Generated electric?

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 ?

The first thoughts I have is weight.

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.

RV8RIVETER said:

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.

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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.

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.

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

Norman CYYJ said:

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.

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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.

electric powered airplanes-

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)

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.

victor said:

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

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Except that it should be a RV-36.

Mike S said:

Except that it should be a RV-36.

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Makes no difference. By that point we'll have radar-guided autoland systems that make every landing a perfect 3-point.

DON'T PANIC! Gee gas is only double but available

RV8RIVETER said:

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 ?

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A self launched or winch launched glider? Its wind and solar powered!

Electric? Not even soon for cars. Right now electric cars are novelties and not on par with the fill'er up drive cross country of gas cars. May be 20 years for cars, but planes the weight/volume issues are greater. Hydrogen fuel cells are promising but cost, safety and infrastructure is an issue. Of course manufacturing hydrogen takes energy, electrical energy. The no free lunch rule.



When will the proverbial shizzle hit the fan? Probably 40 years, depending on many factors, may be 60 yrs, may be less than 40 yrs. In about 60-100 yrs (when I won't care) thing will be desperate fuel wise, if technology does not have suitable substitutes for fossil fuel. Home and cars I see many alternatives: Nuke, Solar, Wind, (hydrogen) fuel cells and who knows.

Planes? That is a different story, high energy density. Currently electric is not going to happen practically or large scale for plane due to battery technology. Can you imagine an electrical engine making 20,000 to 90,000 lbs of thrust a typical commercial jet engine produces. Even making 100 hp for extended periods is not likely to be practical anytime soon, may be ever?

100LL (really 95UL is the future) will be avaiable through out our life and our kids (may be), its just a matter of cost. Don't panic. A RV flown prudently can get into the 30 mpg, easily 25 mpg. Not super when compared to a super econ-O-box car but not far off. An sub compact car of course does not do the better part of 200 mph.

Bottom line our hobby just got way more expensive. Gas will be avaiable, just a matter of if you can afford it. Really we'll be looking back on the $100/barrel days as the GOOD OL DAYS. Actually its already at $120/barrel. So the good ol days was just last month.

Electric motor driven by a solar t62 and light weight alternator unit. Should be easy to get 100KW out of such a unit.

Actually, this is perhaps a better use of the solar t62 (or whatever model they are using) turbine than what Innodyne is trying.

I pray they can deliver a 300 HP turbine that sips diesel... but know better.

This could be done, but right now might be too heavy to get off the ground. Heck, if your running a turbine to generate electricity might as well ditch the electric motor and use the turbine to drive the prop -- Same fuel burn.

Nevermind. Reality has set in and I need to get back to writing my investment check to Innodyne

DR

If you figure out call me, I have money to invest

Roddzilla said:

Electric motor driven by a solar t62 and light weight alternator unit. Should be easy to get 100KW out of such a unit.

Actually, this is perhaps a better use of the solar t62 (or whatever model they are using) turbine than what Innodyne is trying.

I pray they can deliver a 300 HP turbine that sips diesel... but know better.

This could be done, but right now might be too heavy to get off the ground. Heck, if your running a turbine to generate electricity might as well ditch the electric motor and use the turbine to drive the prop -- Same fuel burn.

Nevermind. Reality has set in and I need to get back to writing my investment check to Innodyne

DR

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Turbines do sip diesel and actually kerosene or even gas. The problem is turbines are NOT fuel efficient. Powerful, light, compact, reliable and capable of making huge power, but the specific fuel consumption per HP is much higher than a piston engine in the 300HP range or any range. Of course piston engines above a certain size say more than 600-2000 hp is not practical with a piston engine, and turbines rule in the weight to power ratio. Still fuel economy is not a selling point of turbines.

I think you ran around the logic circle on your own. A turbine for a small GA plane is not likely to ever meet the SFC of a piston engine. If we could only improve thermal dynamic efficiency. As you know gasoline engines are only 37% efficient (even with turbos), meaning they throw away 63% in heat. So if you could double efficiency that would be great. If any of you figure out how please call me or write me, I have some money to invest.

PS: As far as Innodyne its not a turbine its a toy, a single stage that is not even efficient for a turbine. You might know they are defunct (again). A poor fellow RV-8 bother had one, it toasted. He sent it back but in the aftermath of the business failing, they have not returned his engine, which was bought and paid for!

