The Wind Turbine Idea
 

Reading other threads the wind turbine idea often comes up. And the aerodynamic drag will not compensate for the savings in electrical load and therefore FE.

BUT, most cars already have a wind turbine in front of them. The radiator fan if electric is also an electrical generator, as all motors are (just the efficiency changes).

So if one were to want to try the wind turbine in front of the car idea, you already got one in front of your car :)

A little bit of ducting to get more air through it would be helpful.

Unfortunately I do not have the time to try this idea out at the moment, but when time permits I will try to give it a shot.

Some one with a volt and amp meter that has the cables easilly accessible might give it a go.

Going completely alternatorless might become feasible for very low power consumption cars. And the electrical signal to trigger the fan could go to a double throw relay to put the fan back in to fan mode from generator mode.

I read somewhere that some ships have a free wheeling fan at the front of their conning tower which deflects the wind sideways, and allows men to stand behind it, with no wind. I have considered a track, similar to those on a tank, which would roll counter to the direction of travel, cover the upper part of the car, and sides, and roll at the speed of the car, so that the air the car passes through doesn't see a moving body, but only a track which moves with the wind at the same speed. I wish I could draw an animation.

It will be a huge aero penalty that will more than replace any savings from going alternator less.

I am not suggesting it is a bright idea. Just pointing out that it is there and can be tested by those that believe it is a good idea.

I am personally curious how many watts can be extracted from the fan. And if it is such a huge aerodrag then it can be used as an aerobrake on demand.

Watts out as a generator roughly equal to watts consumed as motor

Think about the relationship between air pressure and air velocity.

You might get regen out of an electric prop plane.

I don't think there'd be that much of an aero penalty, as that's already exacted by air flowing through the radiator. My guess is that it'd be the other way around: flowing through the radiator has slowed the air enough that you'd be hard-pressed to get useful energy from it.

Two immediate issues that I can see...

If it's a series-wound motor, you're going to have a hard time getting anything out of it...

and...

If it's a permanent magnet motor, you'll not be able to get enough air flow to make it spin fast enough for it to put out the 12v+ you're looking for. Unless you like driving stupid fast.

Point. But if you *can* get useful energy from it, you're going to be slowing air going through the radiator further, increasing drag. I could certainly see it being used as a "regenerative aerobrake" though.

Before you all get too far down this rabbit hole, does anyone have evidence that a clutched or electric radiator fan spins of its own accord when the car is in motion? Because if not....