Interesting engine concept.

[shakescreek]

http://www.dieselair.com/2012/01/we-have-found-breakthrough-in-diesel.html
http://www.fairdiesel.co.uk/p1.htm

Came across this and thought it looked like an interesting concept. Claims some impressive #s for bsfc and power to weight, probably to good to be true. Would like to hear what some of the experts on here think. Meister?

 

[TDIMeister]

Take the first word of your username, replace "h" with "n" and change -creek with -oil.

Edit: It's a swashplate engine, yet another of many proposed over decades. I bet their efficiency and power output analyses were done using the air-standard cycle. Nothing ever comes out of them because of the lubrication mode that's is required between the connection from the pistons to the swashplate. Each power stroke is like a jackhammer impact on that swashplate. Engine won't last worth a crap or we'd be driving with engines using them now. Swashplate mechanisms were first introduced for steam engines in the 1800s, maybe even earlier.

http://en.wikipedia.org/wiki/Axial_engine
http://www.aqpl43.dsl.pipex.com/MUSEUM/POWER/axialsteameng/axialsteameng.htm
http://www.aqpl43.dsl.pipex.com/MUSEUM/POWER/unusualICeng/axial-ICeng/axial-IC.htm
http://www.aqpl43.dsl.pipex.com/MUSEUM/POWER/unusualICeng/cam-IC/cam-IC.htm

 

[Powder Hound]

The low end of the bfsc numbers have been achieved, notably by the Junkers Jumo engine mentioned in the Fairdiesel website. VW's bfsc number for the ALH engine, IIRC, was optimally about .26 pounds / hp-hr. To me, it is the power to weight number that seems difficult.

But not to worry. They might attract enough investment capital to keep looking for more investment capital, but they'll never get into series production. Even if they could get the engine done (I don't think they can), I bet they'd never have enough money to get JAMA and FAA approvals for the engines to be able to sell them to airframe manufacturers. The existing walls are just too high to get over.

 

[TDIMeister]

The low end of the bfsc numbers have been achieved, notably by the Junkers Jumo engine mentioned in the Fairdiesel website. VW's bfsc number for the ALH engine, IIRC, was optimally about .26 pounds / hp-hr. To me, it is the power to weight number that seems difficult.

The VW TDI best-point BSFC is 196 g/kWh (0.322 lb/HPhr). The claimed 0.22 lb/HPhr would equate to 134 g/kWh or a brake thermal efficiency of about 63%. This has never been creditably achieved by an ANY internal combustion engine before, nowhere even close by the Junkers Jumo or Sulzer RTA-96C, currently the most efficient engine in the world at around 0.26 lb/HPhr (54% BTE).

I agree completely on the capital attracting more capital thing though.

 

[Powder Hound]

.322? Hmm... I guess my memory is worse than I thought. Seems I remember a bfsc pretty colored chart for the 1.9 TDI that showed a sweet spot hump that peaked at .26. I must be mistaken. Too bad - it would be fun to get that kind of efficiency out of them.

And for the Sulzer engine - you should be able to max it out with a monster like that. I wonder how they compare with electric generating power plant steam turbines in terms of efficiency?

 

[Pat Dolan]

All of the above, PLUS: what really burns my butt is that there IS an engine with fantastic potential as an aircraft diesel - the Wankel. Pipe dreams such as this are just one more thing standing between good science and engineering and capital markets.

 

[MrMopar]

All of the above, PLUS: what really burns my butt is that there IS an engine with fantastic potential as an aircraft diesel - the Wankel. Pipe dreams such as this are just one more thing standing between good science and engineering and capital markets.

You say "diesel Wankel [engine]" in one sentence, and then say "good . . . engineering" in the next sentence. Those two concepts don't go anywhere near each other. Wankel engines have horrible seal problems that Mazda was only able to overcome in a GASOLINE engine after 25+ years of experimenting with customers functioning as beta testers. I was one of those RX-7 owners.

Ramp up compression ratios to diesel levels and you will find out how short a lifespan a Wankel engine can have before requiring a rebuild. I predict it will be measured in single-digit hours, maybe even minutes . . .