New petrol engine design 4x efficiency of pistons?

[marchesarosa]

New gasoline engine design has 4x efficiency of pistons
Posted on April 11, 2011 by Anthony Watts

This looks promising. It is basically a continuous combustion wave turbine. While not super powerful in this early design and not intended to replace a V-8 it can be brought to market for a hybrid vehicle application soon, according to the researcher. See the video below.




While they’ve got a focus on CO2 for the usual reasons, I’ll take increased efficiency any day.



Schematic model of a wave disk engine, showing combustion and shockwaves within the channels. Source: Michigan State University.

Researchers from Michigan State University have been awarded $2.5 million from the Department of Energy’s ARPA-E program to complete its prototype development of a new gasoline-fueled wave disc engine and electricity generator that promises to be five times more efficient than traditional auto engines in electricity production, 20% lighter, and 30% cheaper to manufacture.

more here
wattsupwiththat.com/2011/04/11/new-gasoline-engine-design-has-4x-efficiency-of-pistons/

[jonjel]

Not so very new Marchesa.

Gaede came up with a similar device in the 30's, as a vacuum pump design. The only difference is expanding gas drives the model you show, while a motor drove compressing gas in his.

Interesting, but I doubt the countless billions invested in ICE's will be impressed.

[carnyx]

jonjel,

... not having followed up WUWT, I wonder whether the shock-wave is the critical element. Did Gaede's compressor utilise it?

Anyway, I suspect that gas sealing may be the problem, especially in the presence of shockwaves, as it was with the Wankel engine.

[jonjel]

Correct Carnyx. Sealing is the problem, and for Gaedes design (still widely used today) to work properly the machined parts have to be made to very tight tolerances, and set to tight tolerances.

I think the by-products of combustion might do for this one, but new or modified ideas are always worth a look so I am not slagging it off.

[principled]

Jonjel
Eons ago when a young student I remember acquiring a book(i think it's still in my loft) that classified rotating machines. It was then that I realised that there was no configuration of machine (whether engine, pump, or compressor) that had not already been thought of.

In terms of rotating engines, Felix Wankel spent a large part of his life trying to perfect a truly rotating engine, after apparently having as dream at the age of 17 about such an engine (see link) . The achilles heel with all the designs- as you pointed out- is sealing the chambers (side and tip seals). Something Wankel struggled with, but now largely overcome with modern materials..
www.mazda.com/mazdaspirit/rotary/story/index.html

There is little detail to go on in the press release for this new engine, but the shock wave element would lead me to suspect a limited rotational speed range, which may well be ideal for recharging on hybrids rather than a stand-alone power source. Indeed, the statement that this engine:

The WDG also can reduce carbon dioxide emissions by as much as 95 percent in comparison to modern internal combustion vehicle engines.

can only be true if it is a hybrid.

P

[jonjel]

You are spot on there Principled. New design as such is rare and we only really have improvement in what went before. And modern materials do play a very big part.

If one takes another 'invention' the bouncing bomb, that was not new either. Barnes Wallis improved on a method used by Nelson who discovered that you could skim cannon balls off a reasonably flat sea to devastating effect. No doubt children had skimmed stones for millennia before Nelson.

As an aside, when Barnes Wallis was a very old man and I was a very young engineer I met him. He had an office on the old Brooklands site. And his brain was as active as it had ever been.

[nickcosmosonde]

Hasn't it been shown now that the old conundrum of how bees manage to fly despite their lacking the necessary musculature is thanks to the circularly rotating impetus from such repetitive timed shock-waves? The same effect is utilised by birds in adopting the classic V-formation in group flight.

I was amazed to learn in the recent doc about Barnes Wallis' bomb that the Germans were developing exactly the same device at the same time. I don't know where they were planning on using it - against Russian dams, perhaps.

[jonjel]

The same effect is utilised by birds in adopting the classic V-formation in group flight.

I thought that was all to do with minimising drag? Similar to a peloton in cycling, you take turns in being the leader.

[nickcosmosonde]

I think that was for long the accepted explanation, sort of. The "sort of" relating to the precise meaning of "minimising drag". You're referring to air resistance, I think, judging by your cycling analogy. But I don't think that accounts for the V-flight of birds. As far as I understand it, the theoretical understanding of the advantage there is not due to minimisation of air resistance, but the uplift given to the trailing birds from the shock wave of the beats of the leading birds' wings. I may be wrong - but I'm pretty sure I read that not too long ago.

[principled]

Hi Nick
Your post prompted me to read further as, like Jonjel, I had always assumed the cycling analogy (viz lower air resistance ) to be the reason for that formation. It would seem that we live and learn as this Wiki link shows.
en.wikipedia.org/wiki/V_formation

Your description is also quite timely as the Canada Geese are returning to the central plains of Canada at the moment and everyday I see large "V" formations of them. So I can now impress others with my profound knowledge of the reason they fly in that format!

[jonjel]

Well, you learn something new every day. And long may that continue on this board.

I suppose to get maximum benefit the geese would have to synchronise wing beats, but not in time with the one they are following.

And I am sure quite recently I heard an 'expert' explaining that birds migrate in Vee formation to reduce drag. When I next hear that I can shout 'pillock' at the TV or radio!

[nickcosmosonde]

I suppose flight in V-formation does reduce drag, so to speak, in that the effort required in maintaining height by the downward beat of the wings is less strenuous if you're riding these pockets of shock-waves. I seem to recall I read about this refinement in analysis of the matter in a small article in Scientific American about...four years ago, maybe five.

[StuartG]

How is the disk engine started? Does it run at a fixed speed? What cools it?