add a wind turbine to a car?

DaveC426913

Still no.

In order for the turbines to generate power, they must produce drag.

OmCheeto

True. But the design of trucks is so dreadfully bad in the first place, I can't imagine something streamlining the back end, not making the vehicle more efficient, even a bunch of mini-turbines.

But as I think I implied in my previous post, simply making the vehicle more aerodynamic is much more economical. And I should probably add now, that it is the only logical solution.

The article associated with the image of the truck I posted, stated that the gas mileage went from 25 to 32 mpg @ 70 mph, a 28% improvement. I agree with you that a slew of mini-me turbines, strategically placed, would probably not come close to generating such an improvement.

russ_watters

Adding wind turbines the the back end of a truck does not make it more streamlined, it makes it less streamlined (as was already said). Adding a turbine to anything makes it have more drag than it had before you added the turbine.

dec2012omg

I was thinking about this last night.
Surely a wind turbine on top of a car as it travels at speed would generate free energy.
Even if it only powers 20% of the car, this would be a great success for our planet.

I think it is definately possible. One of us just needs to design it and show the formulas to prove it would be more fuel efficient. 'The energy is in the wind'

Borg

The point is that the formulas have been determined a long time ago. They are basic and clear. You can't get something for nothing. If you get power from the wind, it ultimately came from the power that you put in via gasoline.

xxChrisxx

It would yield a net loss in energy.

Remember this golden rule:
When searching for efficiency, anything that affects the thing you want will yield a net loss.


We are using an engine to push the car forward, the point is that using this motion to power a wind turbine will take speed fromthe motion, meaning the engine has to work harder to push the car forward.

engine > motion > wind turbine

As you can see adding a wind tubine to a car is basically just powered by the egine enyway.

However if you had a wind tubine that operated only when the engine was not causing motion (going down a large hill say) THEN you would get a gain.

TO get "free" energy (you dont get something for nothing), you need to get it from things that would otherside be thrown away.w Which is why adding a tubine to the exhaust would work.

russ_watters

Welcome to PF. I'm not sure how to explain it any clearer than it already has. The wind moves a wind turbine by appying a force to it in the direction the wind is moving. In other words, for a wind turbine on top of the a car moving forward, the wind pushes it backwards -- slowing the car.

pronjay

OK so the turbine causes drag, but you have the momentum of the car so maybe you would get a slight overall net gain of energy i.e. enough to power a mobile phone...?

pronjay

yeah but you have the momentum of th vehicle so doesnt this more than counteract the drag?

xxChrisxx

Read the above.

If you take energy from something useful. You LOSE!

Ie it would be more energy efficient to simply use the electricity generated by the engine.

engine > altenator > phone
engine > motion > wind tubine > phone.

It adds more steps the energy has to take when ultimately it comes form the same source.

DaveC426913

Yup. pr0nChrispr0n is right. It's all coming from the gasoline anyway. Why put more steps in between? You've already got a source of electricity.

xxChrisxx

russ_watters

Momentum isn't energy. Momentum isn't force either.

Please understand: we aren't saying that the turbine doesn't generate energy, we are just saying that the turbine steals that energy from the car's engine.

Ranger Mike

i agree...you can not get something for nothing ...what you can do to improve things is to capture and utilize the high temperatures produced by the IC..both antifreeze in the cooling system and waste exhaust.. this is going to waste and..the drag produced by radiator opening could be reduced/eliminated to up the MPG.
there it is...available energy in the form of heat..going to the atmosphere...convert this and you got the ticket!!

dr dodge

hmmm..."turbine on the exhaust".....
what about perm magnets on the intake turbocharger rotor

"antifreeze in the cooling system and waste exhaust"
big peltier device to change heat transfer to electricity

(from my understanding with an engineer here that worked with peltier devices they will produce electricity from temp transfer, although not as effieient as power in to transfer heat)

given as much as most cars sit vs drive, the wind turbine would work good with a "docking station" for the hybred car

just not a good idea on the car at speed

dr

DaveC426913

Would cause back-pressure on the exhaust system.
You're expending energy getting the thing up to speed, then you're going to steal that energy for somewhere else???

You're not thinking critically. You're just pointing at components and asking if it's possible to tap energy from them.

OK, stick one on your roof then. If there's access to the grid (which is why there's a docking station there) then there's no point to attaching a wind turbine at the docking station. Attach it somewhere in the grid that's more efficient for function and just have wired into the grid.

The whole point of what we're talking about is devices on the car when you don't have access to recharging or refueling.

russ_watters

Like a turbocharger...? Or you could use the turbine directly to power a generator. Yes, but it is already an energy recovery device, so you probably don't gain any more by doing this. If you mean waste heat recovery then yes. Correct. Correct.