Chinese Farmer Creates Wind-Powered Car

I've often wanted to build something like that :)
Drachen_Jagersays...

That is the dumbest thing I've ever seen.

Don't people know you can't get energy from nowhere? The fan produces friction, that friction creates electricity, but it also slows the car down, the amount produced will never surpass the amount of energy spent pushing the car forward. Additionally there is inevitable loss in the generator, wiring and batteries.

It is impossible to build a wind turbine generator on a car that increases efficiency through wind generated by the vehicle's own travel.

Everyone involved in the production of that bit needs remedial physics classes.

Barbarsays...

I'm not so sure, Drachen.

If the car was going to push that air anyways, then there would be less additional drag from the turbine, no? This isn't the same situation as attaching the turbine to the top of the car, or having it stick out the side. We're concerned about the net effect on the vehicle's drag.

If I'm not mistaken, then this energy is not coming from nowhere, but is rather a portion of the energy being wasted to push the air in front of the car that is being returned.

Will it ever be enough to drive the care on it's own? No, I don't think so, without significant modifications and a steady breeze. But that doesn't mean it can't contribute to the vehicles efficiency.

All this is little more than idle speculation though. I def need to read more on the drag effects of turbines.

AeroMechanicalsays...

I would guess he would find better efficiency by reducing drag. That big fan on the front is definitely not reducing drag. However, since it isn't increasing the frontal area of the car, its effect on drag probably isn't massive. Of course, then taking into account the extra mass of the fan itself and the generation hardware, I would be willing to bet that it results in a significant net loss in efficiency.

Additional: I gotta say, I do find it really odd that he would have the skills necessary to build the thing, but not the common sense to see its obvious flaw.

Barbarsays...

Doesn't seem like that fan weighs more than 5 pounds or so. A generator can be small enough to fit in a flashlight. Sure that won't generate the power we're looking for, but it's not like it'd require something the size of your car's alternator either. Also, he mentioned 40 mph, I think, as the point at which it become beneficial. I expect he's done the calculations to know when it's worth doing. I'd give him the benefit of the doubt here, he obviously knows more about his prototype than any of us do, and he's obviously not a fool.

bobknight33says...

Capitalism at work in China. 1 inverter living his dream.


Socialism at work in America. In America our government forces GM to produce the Chevy Volt. Very little people buy them since they cost $100,000. The buyer pays $40K and the Tax payer eats the $60K.

rkonesays...

>> ^Drachen_Jager:

That is the dumbest thing I've ever seen.



Agreed. I'd downvote the video if I could. People, if you're in doubt, think of it this way - if the fan could generate more power than the loss of pushing it, then you could just keep adding more fans until it becomes a perpetual motion machine..

Stormsingersays...

>> ^AeroMechanical:

I would guess he would find better efficiency by reducing drag. That big fan on the front is definitely not reducing drag. However, since it isn't increasing the frontal area of the car, its effect on drag probably isn't massive. Of course, then taking into account the extra mass of the fan itself and the generation hardware, I would be willing to bet that it results in a significant net loss in efficiency.
Additional: I gotta say, I do find it really odd that he would have the skills necessary to build the thing, but not the common sense to see its obvious flaw.

It's effect is to increase the drag by exactly as much as the energy the generator produces, plus enough more to offset the inefficiencies of said fan and generator.


You -cannot- gain efficiency this way, that's basic physics. If you disagree, I suggest you head back to high school for a refresher.

jqpublicksays...

I think it's more likely that this system extends the drive time of whatever battery cells he has installed in the thing. It's not that he's getting free energy, it's just that at 40 the system is going fast enough that even though there's a net loss, the additional energy stored in the batteries gives a longer running time. I think that's just about all that there is here.

>> ^rkone:

>> ^Drachen_Jager:
That is the dumbest thing I've ever seen.


Agreed. I'd downvote the video if I could. People, if you're in doubt, think of it this way - if the fan could generate more power than the loss of pushing it, then you could just keep adding more fans until it becomes a perpetual motion machine..

