perpetual energy machines

[mozirry]

I'm not even sure if its possible to have a perpetual energy machine, but it is something that I think about every now and then to see if its plausible.


What about wind power on moving cars? Obviously cars stop, but once on a highway and you are moving at a constant high speed, there is a strong airflow moving all around your car, correct?

If we were to stand a wind-powered generator on the outside of a vehicle in face of the high speed draft of air, it would spin the propeller, correct?

Now, my question is, once the car has hit speed using it's own conserved energy, would it be possible to have the wind-powered generator generate enough electricity to continue powering the motor to keep the car moving at a constant speed?

What we have here is the car moves at a constant speed, the wind then moves at a constant speed, spinning the generator at a constant speed, which generates electricity at a constant amount which in turn powers the car's motor to move at that constant speed.


I think a big hole in my theory here may be that there would be so much wind resistance that the car would need a huge amount of power to over come that resistance. I don't know much about how much energy a wind-powered generator can produce and how much energy is required to keep a small electric car at a constant speed

 

[dkozloski]

Originally posted by: mozirry
I'm not even sure if its possible to have a perpetual energy machine, but it is something that I think about every now and then to see if its plausible.


What about wind power on moving cars? Obviously cars stop, but once on a highway and you are moving at a constant high speed, there is a strong airflow moving all around your car, correct?

If we were to stand a wind-powered generator on the outside of a vehicle in face of the high speed draft of air, it would spin the propeller, correct?

Now, my question is, once the car has hit speed using it's own conserved energy, would it be possible to have the wind-powered generator generate enough electricity to continue powering the motor to keep the car moving at a constant speed?

What we have here is the car moves at a constant speed, the wind then moves at a constant speed, spinning the generator at a constant speed, which generates electricity at a constant amount which in turn powers the car's motor to move at that constant speed.


I think a big hole in my theory here may be that there would be so much wind resistance that the car would need a huge amount of power to over come that resistance. I don't know much about how much energy a wind-powered generator can produce and how much energy is required to keep a small electric car at a constant speed

Surely you jest.

 

[imported_Rat]

I'm not even sure if its possible to have a perpetual energy machine

It isn't.

Every propellor you put on the car would create additional drag, meaning it would require more energy to power the car. Combined with the fact that wind turbines are not 100% efficient, it wouldn't even pay for itself. Not to mention the car's innate drag and the friction of all the engine parts.

Hybrid automobiles recycle some of the engine power normally lost when braking. When the brakes are presed, the weight of the moving car is used to power an electric generator. The mechanical resistance from the generators helps stop the car.

 

[frostedflakes]

I don't think this is even a perpetual motion machine. To be classified as a perpetual motion machine, not only must it violate the laws of physics (i.e. making them impossible, at least based on our current understanding of physics), but it must continue moving w/out external sources of energy (such as wind). So it would not be a perpetual energy device, just a very efficient car.

 

[Howard]

Perpetual motion only means that something keeps moving, right? Things do that in the absence of friction and other forces.

 

[Xyo II]

Originally posted by: Howard
Perpetual motion only means that something keeps moving, right? Things do that in the absence of friction and other forces.

Throw a softball in space. Chances are, it will keep on going for enough time to be considered "perpetual motion", a couple hundred million years.

 

[BrownTown]

I'm still debating whether this thread is a joke or if the poster was jsut really stoned when they wrote it.

 

[pcy]

Hi,

Originally posted by: mozirry

Now, my question is, once the car has hit speed using it's own conserved energy, would it be possible to have the wind-powered generator generate enough electricity to continue powering the motor to keep the car moving at a constant speed?

No.




Peter

 

[bobsmith1492]

You could just put a big sail on the top of it; then, the wind gives you energy and you just keep going and going and going....

but that still doesn't fit the definition of a perpetual motion machine; to do so, it must keep moving without any external input of energy.

 

[alpha88]

Reading this post made my spleen hurt.

 

[RadiclDreamer]

The properller would create drag so you lose more momentum from it than you would gain by turbine

 

[Kelnoen]

I was thinking about perpetual motion, can you get working magnetic insulators?

 

[BrownTown]

Laws of Thermodynamics

 

[Pulsar]

Hrpmhf.

Any time I see a bunch of meaningless pointless posts where it appears that the poster may be drunk I ask myself "Did school just get back in session?"

