rotary emotions

Yes, but there not "real" diesels. I'm not really sure how they work, but they do differ from what you'd call a self-combustion engine somehow. But now you say, I should take a look at them! Point is: you can add compression by blowers and/or turbos, but I feel that's making the setup more complicated. I'd like to know if a "simple" DKM would be possible. Anyway, I kinda like this discussion. It's great to think about what could be done with the original design of Felix Wankel...

nimrodTT

If it was a single rotor design, the spark problem is easily fixed. I'd be concerned with cooling and sealing problems.

That link to the page about his original design didn't work for me.

inittab

BTW, the German site translates very nicely with Google's language translation tool. Gotta love the picture of Felix's personal 4 rotor Mercedes, how cool is that?

onepointone

if they were to use diesel, would that greatly shorten apex seal life?

im becoming interested in mercedes design, i knew they made one, but never looked it up.. im doing so now

rotary emotions

Rolls Royce did a Wankel-Diesel, using two rotors/housings in one casing. It comes down to the big rotor being a pump, an the small one the engine. The pump does just the same as a blower. Apex seals should be something that can be managed, I think. There just never was much research into this subject. All companies based their research on the KKM. And since about 20 years there was'nt that much research at all. Only Mazda and some specialists went on.

fatboy7

It seems to me that the problem with chatter would be significantly less... the apex seals aren't moving in and out, just around and around. The chatter in the KKM comes from the orbital motion. Thats one reason why the prototype reved to around 28,000 rpm with no problems.

And about the high frequency idea, you wouldn't have a problem with the rotor intermittantly acting as an electrode, because the energy wouldn't beable to escape the combustion chamber. In reality, some energy could escape where the seals aren't perfect, but after coming in that close of proximity with the metal surfaces, there couldn't be enough energy to excede the break down voltage of the fuel and/or air anywhere in the other chambers.
The difficulty of this type of ignition would be more related to delivery, than to problems in the combustion chamber.

Microwave ovens are designed so that very little energy comes back into the microwave producing elements. Old microwaves couldn't handle metal in the slightest, because the reflected energy would quickly blow the microwave. Today it is much better, you could actuly put a pot(w food of course) in the microwave. That would be one major problem with this system. With nothing to absorb the energy but the air/fuel, almost all the energy could/would be reflected. It doesn't take much to start combustion, but requires huge electric fields to cause the initial sparking action. Designing around this issue I think is the biggest hang up, well that and there is no way that FCC would like it...

rotary emotions

The rotor and housing have the same shape as in the KKM, so normally the chatter mark problem would be about the same. The problem is that the leaning angle of the apex seals against the housing changes constantly, therefor causing the seal to "jump", and create marks. However, these problems are largely overcome by now. The engineering of a DKM should be relatively simple (well, what's simple?) using the common KKM technology. But no big firm is gonna do it. Let's say Mazda would try: they would have to forget about all these years of developing the KKM... So huge costs, for small increasements in power. And the ignition problem remains. Although you could try to put the plugs in the side housings, facing inwards. Not sure if it would work, but it might. Can't build anything larger then a 2-rotor,though. With a single rotor design you could try a four-plug setup, 2 in each sidehousing. Well, I guess it would be a real problem, since it would mean sealing between side and rotorhousings...
Or you get the side housings to turn aswell, and mount them to the rotorhousings. You can mount the coils on there and have them turning aswell. All that has to be transferred is the impuls to fire the coils.
I'm gonna spend some time thinking about this in the weekend, this is getting real fun. Better then a jigsaw :-)

rotary emotions

Innitab,
I saw the rotary SL in Lindau, last month. It is a lovely car. I'm going to make a simular "WANKEL"-emblem for my car, if I can manage that...