To get a little off topic, if we would junk most of the big trucks, SUV's for personal 50 mpg vehicles (not even hybrid) we'd solve the short term gas issues and get of foreign oil. Of course attrition would need to take over but car makers still make vehicles with 18 to 25 mpg on a good day. Think about it. The current average car / light truck on us highways and roads in the USA gets 17 miles/gal! Today's average reg gas price is $3.60/gal. Even if the average gas milage of vehicles only went up to 35 mpg we, could get off of mid east (mostly). As far as gas prices, I think (know) the US & foreign oil companies and Oil cartels are capitalizing on circumstances. Supply and demand issues are more complicated because of the world wide demand from burgoning economies like China. However if we cut use in half the price would fall. Sadly my wish or theory is not likely to happen. I'm no tree hugger but we have to get real. Pain now or pain later. Future of GA?

There was local news paper article of a guy about his Bonanza and his Son who is also a pilot. They are selling the plane and will stop flying. That is sad.

Yup

I do understand the engineering behind all of this... I meant "sip" as in barely use any. I know Innodyns claims are extraordinary. Maybe the sarcasm (towards Innodyn) in my post was not amplified enough.



Thanks though.

DR

Oil shortage is a scam

There are people looking very seriously at electric flight. Just down the road from me Bertrand Piccard has the Solar Impulse project (http://www.solarimpulse.com/)

Nice

Thanks to all, nice open discussion, just what forums are for.

I thought it would be fun to just throw out this topic and see what happens.

Yes energy is lost conversion but it makes a lot more sense in cars, where the generator engine can be tuned for one most efficient rpm and not expected to power 100% output as capacitors or batteries can make up the difference for acceleration. Cars also stop/start so the wasted energy on stopping can be reclaimed.

None of those really apply to an airplane, so we will have to wait for some revolutionary battery technology.

One aspect of this topic that wasn?t considered is the ability of a hybrid system to ?bank? or temporarily store power to be used in addition to the internal combustion engine output. Although we think of an airplane engine being used for somewhat constant power output compared to an automobile engine, it really isn?t. An example mission of an airplane may be to takeoff at a specific load requiring 200 HP. Once at cruise the engine would be throttled back to 65% power at which time that remaining 35% power capacity is not needed and really becomes a lump of aluminum ballast. A similar mission could be accomplished with a hybrid system incorporating a 150 HP engine and enough energy storage capacity for an additional 50 HP for say 10 minutes. Prior to takeoff you would be running your engine at full power to top off the batteries and once completed you could generate your required 200 HP (for about 10 minutes) needed for takeoff. Once in cruise mode, the engine would run at full power although only 130 HP would be needed to maintain cruise speed, the other 20 could be used to top off the batteries so you would have your 200 HP available if needed. This is just an example, the system efficiencies and weight would all have to be worked out of course for this to really be feasible along with the risk factors of not always having full power available at your demand but I think the system could be workable. Sort of like a re-usable self recharging JATO system.

You all remember the NASA flying elec wing (unmanned)

Remember "Helios" that hugh flying wing, unmanned solar plane, for high altitude research.
LOOK AT THE FLEX OF THE WING!

http://www.youtube.com/watch?v=5oNHD41MLMk

Its no more and broke-up in flight, into ocean, Hawaii in 2003.

http://www.cbc.ca/health/story/2003/06/27/helios030627.html

At this time with solar cell power and elect motors this is what it takes. So the motor and cell technology would have to be much advance to fly on sun power only. Also cost?

Hey Guys,
Electric power may be available sooner than anyone thinks. Check out A123 Systems, they developed the batteries for the upcoming Chevy Volt (2010), built an electric drag bike...fastest on record....appears to have good potential but I really like the sound of internal combustion.

Glenn Wilkinson

glenn654 said:

Hey Guys,
Electric power may be available sooner than anyone thinks. Check out A123 Systems, they developed the batteries for the upcoming Chevy Volt (2010), built an electric drag bike...fastest on record....appears to have good potential but I really like the sound of internal combustion.

Glenn Wilkinson

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Yes, batteries are getting better. In addition to A123, AltairNano is providing batteries to Phoenix Motorcars (who have begun production of an all-electric pickup truck for fleet use in CA).

Better still, if they actually deliver, is EEStor (about double the energy storage per pound of either of the above batteries). However, I ran some calculations based on everyone's published numbers. To replace 40 gallons of gas with EEStors' unit would be around 1,200 lbs just for the battery compared to 240 lbs of gas. The best available LiIon batteries would be nearly twice that (around 2,000 lbs for AltairNano or A123).

