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Similar design has been in development by the StarRotor Corporation. Will be interesting to see if they violated their patent. http://www.starrotor.com/

Well, how are those critical thinking skills working out for you? Do you pay attention in your engineering lectures?

How does the weasel word count in http://www.starrotor.com/Engine.htm strike you?

They get around the seal issue by not having one. By making the rotors with tight tolerances, and by using the Brayton cycle rather than the Otto cycle, thus allowing lower compression ratios, they reduce leakage to a negligible level with no seals to deal with. I've got my eye on this company for the next few years. As for nutating engines, the seal issue probably will get the best of them, but it's still a neat concept that may see limited use.

Piston engines are obsolete anyway.

Say hello to your new rotary engine overlord.

http://www.starrotor.com/Engine.htm

I commend you on providing some reasonable objections to your own argument, but I think you missed out on some big ones, mostly on your assumption that electric cars are "practical" with today's batteries.

First off, this glossed over the energy cost per mile. Electric cars are quite terrible on this note. Sure, grid electricity is produced more efficiently than a car's engine power, but that's not the end of the line. Now that juice has to be pushed across the grid to your house, then pumped in to your battery, then pulled back out. This leaves the final cost per mile outside of the "practical" range, in the sense that it has a rough time competing with that massive storehouse of energy, gasoline. (remember, we tried electric cars in the very first days of automotive design-- we abandoned it because of these energy issues. at the time electricity was more common than gasoline, so there's no conspiracy, either)

Next, the idea that "200 miles is good enough" is a bit narrow. For a lot (most?) of commuters, I will concede the point. However, these commuters would kick any e-car's ass on a Vespa or even gigantic motorcycle. If we're serious about commuting cleanly, public transportation and two-wheelers are the way to go (especially bikes on trains-- one of the best ways to shuffle around many parts of Europe). In particular, I live in Texas, and use my car mostly for highway trips of 100 to 200 miles (I commute by bike). That 200 mile limit makes me a bit skittish, given the geography around these parts. Plus, most people forget that car engines, especially nice big American ones, are great on the highway. The high engine temp keeps pollutants down, and the lack of stopped time really helps overall MPG, irrespective of relative speed efficiencies.

Finally, the entirely restricted size of e-cars doesn't do much for my 6'4" 230 pound physique, let alone the massive moving of junk and people that is so wonderfully convinient with my hatchback. So, again, the e-car falls just a bit short of "practical."

I'm all for transportation efficiency, but the sheer physics and chemistry of it all means that liquid hydrocarbon fuels are essentially unbeatable. Thus, biofuels (from secondary waste, not corn kernels) and better engine designs are almost certainly a better idea than battery-only. There are plenty of wonderful ideas languishing because of the popularity of battery research-- e.g., we could double or triple the fuel efficiency of all cars on the road: http://www.starrotor.com/

Try again (no trailing slash): http://www.starrotor.com/Engine.htm

Take a look at this: http://www.starrotor.com/Engine.htm/.

The problems you mentioned with rotary engines are problems with Wankel rotaries. They use the Otto cycle (like regular piston engines), thus require high compression ratios. There's another engine in development that I would really like to see take off called the Star Rotor (http://www.starrotor.com/). It uses the Brayton cycle, which doesn't have to worry as much about seals and compression.

For those who are mechanically inclined, http://www.starrotor.com/ might be an interesting read. I've been hearing about this engine for a few years now, and it looks pretty promising. Personally, I'd love to have one under my hood.

I just recently saw this new design for a car engine and I wonder if this could help with the energy problem. One of the nice things about it (besides being 4x as efficient as an ICE) is that any reasonable fuel may be used as a heat source.

Any thoughts?