Sniper007says...

Two 30 minute test drives would definitively demonstrate the case either way. One trip without the fan operating. One trip with the fan operating. Which method leaves the batteries with more juice (or goes farther before dying, etc).

It's so remedial a solution, you have to believe he's done it.

GeeSussFreeKsays...

>> ^jqpublick:

I think it's more likely that this system extends the drive time of whatever battery cells he has installed in the thing. It's not that he's getting free energy, it's just that at 40 the system is going fast enough that even though there's a net loss, the additional energy stored in the batteries gives a longer running time. I think that's just about all that there is here.
>> ^rkone:
>> ^Drachen_Jager:
That is the dumbest thing I've ever seen.

Agreed. I'd downvote the video if I could. People, if you're in doubt, think of it this way - if the fan could generate more power than the loss of pushing it, then you could just keep adding more fans until it becomes a perpetual motion machine..



Problem, nothing happens at 40 miles an hour in physics for a decrease wind resistance and drag. If anything, the faster you go, the more of a problem wind becomes. There is no possible way that this is extending his drive time. This is exactly equal to holding your hand out the window. If you could turn that blockage into electricity, it will always be less energy than the amount of momentum it sapped via drag. Or else ALL CARS WOULD ALREADY DO THIS! The reason you don't is because it doesn't work.

A simple instance where something like this IS used is the emergency ram air turbine for jumbo jets. When there is a complete loss of power, a ram air turbine drops down to generate emergency power for the hydraulic systems. This increases drag, but it is so small that it isn't a problem. But it is also why air planes don't have windmills on them, anything you use to block the wind is slowing you down more than any recoverable amount of energy via electric conservation of kinetic energy. This is physics 101, entropy, it's a bitch!

Now, if he compressed the incoming air, added a combustion chamber with kerosene or gasoline, then he would have himself a turbine engine for his car, but now, he just has a lesson in why physics is hard.

Stormsingersays...

>> ^bobknight33:

Capitalism at work in China. 1 inverter living his dream.

Socialism at work in America. In America our government forces GM to produce the Chevy Volt. Very little people buy them since they cost $100,000. The buyer pays $40K and the Tax payer eats the $60K.


"Capitalism at work in China. 1 inverter conman living his dream."

Fixed that for ya.

This is just another perpetual motion machine. You cannot violate the second law of thermodynamics, which would be required for this to work.

AeroMechanicalsays...

Maybe we'll pass by each other in the hallways while you're on your way to your reading comprehension class.

>> ^Stormsinger:

>> ^AeroMechanical:
I would guess he would find better efficiency by reducing drag. That big fan on the front is definitely not reducing drag. However, since it isn't increasing the frontal area of the car, its effect on drag probably isn't massive. Of course, then taking into account the extra mass of the fan itself and the generation hardware, I would be willing to bet that it results in a significant net loss in efficiency.
Additional: I gotta say, I do find it really odd that he would have the skills necessary to build the thing, but not the common sense to see its obvious flaw.

It's effect is to increase the drag by exactly as much as the energy the generator produces, plus enough more to offset the inefficiencies of said fan and generator.

You -cannot- gain efficiency this way, that's basic physics. If you disagree, I suggest you head back to high school for a refresher.

Stormsingersays...

>> ^AeroMechanical:

Maybe we'll pass by each other in the hallways while you're on your way to your reading comprehension class.
>> ^Stormsinger:
>> ^AeroMechanical:
I would guess he would find better efficiency by reducing drag. That big fan on the front is definitely not reducing drag. However, since it isn't increasing the frontal area of the car, its effect on drag probably isn't massive. Of course, then taking into account the extra mass of the fan itself and the generation hardware, I would be willing to bet that it results in a significant net loss in efficiency.
Additional: I gotta say, I do find it really odd that he would have the skills necessary to build the thing, but not the common sense to see its obvious flaw.

