Massive yet tiny

[The500man]

7iVlJGGhSfg#!

What do you guys think of this?

[BackPacker]

Lots of rambling and personal frustration going on. The fundamental design may be sound though, but the devil is in the details... Cooling, lubrication, ...

His comparison to the jet engine is wrong, I believe. A propellor-driven aircraft will not be able to reach a speed higher than approximately mach 0.6 due to mach tip effect. Unless a radical new propellor were to be designed that is efficient and quiet at supersonic speeds. A jet engine is good for at least mach 0.8. So the power-to-weight ratio is not the only reason for switching from propellors to jet engines. But he makes it look like this could potentially replace all the jet engines of the world.

[ShyTorque]

Yes, to develop that sort of power there is a huge amount of heat to be dissipated. It looks like conventional materials have been used with very low surface area. It's been tried before and failed as far as reliability was concerned.

I hope it works though. ;)

[XLC]

The concept was presented years ago and the inventor won the first prize for the design concept at the 2005 Emhart-NASA Tech Brief.
To me the personality issues are not important here (although in this case it has been a obstacle for the further development). More important is the fact that some people are thinking out of the box and sooner or later something that suits the context will be adopted. Those kind of projects (there are several) deserve much more input if we ever want to move on. Many ideas were thought to be impossible by many, not least the airplane.

[Ultranomad]

A propellor-driven aircraft will not be able to reach a speed higher than approximately mach 0.6 due to mach tip effect.
Tell it to the creators of Tu-95. It flew as fast as mach 0.74, and it was over 50 years ago. Later modifications are still in operation.

[BEagle]

The A400M has a maximum high-level cruise speed of M0.72!

[BackPacker]

Tell it to the creators of Tu-95

I have also heard that it was loud as hell due to the tips going supersonic. That might not have been important in Cold-War Russia, but things have changed since then.

[Ultranomad]

I have also heard that it was loud as hell due to the tips going supersonic.
It was indeed loud as hell, although at all speeds, regardless of sub- or supersonic flow. Just imagine eight 5.6 m propellers on four 15000 hp turbine engines.
By the way, there was a civil version as well, called Tu-114, used in 1958-1976 on long-haul international and domestic flights - not only by Aeroflot, but also by Japan Airlines. So, it was loud but not so loud as to preclude civil operation.

[Stephen Furner]

Wikipedia calls these swing piston or chasing piston engines, there is a quotation that "the swing-piston design combines all the disadvantages of the rotary with all the disadvantages of the reciprocating". Swing-piston engine - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Swing-piston_engine)

This HYT engine design is targeted at providing an alternative to large sophisticated muti-cylinder diesel engines. According to a quick search on the web there is also a history of groups working with this type of rotary design for small car engines. The e-mobile hybrid uses a rotary chasing pistons design that, as far as I can make out from the graphics, is a spark ignition that fires once a cycle. In the graphics of potential applications for the e-mobiles engine it includes light aircraft.

Russian Rotary Vane Engine - YouTube

[The500man]

Well with regards propeller efficiency, is the unit not small enough to drive a fan instead of the jet in a high-bypass turbo-fan engine? That might go some way to assist cooling as well. I've no idea about what the effects of high altitude might be on it, so there's a potential pitfull for commercial use.

That's a great video Stephen on how rotary vane engines actually work!

Another potential power plant could be the Energy Catalyzer (http://en.wikipedia.org/wiki/Energy_Catalyzer) which (supposedly) works by a Low-Energy Nuclear Reaction, although since it produces steam-power lugging around tons of water probably makes it inpractical for aviation.

[vihai]

Oh please, not here too, the E-Cat smells of a scam, looks like a scam and quacks like a scam...

[blueandwhite]

I don't see how they are expecting to seal the combustion chamber, or why he thinks it will be more efficent, and balence may be interesting.

[IO540]

Very interesting :ok:

Thanks for the post. (Next time pls use a descriptive subject ;) ).

I guess the Wankel-type tip sealing may be an issue, but Mazda more or less solved that, AFAIK. But they solved it on a watercooled engine; aircooled ones need looser tolerances.