Shockwave engine

[roost89]

I was sent a link to this. It talks about a "shockwave" engine.
The source was from NewScientist which goes into a bit more detail on how it works. Here's an excerpt:

As the rotor spins, the channels allow an air-fuel mixture to enter via central inlet ports. The mixture would escape through the outlet ports in the walls of the surrounding chamber, but by now the rotor has turned to a position where the channels are not pointing at the outlets.

The resulting sudden build-up of pressure in the chamber generates a shock wave that travels inwards, compressing the air-fuel mixture as it does so. Just before the wave reaches the central inlet ports, these too are shut off by the turning of the rotor.

The compressed mixture is then ignited. By this time the rotor's channels are pointing towards the outlet ports again, releasing the hot exhaust. As the gas escapes at high speed, it pushes against the blade-like ridges inside the rotor, keeping it spinning and generating electricity.

The video of the Professor talking about it.
[youtube]http://www.youtube.com/watch?v=uf_-IMgla34[/youtube]

I did some quick number crunching and got:
Roughly 80MPG (5x 15L/100km taken from a scan of this set of figures)
33.53 Horsepower for those who don't work in KW (25 Kilowatts)

So it seems like a fairly decent design. What do you guys think? Would it be a viable alternative to a current hybrid design?

[Ciro Pabón]

Wow. You do not see a new engine design every day (unless you happen to be a fan of our esteemed member, Feliks).

Thanks a lot, roost89, very nice video.

How did you reach those figures for HP?

[roost89]

no problem Ciro. I was surprised to see it too. I used Wolframalpha to get the converted number. It's a glorified calculator that's fairly powerful.

Since it's a hybrid what sort of losses would be associated with the power being transferred from kinetic to electrical and back to Kinetic?

[Richard]

Interesting!

[marekk]

A little more detailed description: https://docs.google.com/viewer?url=http ... .pdf&pli=1

Quite impressive idea. Not at Feliks level yet, but Herr Mueller is still young man.

[mep]

I am not convinced of it yet.
The process will only be optimal for one specific rounds per minute.
If it spins faster or slower the air/fuel mixture will either escape trough the exhaust or inlet or the optimal pressure will not be build up.
It's rpm range will be very limited that is for sure.

I also wonder how the thermodynamic cycle looks like. Changing that will improve the efficiency or not. I don't think the shockwave alone can build up a significant pressure/temperature compared to a ordinary engine. Reducing the weight of a engine doesn't impress me what we need is improved efficiency. Meaning that we need some better thermodynamic cycles.

[riff_raff]

roost89,

It's basically a detonation engine. The low NOx emissions and combustion efficiency are due to the combustion occurring under constant volume conditions.

The turbine engine companies like GE and Pratt&Whitney are working on pulse-detonation combustors using a similar principle. Piston engines likewise can use HCCI cycles which are somewhat similar.

It's interesting as a lab curiosity, but when scaled up it will have the typical problems with sealing, noise, heat transfer, controlability, and durability.

riff_raff

[Pdrive]

Firstly can I say that asking who had no points in an F1 season is a cruel question; Cruel to Bertrand Gachot that is.

I saw the shockwave engine in the New Scientist and wondered whether parts were missing. Looking at the parts in your article, obviously they haven’t been put in the real engine. Where are the stator blades?

Unfortunately for me I am not a qualified engineer, but I do know that to get good power from a gas turbine you have to have stator blade in between the compressor blades.

The shockwave engine is a type of centrifugal gas turbine and its rotor doubles up as a compressor. Put stator blades in the input and output chambers and you will get a more powerful and efficient engine. Shape the stator blades and you will do even better; and if you pay me to be on your development team you may do even better again.

As I said earlier in this comment, this is a type of gas turbine and gas turbines aren’t flexible; that’s why they aren’t used in motor vehicles.

Peter

[WhiteBlue]

roost89,
It's basically a detonation engine. The low NOx emissions and combustion efficiency are due to the combustion occurring under constant volume conditions.
The turbine engine companies like GE and Pratt&Whitney are working on pulse-detonation combustors using a similar principle. Piston engines likewise can use HCCI cycles which are somewhat similar.
It's interesting as a lab curiosity, but when scaled up it will have the typical problems with sealing, noise, heat transfer, controlability, and durability.
riff_raff

Pulse detonation engines and more precise pulse jet engines have been in use for a very long time. The most prominent example is the German "buzz bomb" cruize missile from WWII. I agree with riff_raff on the practical limitations of the design. On the other hand the sealing problems of Wankel engines must have been more severe and if there is a sufficient thermal efficiency in the design I can imagine such a light weight pulse detonation engine for a range extender in an electric vehicle.