 

[dkozloski]

Intelligence is finite and can be measured but there is absolutely no limit to stupidity.

 

[Gibsons]

Really cool site with a lot of perpetual motion machines Text

none that actually work, of course.

 

[mozirry]

http://www.bergey.com/images/Bergey-&-Randy-at-SS.sm.jpg

mount that on top of an electric car without the long pole

seriously, I'm going to make millions of dollars!!

We will all peddle around the globe with free electricty at 25 mph!

 

[DrPizza]

I don't think the wind idea would work, but how about welding a pole to the front of your car and attaching solar cells... then, if you had an electric car, you could just turn on the headlights and go

 

[CycloWizard]

There are a few problems with your scheme, some of which others have pointed out already. To ensure no net loss of energy, one must eliminate the energy sinks in the problem (i.e. external forces). These are:

1. Internal friction (piston versus cylinder, transmission frictions)
2. External friction (wheels versus ground)
3. Drag (car body versus air)
4. Thermal inefficiencies (chemical potential energy of raw fuel versus work done by engine)

I listed these in what I would guess is increasing inefficiency (i.e. thermal inefficiency is the largest cause of wasted energy and internal friction is the least cause).

For #1, one must come up with a better lubricant. Lubricants are quite advanced now such that this is not a major energy sink.

For #2, one would have to come up with improved tire or road materials with smaller asparity length scales to decrease the coefficient of friction. Improving tire tread design has some minimal impact on this as well.

For #3, one must make the body more aerodynamic. Since large-scale simulations of boundary layers are still computationally intractable at high Reynolds numbers, this is still mostly achieved empirically (since I believe the computation time scales as the cube of the Reynolds number at best). I think Ferrari spent something like 600,000 hours in a wind tunnel with their latest car.

For #4, one could spend more money on exotic engine materials (e.g. titanium-nickel superalloys) and change fuels to run at insanely high temperatures like jet engines. This isn't really a feasible solution, however, due to the expenses involved. Instead, one might trade the internal combustion engine (~13% efficiency) for a fuel cell (~90% efficiency), but this would also require a societal paradigm shift and insane infrastructural investment, as well as lots of time. One must also consider how the fuel for the fuel cell will be generated, usually using a larger-scale internal combustion engine (e.g. coal power plant -> electricity -> electrolysis). Owing to the scale of power plants, they have a much greater efficiency than do automobile engines and the net energy loss would be greatly decreased. The amount of the efficiency improvement depends on the type of power plant, with nuclear having the highest efficiency.

Your solution would only address #3, though whether it would have a net positive or negative impact on efficiency depends on many factors.

 

[msparish]

Originally posted by: CycloWizard
There are a few problems with your scheme, some of which others have pointed out already. To ensure no net loss of energy, one must eliminate the energy sinks in the problem (i.e. external forces). These are:

1. Internal friction (piston versus cylinder, transmission frictions)
2. External friction (wheels versus ground)
3. Drag (car body versus air)
4. Thermal inefficiencies (chemical potential energy of raw fuel versus work done by engine)


Your solution would only address #3, though whether it would have a net positive or negative impact on efficiency depends on many factors.

Um...there's no way for what he described to have a positive effect.

 

[randay]

Try telling that to Herbie the lovebug!

 

[Jeff7]

Couldn't I just put a gear on a generator, and put that gear to a gearbox that goes to 5 other generators, and get 5x more power than from just one generator?

 

[CycloWizard]

Originally posted by: msparish
Um...there's no way for what he described to have a positive effect.

Actually, there is, though it's likely unachievable in practice and could probably only help at all at low speeds. If the mini-windmills were designed such that they put off the boundary layer separation on the car (assuming that the boundary layer is laminar, which is why I added the caveat that it would be at lower speeds), overall drag could be reduced. This, coupled with a purely efficient dynamo, would result in a positive increase. There's always a way, in theory. Perhaps a more realistic way would be to pop the windmills out during breaking. This would stop the car faster and recover more energy than the hybrids existing today.

 

[randay]

Originally posted by: Jeff7
Couldn't I just put a gear on a generator, and put that gear to a gearbox that goes to 5 other generators, and get 5x more power than from just one generator?

and then 5 more gears on each of those 5 gears and so on and so forth until we have unlimited power!

 

[sillycheesedude]

I am currently drunk, and I can tell you for a fact that my purpetual motion machine works like a charm.