remove the alternator and installing it on the front of the car

[Frank Lee]

How big a prop(s) would be needed to work there?

Smokey Yunick did the same thing on a race car but for a different reason: he was having a problem throwing belts. And of course going well over 100 mph he had a lot of wind to work with and also low current draw on a race car.

[Bicycle Bob]

If you look up the story of the "Gimli Glider" the auxiliary power turbine is mentioned there.

In general, the motor is the best place to get power for a generator. However, there might be opportunities for one flapping in the wake, where things are already messed up and energized. I'm not advocating dragging a prop in the turbulence, but rather extracting energy from the sideways component of it. However, the space is probably better used for a long tail.

[noeryan]

Thank you Bicycle Bob! I've never seen those before. I wouldn't put a large turbine in front of the radiator and you wouldn't get much out of it but it would be something for nothing ya know?

[noeryan]

I'm addicted to this site haha. I was driving to school and remembered a MATLAB program I had written to calculate the best curvature of a turbine blade I was designing last summer.

If anyone is serious about trying to implement a turbine in front of the radiator let me know.

To ball park some figures of the power available in the oncoming air of an area 1 foot by 3 foot (3 sq. feet) guestimate...

Kinetic Energy -> E = .5mv^2 ...:: m = mass , v = velocity

Mass Flow Rate -> m/s = (rho)Av ...:: s = second , rho = density , A = area

Plug in Mass Flow Rate into Kinetic Energy for m:

E/s = (.5(rho)Av^3)/s = Power ...:: Energy per second is power.

**All following calculations are at sea level and converted to SI Units**

So 10 mph -> P = .5*(1.225)*.28*(4.48^3) = 15.4 Watts possible

30 mph -> P = .5*(1.225)*.28*(13.41^3) = 413.6 Watts possible

55 mph -> P = ...................*(24.59^3) = 2.55 kW possible

70 mph -> P = ...................*(31.29^3) = 5.25 kW possible

Pretty big jump. Lets be real and say we could get 10% of that... Catching 255 watts driving 55 mph at night might cover the headlights. Might be something worth trying. Like I said, let me know if you want me to run the AoA program and give you the curvature of the blades. I'll need a ballpark figure for how fast you want it to spool up and the alternator's efficiency so I know what kind of force is needed at that speed.

-Ryan

[mfor4x4]

I realize that this is more than likely many years ahead of current technology but are there any electrical generators that generate electricity from sound energy? There would be great amounts of energy that could could be created from a car just going down the road with all the noise from the tires.

Imagine a city could generate electricity just from people doing their day to day activities.

What about generators in the struts?

[Frank Lee]

What about generators in the struts?

Somebody has done that~

[noeryan]

I had an idea for a muffler that was pan shaped that sat in the exhaust of the car and used the engine's pulsing exhaust to vibrate the mechanism and produce electricity, it would also muffle the engine. I never ran any numbers to see what could be obtained. I think I might thanks for the reminder!

But to answer the question on road noise energy? I don't believe the pressure gradient would be great enough to harness much of it. IMO not enough power to be harvested.

[ChrstphrR]

Originally Posted by mfor4x4

I realize that this is more than likely many years ahead of current technology but are there any electrical generators that generate electricity from sound energy? There would be great amounts of energy that could could be created from a car just going down the road with all the noise from the tires.

Actually, there isn't great amounts of energy to be had that way. ALL the sound energy produced during the entire Superbowl in Tampa was enough to heat up a cup of coffee.

[modmonster]

Originally Posted by Frank Lee

What about generators in the struts?

Somebody has done that~

do you mean the shocks or dampeners? there is energy there

[SuperTrooper]

Originally Posted by noeryan

Could you send me a link to the aircraft 'drop down turbine'? I've never heard of an aircraft dropping a turbine to gain power for control incase of an engine failure. I know the larger aircraft have an aux. turbine but it is run off of fuel, not air.

Here you go:

Electric Systems

Note the Emergency Ram Air Turbine to the right of the pic.