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Comment by samatman | Hacker News Reader

The HN headline for the article is terrible. The Wave Disk engine is a combustion engine, albiet one of novel design. It is a commonplace among engine designers that a combined turbine-electric system will be higher efficiency than a reciprocating engine is capable of; the Wave Disk appears to be a turbine engine with some slick combustion dynamics. That's great, but fuel is being combusted in any case.

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I apologize for that. This is pretty far from my area of expertice. I guess a more appropriate titled would be "more efficient than a traditional combustion engine".

Either way thanks for improving my understanding of the system.

"More efficient than an otto-cycle, reciprocating, piston-in-sleeve, internal combusion engine" probably would have put you over the title length limit anyway :)

Be fair. It's probably more efficient than Wankel engines too.

Wankel Rotary Engine! (at 1:07 of this clip)

http://www.youtube.com/watch?v=hTDUxaji6NI

Ach. You beat me to the Wankel reference.

I do feel like we've seen this movie before. The problem with rotary engines, usually, is that their round shape and operation, though efficient, can make sealing difficult. So they can be plagued by emissions issues when it comes to the wear-and-tear of everyday use.

But it would be sweet if this engine licked all of that.

Still, efficiency is good. It has been a lesser known fact that the standard multi piston engine model is hugely inefficient. Apparently this not only makes it more efficient fuel wise, but it makes it more efficient weight wise (20% less weight = 20% less energy wasted pushing it, not to mention cost and reliability)

> (20% less weight = 20% less energy wasted pushing it, not to mention cost and reliability)

Unless the weight of the competing engine is 20% of the weight of the car plus payload, reducing the weight of the engine can't get you to 20% less weight.

Also, cost and reliability don't necessarily go up as weight goes down.

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