Cars are an easier sell. With regenerative braking to recoup some of the power lost while driving, it is "reasonable" to have only a 10 gallon tank equivalent (300lbs for EEStor; 550 lbs for batteries). Some of the weight difference is also offset by all of the things you DON'T need with an all-electric setup (e.g. alternator; cooling; and with wheel motors you can eliminate engine and transmission). Since cars only use around 10% of their maximum rated horsepower in cruise, they don't need huge amounts of stored power. Aircraft, however, operate at close to 100% power 100% of the time, so until we can be happy with one hour flights it will be a while yet until electric planes are the norm.

Here's a crazy thought to throw into the mix...

What if a couple of wind generator's were attached under the leading edge of each wing? Could these be connected to an alternator that produced enough power to supplement the battery charge and extend the life of a battery discharge?

This would not work: The Thermodynamics cops would pull you over and give you a ticket for breaking the first law.

The Solution Is...

The solution is:

An Arc Reactor. I just saw it in Ironman: About the size of your fist, and baby does it put out the power!

pmccoy said:

Here's a crazy thought to throw into the mix...

What if a couple of wind generator's were attached under the leading edge of each wing? Could these be connected to an alternator that produced enough power to supplement the battery charge and extend the life of a battery discharge?

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As what DTaylor said, however you could cover your plane with solar panels and not break the laws of physics. Of course thier effeciency isn't very high either.

The nagging problem isn't energy, its the storage of the energy. Gasoline happens to store a lot of energy in a small space in a simple and light container. Hydrogen, electricity, compressed air, nuclear, cng, and others can't do that yet.

Now if we could get a flux capacitor, a lightning rod, and fly a little closer to thunderstorms...

Shockwave said:

As what DTaylor said, however you could cover your plane with solar panels and not break the laws of physics. Of course thier effeciency isn't very high either.

The nagging problem isn't energy, its the storage of the energy. Gasoline happens to store a lot of energy in a small space in a simple and light container. Hydrogen, electricity, compressed air, nuclear, cng, and others can't do that yet.

Now if we could get a flux capacitor, a lightning rod, and fly a little closer to thunderstorms...

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Nuclear, not so much. One pound of enriched uranium which is about the size of a golf ball contains the same amount of energy as a one square block 13 story high apartment building filled with oil. It also makes a pretty good bomb.

SuperSixOne said:

Nuclear, not so much. One pound of enriched uranium which is about the size of a golf ball contains the same amount of energy as a one square block 13 story high apartment building filled with oil. It also makes a pretty good bomb.

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Might make a bomb-------if refined correctly, and correctly installed into a rather complex mechanism, and a few other things that must be done correctly, and deliberately.

At least the "golf ball" (minus above mentioned support staff) wont catch fire in a crash like the petroleum products will.

Water Power?

All this talk about alternative fuels made me think of the following clips that I had seen.

Personally, I am not a big fan of electric stuff. It just doesn't seem like it will ever be meant for moving large objects around. But never say never right?

There is a bunch of stuff on youtube about water power that I think are very fascinating.

Here are a couple interesting clips. The problem that I can think of as it relates to aviation would be the radio frequency with this water power.
http://www.youtube.com/watch?v=JiKa4nOkHLw

This one, I am not sure if it is real. But worth a look. Let's hear what y'all think. There are probably hundreds of other clips similar to this one. only not news stories.
http://www.youtube.com/watch?v=CMovXzVOzc4

Good to be here by the way.

FAA Regs - Remaining fuel time.

Don't forget to have your 30 minutes of fuel on VFR or 45 on IFR flights - I guess the same would hold true for a battery.

Self serve pumps would be interesting too. Based on how long it takes to charge a battery, heck....we'll be here all night.

Don't know about you but my flight instructor was anal about having a spare set of batteries in the brain bag just in case. Now I'm going to get a hernia to carry it.

I think I'm going to call Scotty and see if Captain Kirk will loan me some dilithium crystals (or whatever they called them).

Why do we think fuel is expensive - the guy who has a nice boat gets about 3 miles to the gallon at the same price and bottom line cost of the fish he brings home is about $200 a pound for that fresh fish dinner. Makes our $100 hamburger seem like a deal and we didn't have to cook it either.