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Toroidal Engine Ready for Production
FarceMajeur writes "Business 2.0 has a column on a recently prototyped "round engine," properly named a toroidal engine, by VGT Technologies, Inc. Nice Flash animations of the concept are here. I've always admired the Wankel engine, but it seemed more like a time bomb than a going concern. This engine is billed as the 'world's first practical Concentric Positive Displacement Engine,' meaning no eccentric rotation to generate vibration, meaning fewer catostophic failures, one would hope."
This engine was developed primarily by people at the University of Calgary, not SAIT. He only teaches at SAIT, they didn't have much at all to do with the development of the engine as far as I can see.
Anyway, it's an interesting piece of technology.
Random and weird software I've written.
Reciprocating pistons and poppet valves still live because they work well, can be manufactured with simple operations and have seals (piston rings and valve seats) that will last for years.
I thought about a design like this many years ago and concluded that there would be major difficulties sealing in the combustion gases. I guess time will tell whether the problem has been solved.
"Eve of Destruction", it's not just for old hippies anymore...
How does the main flywheel maintain its rotation? If it's transferring energy to another wheel, it will slow down, friction notwithstanding. One would think that pistons would still be needed to keep the big wheel turning.
"Times have not become more violent. They have just become more televised."
-Marilyn Manson
Well, I looked at the animations. Neat idea, I think. But what happens if that timing belt goes? It looks to me like the thing would smash itself to pieces.
What would happen if a timing belt gave out on a 'normal' cylinder-based engine? I'm not too knowledgable about engines, but it doesn't seem like it would be quite as catastrophic.
No they are not useless from a technical POW. One of the alternative designs should be used if we had to redesign all of engines, factories, fuels, motor oil and car's form factors. The design we use now is not the best one, it just happens to be the one whole automobile industry is shaped around. So it can only be replaced if an alternative is significantly better, while -to my knowledge- no alternative design is.
Gentlemen, you can't fight in here, this is the War Room!
IANAE, but this is likely to be a crackpot/scam venture.
The phrasing I've quoted above, which come from the web site, are big red flags. They're trying to pitch Pekau instead of the engine. Along the lines of "he's really smart and knows what he's doing, so of course his engine works." This is how scam after scam after scam gets pitched. "Ignore all the nay-sayers, because they just don't understand what our guy has done."
The phrase "which is well-documented" is also a tip off. Nobody says that unless it's not quite true.
- light and medium petroleum distillates;
- petroleum byproducts such as propane;
- methane (fossil or biogenic);
- vegetable oils and derivatives such as biodiesel;
- heavy petroleum fractions;
- wood, wood gas and charcoal;
- coal.
For any one of those fuels, I can cite an example of one of the above families of engines running on it. If an engine isn't being widely used, it's because it's difficult to manufacture or requires expensive materials. Right now we are using the least-expensive (and thus most cost-efficient) technology we've got, and that's the right thing to do. In a word, hogwash. There are a host of different engine designs around, and some of them have even achieved some presence in the marketplace. Examples:- Wankels
- Stirlings
- Gas turbines
We don't use the Wankel because it has too much chamber surface area per unit displacement, causing heat losses to be greater than a piston engine and losing the efficiency race. We don't use Stirlings because they are external-combustion engines requiring very high temperatures to be efficient, and the materials for the hot-side heat exchangers are not cheap. We don't use gas turbines because they require (again) heat exchangers to be most efficient, and (for vehicles) nobody's come up with a design which isn't either too bulky or loses too much efficiency to leakage; for road vehicles, turbines remain the province of superchargers, not the main power producers.A lot of research money has been expended on these engines in the past. Superior technologies do win out, just as fuel injection has displaced carburetors from all US production cars. If you can come up with a way to beat the technical problems which prevent any one of these engines from being manufactured as cheaply as a piston engine while meeting the same efficiency, emissions, noise etc. requirements, the world will beat a path to your door.
Scientists restrict study to entire physical universe; creationist
The total gyroscopic moment of the wheels in the toroidal engine can be computed as the vector sum of the angular momenta of the two pieces. This isn't quite intuitive, but it's not rocket science either.
It's easy to answer this question, because it's been done.The real issue is that this engine probably can't be manufactured to the required tolerances (especially over temperature), and its large surface areas will probably keep its thermal efficiency lower than piston engines. This puts its claims well toward the "scam" category
Scientists restrict study to entire physical universe; creationist
the problem is always pressure seals, and take a look at what would be needed for the 'flywheel' on this one. wake me after they've dealt with that, and i expect it'll be some years, if ever.
/. editors: guys, there's 'brilliant new combustion engine' designs all the time, and they never go anywhere. don't touch these articles unless they get real backing. you're outside your expertise and sliding us towards the worst of Popular Science. no offense; i know you don't know.
the wankel worked, btw. it just didn't turn out to be much more efficient because the piston-crank method is so refined. it was more of a marketing disaster because mazda made them a little too cheaply after a big PR campaign. they had to remove it from their sedan line but could keep in their sports car because those customers read a little more.
and it's very hard to think of a simpler or more efficient seal than the piston ring & cylinder combination.
the compression rings [there's a few others doing things like oil] are very like split ring washers, and expand to meet the cylinder wall. in the piston they're still sitting in the ledge of their groove for support, and the pressure holds them tight against it. but they're free to rotate around the piston, so you get even wear between them, the cylinder walls, and their grooves. and because they expand to contact, they can take an amount of wear over time before they're not reaching the cylinder walls effeciently.
you'll have to at least match that before you can begin to test if this 'new' design is any more efficent.
and quotes for 'new' because they are indeed hundreds of really interesting concepts from the last century. many were successful in fields other than automotive. worth geeking out and digging into the history. [turbines are well known. whittle was looking at turbo assited piston engines and realized with a bit of work you could throw away the 'engine'. brilliant rotarty solution.]
oh, and a note for
Those tight fit parts that absolutely fly by each other have to meet, slide, and keep a pretty good seal. Each time the timing chain is a little off, say to increase or decrease in power, they will miss a little, bonk, and get worn. Hot exhaust gasses slipping through will probably cause preignition in the little transfer tube. Nasty.
Also notice how much physical distance the compression arms of the rotor have to move each cycle. Can you imagine the heat from friction and the lubrication required? And the kinds of seals that you would need? I guess you could get decent lubrication by using the rotor as some sort of centrifugal oil pump, but still the wear would be nasty.
Consider as well that it's basically a 2 cylinder 4-stroke engine. It's gotta be a pretty good size and run at a pretty high RPM to get enough power to be really useful.
Don't count on this one.
Nope. Read the white paper. It describes the compression and expansion clearly. Here's the process:
Advantages:
Disadvantages:
Overall, this is one of the more promising alternative designs that I have seen.