hybrid biz plane

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craneplaneguy   10 kW

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hybrid biz plane

Post by craneplaneguy » Dec 13 2017 9:46am


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amberwolf   100 GW

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Re: hybrid biz plane

Post by amberwolf » Dec 13 2017 2:20pm

Not sure which article you meant to point to; when I click the link it comes up with an article about "Dumb And Dumber", a pilot ditching a plane.

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gogo   10 MW

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Re: hybrid biz plane

Post by gogo » Dec 13 2017 3:34pm

Trifan 600 VTOL

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Re: hybrid biz plane

Post by amberwolf » Dec 14 2017 12:52am


craneplaneguy   10 kW

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Re: hybrid biz plane

Post by craneplaneguy » Dec 14 2017 10:42pm

That's the one.

I'd be real interested to see how the entire concept of having a ICE, of any kind, drive a generator that powers an electric motor, pencils out, as compared to simply driving the fans directly. Of course diesel electric locomotives have been doing this for years, so there must be something to it. With an aircraft application, with an onboard battery that could even briefly power the aircraft if the ICE takes a hike, the safety aspect comes into play. The redundancy of having two sources of power may offset the added complexity?

dustNbone   10 kW

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Re: hybrid biz plane

Post by dustNbone » Dec 15 2017 12:51am

I could see a few potential advantages to a hybrid system in this application.

VTOL operations are notoriously power hungry during takeoff and somewhat during landing, being able to use stored energy in batteries in addition to the generator output might mean being able to use a smaller engine.

I'm assuming the combustion engine in this case is a gas turbine of some kind, they tend to run most efficiently at constant speed and high load, systems that allow them a wider range of operating conditions tend to add weight, complexity and cost. At cruise the hybrid system might allow the turbine to run intermittently at high load to recharge the batteries, and shut down while the batteries drain. It might even be able to close off the turbines inlet/exhaust ports during shutdown to improve aerodynamics.

I see cabin noise benefits as well, at least during the time the turbine isn't running. Not having the turbine mechanically linked to any propulsion system might also have benefits here, as well as giving flexibility in where the turbine is placed. This could also improve aerodynamics and cabin noise.

Also they could implement regen, recovering some of the substantial energy used to get the aircraft aloft. Those lift fans look like they could do a hell of a job of that provided there's enough battery capacity to eat it.

The problem I see is that many of these concepts violate the principle of safety/redundancy as a priority in aircraft design. I guess there are ways to engineer redundancies into some of them. Multiple isolated battery packs, maybe even powered by multiple small turbines. I guess that's what experts are for :)

I'd be interested to see how it would handle total electrical failure, is there some kind of auto rotate type system that would rotate the fans vertical and provide a survivable vertical landing speed? One of those giant airplane sized parachutes?

Anyways, very interesting concept. Thanks for posting.

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Re: hybrid biz plane

Post by Chalo » Dec 15 2017 1:24am

Vaporware for rich idiots.
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craneplaneguy   10 kW

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Re: hybrid biz plane

Post by craneplaneguy » Dec 16 2017 1:49pm

I've said it before, maybe here can't remember, but a hybrid power system like my PluginPrius has would be great in an airplane. Use all the e and ICE power for takeoff, once aloft and cruising, just the ICE, with resultant economy gains as it could be a lot smaller then if it had to handle 100% of the takeoff loads. If the ICE has a inflight problem....the remaining juice in the battery pack could serve as a range extender at the very least. I'm talking traditional fixed wing aircraft like I fly, something that flies without thrust, "real" aircraft fly dead stick. I've got the hybrid drive train, I've got the airplane, I've got the shop, I need to get busy and put them together! I put 1300 hours on a successful Subaru conversion in my last experimental plane, it couldn't be much more difficult then that? Actually it would, a lot, brighter minds then mine would be required. I believe hybrid power plant fixed wing aircraft will happen for real, no doubt first in the experimental/home built world, where all the innovation happens already .

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Chalo   100 GW

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Re: hybrid biz plane

Post by Chalo » Dec 18 2017 7:41pm

Hybrid propulsion is a tough case to make for aircraft. Every extra pound, every extra minute in the air, is costly. Airbus is looking at hybrid electric, but their effort us predicated on using superconductors and doesn't make sense without that element.

There have been aircraft diesels and they were fuel efficient compared to gasoline equivalents. But their extra weight nullified their efficiency advantage. In the same way, turboprops are less fuel efficient than reciprocating gasoline aero engines, but often more efficient overall because they're lighter and they enable higher speeds. The same goes for jet engines versus turboprops. They're thirsty, but because of their specific performance, they can result in the most economical flying overall.

Anyway, I strongly doubt that the added weight and points of failure intrinsic to hybrid electric propulsion will ever make sense for aircraft-- unless you assume the presence of superconductors, weightless batteries, or other things we don't have available.
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craneplaneguy   10 kW

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Re: hybrid biz plane

Post by craneplaneguy » Dec 19 2017 9:47am

I agree, just wishing! Lighter batteries or other means or storing the power is needed. But the basic concept makes sense to me, two power sources at takeoff, one in cruise. I experience this daily in the PluginPrius. Merging onto the interstate, which I'll do shortly, when I romp on it, kicking in the ICE plus the traction battery, it moves out damn smartly, as smartly as a gas guzzler SUV like most drive around here. Once up to 65 I hit cruise and get 50-60 MPG, while my SUV driving neighbors get 18 to 24 MPG. But yes, weight is a huge factor always, with aircraft, and just because it would work, to prove a point, doesn't mean it would be practical, at least with today's energy storage systems.

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