot possess "heat".[LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. This is explained by the [LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. . Hence, by extrapolation, it is difficult to define quantities of heat energy (thermal energy). In isolated cases, however, a few definitions do exist.
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[Moses]

Now we're splitting hairs and getting into angels on pinheads. from the Wiki:

When transforming [LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. into [LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. , the thermal efficiency of a [LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. is the percentage of heat energy that is transformed into [LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. . Thermal efficiency is defined as



Thermal energy can be potential (stored in fuel) or kinetic (performing work) or as you stated, a simple measure of temperature.


Since heat (energy that you pay for) is lost at every stage of energy conversion, the CA car has too many conversions to have any hope of working from an thermal-efficiency standpoint. Dinosaur-fueled vehicles take a very dense and energy-rich fuel and turn it directly into motion with no intermediate steps.


I'm going to bow out and let you pursue your perpetual-motion machine rather than continue with this.

[Truckerjo]

okay if you don't want to pursue that's cool.. I sure hope you wasn't taking this an an argument but simply a discussion... kind of hard to get that across sometimes on forums, and people blow up when somebody disagrees with them... kind of like the CB , you just pull on over and we can talk about it... lol