Generated electric?

[RV8RIVETER]

The new engine thread in the discussion section got me thinking about future power options. The thoughts about future aviation also give some pause with the future of 100LL probably in doubt. And with China and India in the process of of rapidly expanding there automobile population who knows where the price of gas is going.

For a future engine, my thoughts are turning to gas/jet generator to power electric motor, ie series hybrid if you want to use the auto term.

Anybody else have any thoughts ?

[Mel]

The first thoughts I have is weight.

[RV8RIVETER]

The Tesla roadster lists its 185kW motor at 70 lbs and the engine and transmission combined at 110lbs. For an A/C you might be able to shed the transmission, so that would leave approx 220 lbs left over (comparing to io-360) for the generator and accessories.

[RVbySDI]

Originally Posted by RV8RIVETER

The Tesla roadster lists its 185kW motor at 70 lbs and the engine and transmission combined at 110lbs. For an A/C you might be able to shed the transmission, so that would leave approx 220 lbs left over (comparing to io-360) for the generator and accessories.

Well that might be an accurate examination of the actual motor that will be spinning a prop but the original post was looking at a gas powered generator to drive that motor.

This is where the weight comes in. Not only do we have to look at the weight of the electric motor but now we have to look at the weight of the gas powered generator that will supply electricity to that motor. So can we provide an adequate generator within the specific weight limits to make it work?

I think electric motors are the real powerhouses in the engine/motor world. They provide maximum torque throughout their complete RPM range. They are close to 98-100% efficient when transferring energy to motion. There are a lot of benefits to running electric motors. However, the real hurdle indeed is weight. Oh, not the weight of the actual electric motor but the weight of the mechanism(s) needed to provide the flow of electrons to that motor that allow it to do its work.

The true obstacle to running electric motors is the ability to feed the motor the electricity it needs to do its job. This is true whether you are carrying around a generator and whatever fuel source it needs, batteries, fuel cells or even spinning flywheels. Each source has its own set of issues to deal with and with every one of them, weight is one of those important issues to overcome.

[Norman CYYJ]

My first thoughts on the idea were that every time that you convert from one form of energy to another you loose energy and the weight factor.

[jsharkey]

Check out Sonex's electric motor web page. It's the way of the future.

http://www.youtube.com/watch?v=P8Pb_psj1A8

Jim Sharkey

[skyflies]

Originally Posted by Norman CYYJ

My first thoughts on the idea were that every time that you convert from one form of energy to another you loose energy and the weight factor.

Exactly. There is a loss whenever energy is converted from one form to the other. Unless the benefit of the downstream form far outweighs the loss, it doesn't make sense.

Electric motors are used in diesel powered locomotives because of their torque and ease of speed control. If someone figured out an automatic clutch for those locomotives, the diesel engine itself would be the most energy efficient solution.

[victor]

Electric motors would be perfect for airplanes. The problem would be getting the power to power them. Todays batteries are limited in capacity and too
heavy for practical use even in cars, much less so in aviation. The technology in batteries is evolving, and this might change drastically at any time. Needs to be lightweight, high capacity, and quick charge.

A generator to power a motor(Tesla- 185kw) would require a gas, diesel or turbine engine, probably liquid cooled, plus the fuel to power same. Same problem, the weight. (We are talking more than 150hp generator)

I can envision in possibly 25 years most of these problems being solved.
Maybe having power beamed up from ground stations by laser beams or microwave, or better yet, directly from the sun.(by then we will have our own fusion module powering our electric twin-motor RV36-A's)

[Norman CYYJ]

For initial training and just doing circuits electric planes would be great. Just run a long extension cord from them. Plug them into the top of the tower to keep the cords off the ground so people wouldn't be tripping over them with their feet or the others in planes with real aircraft engines that make noise. It would be a bummer if the cord got caught in the prop like the extension cord on your electric lawn mower.

[Mike S]

Originally Posted by victor

(by then we will have our own fusion module powering our electric twin-motor RV36-A's)

Except that it should be a RV-36.