It's effect is to increase the drag by exactly as much as the energy the generator produces, plus enough more to offset the inefficiencies of said fan and generator.
You -cannot- gain efficiency this way, that's basic physics. If you disagree, I suggest you head back to high school for a refresher.


Sorry, I guess I wasn't clear. I wasn't disagreeing with anything -you- said except to change "willing to bet" into "absolutely certain". All the physics-challenges posts previously got my frustration levels up, and demanded a response. Yours was one of the few reasonable starting points (as opposed to the utterly uninformed majority).


Most of those earlier posts had a knowledge of physics similar to thinking that mounting a fan blowing on the sail of a sailboat would make it move. Quoting that sort of thinking is giving it too much credit.

rottenseedjokingly says...

Now if he used the heat from an engine to create steam that could turn a turbine, THEN we'd be talking...



(I know the weight of the water needed to do this would far outweigh the energy production benefits, I was being a silly goose)



(I should've just used sarcasm)



(I'm new here...tee hee)

zeoverlordsays...

sure it is, first case would be if it's used to correct turbulent air that would otherwise cause extra drag, in such a case it would have a double effect, both by reducing drag and generating power.
Second case would be if you had a turbine with deployable blades that extend every time you brake, sure the gain would be small, but it is a gain non the less.

Though clearly this car does not use either of these, and the only way this would add energy instead of wasting it was if he lived in a really windy place.
>> ^Drachen_Jager:

It is impossible to build a wind turbine generator on a car that increases efficiency through wind generated by the vehicle's own travel.

KrazyKat42says...

If you had to frequently speed up and slow down, you might get a small net gain in efficiency. When your foot is off of the gas (?) pedal, the electric usage is zero, but the fan is still producing energy.

A similar idea is used in electric cars with magnetic brakes. They slow the car with electromagnets and charge the battery at the same time.

Drachen_Jagersays...

First case is simply wrong. Wind generators are turbulence generators, period. If they don't generate drag they don't work.

As for the second case it would be far more efficient to simply have the electric motor work in reverse so that it uses the car's momentum to generate electricity AND braking power. No need for fancy extra gadgets that would cost tens of thousands per unit and would never be more efficient than a simple system converting momentum to energy through the drivetrain.

>> ^zeoverlord:

sure it is, first case would be if it's used to correct turbulent air that would otherwise cause extra drag, in such a case it would have a double effect, both by reducing drag and generating power.
Second case would be if you had a turbine with deployable blades that extend every time you brake, sure the gain would be small, but it is a gain non the less.
Though clearly this car does not use either of these, and the only way this would add energy instead of wasting it was if he lived in a really windy place.
>> ^Drachen_Jager:
It is impossible to build a wind turbine generator on a car that increases efficiency through wind generated by the vehicle's own travel.


robbersdog49says...

Whenever I see something like this I always think 'how do the people running these scams get away with it?'

Then I read the comments here and realise people are far too uninformed to understand the problems. I'm not going to say stupid, just uninformed. Physics, science generally and maths are seen as geeky subjects studied by nerds which can be safely ignored by the cool kids because they'll never need them in real life. This leads to the completely uninformed comments above. Anyone who thinks this could work is wrong. If you think it will extend the range you are wrong.

There is a hell of a lot of money to be made from fuel efficiency in cars. Which do you think is more likely: Ford, BMW, Mercedes, VW, Honda, Toyota, Volvo, GM, Dodge, et al with all the hundreds of millions of pounds or dollars or Yen or whatever they spend on development missed something a farmer in China was able to build in his garage - or the farmer in China is wrong? Add to the car makers all the companies who make planes and trains and boats and it shows a pretty obvious fact.

Yep, the Chinese farmer is wrong. Simple.

But the worst thing about this video is that it exists. I'm sure farmers all over the world come up with stupid ideas all the time (as do people from other walks of life too!), but that doesn't mean they need to make a video about it.

Barbarsays...

