New Engine Invention is 3.5X More Efficient Than Current Combustion Engines | Hacker News Reader

New Engine Invention is 3.5X More Efficient Than Current Combustion Engines

news.discovery.com

18 pointssalimmadjd12 comments

hope to have a car-sized 25-kilowatt version of the prototype ready by the end of the year.

This was posted last year. Any update?

Edit: well at least you can see it in action here: https://www.youtube.com/watch?v=nIPSTTvHfLs

Edit2: Just noticed it said "car-sized 25 kW" but that's only 33 horsepower. That's about half as much as a Smart car.

Assuming that the engine is both lighter and more efficient according to the article you might think that the horsepower numbers are going to be on a different scale compared to what we're used to. Old Geo Metros ran on 55HP and they used the "old inefficient engine".

Horsepower is power output. So the new engine might take a lot less fuel, but it still only puts out half as much power as a Smart car engine.

I'm not talking about power output. It's obvious that it puts out half as much power as a Smart Car. What I'm saying is that it might not matter.

I'm talking about necessary power output. If the engine cuts the weight of the car in half, then the scale of HP you're used to hearing applied to haul the car around in a desirable manner changes because you don't need as much.

I think the target market for this will be charging batteries in a hybrid car. So you get the low-end torque of an electric motor, and the ability to draw a lot of stored power for a short time from the battery, while keeping weight down (having a gasoline engine + an electric motor gets heavy) and radically reducing emissions.

> If the engine cuts the weight of the car in half

Then this engine has negative weight because current engines are much less half the weight of the car, let alone half the weight of the car plus typical load (which is the relevant weight).

Yes, an engine that weighs less means that you can have other parts that weigh less as well, but it's still not enough.

This is BS. Thermodynamics places a limit on engine efficiency at about 37%, the top of the line combustion engine is maybe 25% efficient. Thus an increase in efficiency of 3.5 times is BS. The only possible way to get the efficiency above 37% is to have the engine get super hot, ~>1500F. Which for obvious reasons is not practical

"As a result, the generator is 3.5 times more fuel efficient than typical combustion engines." It's talking about fuel efficiency, not thermal efficiency. Figuring in that the generator weighs a lot less and can make the car a lot smaller is probably where these numbers come in. The article could be a bit more specific about it, though.

> Figuring in that the generator weighs a lot less and can make the car a lot smaller is probably where these numbers come in.

The only relevant question is whether "the generator" is significantly more efficent than a conventional engine with the same power output, size, and weight. After all, we can make smaller conventional engines to put in smaller cars.

Disagree? Then I'll point out that there are micro-vehicles with conventional engines (albeit tiny ones) that do even better, thus "proving" that conventional engines are far superior....

This might be interesting.

Then again, I've read too many of these stories that turn out to be exaggeration, or the writer misunderstanding the real capabilities of the invention.

They are calling this a "Wave Disk Engine".

Here is a link to the wikipedia article http://en.wikipedia.org/wiki/Wave_disk_engine

This article is more than a year old, has there been any real followup?

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