humber:
I mention the maximum power theorem,
I'm an electrical engineer, and that's an electrical engineering term. wikipedia agrees:
http://en.wikipedia.org/wiki/Maximum_power_theorem
In EE, all it means is that if you have an amplifier with an internal resistance of 4 ohms, then if you want to transfer maximum power to the load, it should be 4 ohms too.
Do you have a URL to the Maximum power theorem you're talking about?
Also, out of curiosity, what do you do for a living?
I don't know. Too complicated and a lot of guessing? Power is not measured like that.
Huh? Power is work per time. Work is force times distance.
Power (watts)=force(newtons) * distance(meters) / time (seconds)
If you can extract 10 watts of power from a windmill, you can lift 1 kg at 1 vertical meters per second, or half a Kg at 2 m/s, or 2 kg at one-half m/s or whatever, it's all 10 watts.
Oh, and I thought of a better electro-generator cart design.
take a cart, attach a tower with a propeller on top. have the shaft of the prop drive the shaft of a generator. have the casing of the generator sit on it's own set of bearings too. The casing will be connected via a gearbox to the rear axle. The rear axle will spin the outer casing of the generator. The propeller will spin the center shaft of the generator. say we use gearboxes and propeller pitches so that 1 mph translates into 100 rpm rotation, for the prop shaft or the generator casing.
Now, with the cart standing still, in a 10 mph tailwind, the wheels are stationary and so the casing is stationary. The propeller feels a 10 mph wind, so it spins at 1000 rpm. The case is stationary.
The electrical generator is rated to put out 12 watts of power at 1000 rpm.
So take the 12 watts and put it into a motor driving the front tire, this starts accelerating the car to 1 mph.
At 1 mph, the prop feels 9 mph of wind so it spins at 900 rpm. But the cart has a ground speed of 1 mph, so the back wheel spins the generator casing at 100 rpm. The rpm of the shaft compared to the casing is 1000 rpm. so, 24 watts, so continue acclerating.
when the cart is moving at 10 mph, the prop doesn't feel any wind, so the shaft of the generator isn't moving compared to the cart. but the wheels of the cart are turning at 10 mph, turning the generator casing at 1000 rpm, so 24 watts, so continue accelerating.
The generator puts out some amount of power based on the RPM between the shaft and casing of teh generator. Normally, the casing is stationary, and you just have to deal with the RPM of the prop. But if we mount the casing of the prop to the body of the cart, the generator won't put out power when the cart is moving at windspeed.
By making the tires turn the casing, and by making the prop-mph-to-shaft-rpm the same as the wheel-mph-to-casing-rpm, we're guaranteed that the propeller to shaft RPM is always constant, regardless of the speed of the cart compared to the wind. The only thing that matters is the speed of teh wind compared to the ground, and the size of the prop which determins how much power you can actually convert per mph.
Well, they contribute to negative drag, and must be something to do with molecules or sub-atomic particle physics. I wonder if they're negative dragons.
Ignoring, of course, the little detail that cavitation can't occur in air.