The point I was making was that if air passes through the turbine, (I am assuming) it leaves with a portion of the turbine's forward velocity imparted upon it. If this is the case, then doesn't it mean that the car's chassis, following directly behind the turbine will experience less drag, since the relative wind speed is lower? So if the drag on the car's chassis is reduced, and a portion of the drag increase from the turbine is gathered by the generator, doesn't it get a bit more complicated? Again, this isn't the same as the trivial example of a fan on a sail boat (which due to triangular sails and keels actually can work in a very limited fashion).

Yeah I know this is only likely to make me look more stupider, but I'm okay with that.

Drachen_Jagersays...

>> ^Barbar:

The point I was making was that if air passes through the turbine, (I am assuming) it leaves with a portion of the turbine's forward velocity imparted upon it. If this is the case, then doesn't it mean that the car's chassis, following directly behind the turbine will experience less drag, since the relative wind speed is lower?


You'd have to do extensive wind tunnel testing, but I suspect the turbulent air following the fan's passage would actually make the rest of the car drag more. Look at properly done wind tunnel testing, it's all about smooth flow, the most aerodynamic model is the one with the least eddies in the wind. In this model you propose there are tons of eddies and unpredictable wind currents before you even begin to introduce the body of the car.

If you could somehow design something that worked as you propose (which I doubt is possible, but it might be if you threw enough money at the problem), the infinitesimal gain would almost certainly be lost through the inefficiencies introduced by the necessary (for safety) fan shroud, and the generator itself.

Drachen_Jagersays...

>> ^Sniper007:

Two 30 minute test drives would definitively demonstrate the case either way. One trip without the fan operating. One trip with the fan operating. Which method leaves the batteries with more juice (or goes farther before dying, etc).
It's so remedial a solution, you have to believe he's done it.


It's not as easy as that. Measuring how 'full' a battery is has never been managed to a sufficiently accurate level to compare. Better would be to equip the car with several volt-meters and ammeters, recording the input and output of electricity.

braschlosansays...

The only way something like this would work is a device that captures waste heat and turns it back into usable energy. BMW made a system like this that took waste heat from the exhaust and put it back into the crank.

Also some of you need to go back to high school (middle school perhaps)

Barbarsays...

I'm not sure why people seem to think this is an elementary problem. I seriously doubt that most people in this discussion studied anywhere near the math and physics required in the calculation in middle school, or even high school, or college for that matter. Having studied physics and math at all those levels, I know that wind turbines were NEVER part of the discussion. After looking up the relevant equations, I can see why -- they're certainly not trivial, and would probably required significant calculus to understand (derive). In university my physics courses were directed towards electricity, so I didn't get a chance to play with wind tunnels -- although I'd still love to!

Applying the oversimplified version of laws that you learned in early physics classes to reality can often leave you in stunned silence when reality seems to defy them. Things like the dimples on golf balls or sailing ships moving upwind are classic examples of things that you wouldn't expect to even be conceivable unless you saw it in action.

robbersdog49says...

>> ^Barbar:

Applying the oversimplified version of laws that you learned in early physics classes to reality can often leave you in stunned silence when reality seems to defy them. Things like the dimples on golf balls or sailing ships moving upwind are classic examples of things that you wouldn't expect to even be conceivable unless you saw it in action.


Conceivable or not, none of the things you mentioned break the first law of thermodynamics.

One situation where the system could work would be if the car was driving into a strong headwind. This would give an energy input into the system. It could be perhaps developed to extend the blades if there is a strong enough headwind, and retract them if there isn't, but if there is no breeze, there will be a net loss from using the blades.

If the car is driving through stationary air then the air it's passing through will have no kinetic energy. After passing over the blades the air will be moving, it will have gained kinetic energy. That energy will have been taken from the car. It's as simple as that. No complicated equations needed. You'd need the complicated equations if you wanted to calculate exactly how much energy is lost, but you don't need them to see that energy would be lost.

If wind is factored into it then the air already has kinetic energy, which would be extracted by the fan, but the wind would be and external source of energy (in the same way that a wind turbine isn't in any way a perpetual motion device, it's obvious where the energy is coming from).

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