Duke engines, concept and video

[flipwils11]

Any mechanical engineering members out there? This was posted on another forum and something about it just doesn't seem right to me (but I'm no engineer).

http://youtu.be/c19kn3drdFU

[bearrickster]

Any mechanical engineering members out there? This was posted on another forum and something about it just doesn't seem right to me (but I'm no engineer).

http://youtu.be/c19kn3drdFU

looks cool anyway I think it could work

[Halgar]

That does look cool, wonder how they managed to seal the stationary head against the rotating engine block, or should I say Cylinder core?

[terry.sc]

Any mechanical engineering members out there?

I have an Automotive Engineering degree, even though I've never had much use for it since leaving university so I guess that kinda qualifies me.

There are several problems with it, compared with a normal engine. First you have the problem of the seals between the rotating engine block and stationary head which shouldn't be too much of a problem, but those seals have to pass over the inlets and outlets without damage so could be interesting to see how long they last.

Also as well as the pistons going backwards and forwards you also have the cylinder block rotating, that's a lot of extra inertia to speed up and slow down. In a normal engine you have the pistons connected to the crankshaft, the crankshaft compared with the rotating cylinder block has a much lower rotational mass so a normal engine will be able to accelerate and decelerate much faster than the Duke motor.

Then you have cooling problems. If the cylinder block is rotating at speed how do you get coolant through it to remove heat. getting coolant in would be easy, through the centre pivot, but as the coolant will be thrown to the outside due to the high speed rotation.

With the centrifugal forces all the pistons will be thrown to the outside of their cylinders. Now while normal pistons do rock from side to side in their cylinders as the crank rotates the load isn't constant, in the Duke engine there is much bigger loads pushing the piston and rings against the outside side of the cylinder all the time the engine is running.

While I'm sure it would have its uses, as a prop engine seems logical as speed can be pretty constant and it could be air cooled, but it isn't going to replace a normal combustion engine.

[Quartermilecrazy]

I am no engineer, but I have built quite a few 1000HP engines and I am not seeing a rotating engine block or cylinder head anywhere in this video.

The major problem I see with the engine is the "ball cup" that the connecting rod attaches to the crank. Seems like it would cause a problem to me. With no bearing in there what is preventing wear? It looks like an interesting concept but would it last 100,000 miles like conventional engines do? There is a reason that the standard reciprocating engine is so often used is because it simply works. The most successful variant is the boxter engine, which has two opposing banks of cylinders. The Wenkel rotary engine is a proven design that works, but again, reliability issues keep it from being very widespread.

I think that reciprocating engines are getting close to the pinnacle of their efficiency, and it will take something drastic to make the next big step in efficiency and power. I may be a little impartial, but the newest versions of BMWs engines seem to be at the top of the list for engines that have the best compromise of weight/power/efficiency. I think turbo technology still has a little bit of a ways to go before it reaches its pinnacle. So we can only sit back and watch and see what the engineers have up their sleeves.

[GoMachV]

IMO the "next great thing" in engine technology will need to not be reciprocating. Having a piston and rod changing speed 100 times a second is not efficient. Just my $.02 but I don't see that technology going much further

I will say tho, the OPOC engine has always intrigued me, plus it has some serious investors behind it
http://www.ecomotors.com
[youtube]uP7gGUCPJj0[/youtube]

[Coelacanth]

That was pretty cool, but I found their tagline, "The power of symmetry" rather humorous, considering the engine has 5 cylinders. Both inline and V-arranged engines are actually more symmetrical than the Duke engine.

[Quartermilecrazy]

That was pretty cool, but I found their tagline, "The power of symmetry" rather humorous, considering the engine has 5 cylinders. Both inline and V-arranged engines are actually more symmetrical than the Duke engine.

Not necessarily. Cylinders arranged in a circular pattern will always be more symmetrical because the forces of the piston are always going in the same direction, centrifugally. As opposed to a inline or v configured engines, the pistons travel is always fighting other pistons. In fact, I dont remember for sure, but I dont think I have ever seen a radial engine with and even number of cylinders. That is where the inefficiency comes from.

Yes, looks wise, symmetry would be an even number of cylinders but I dont think they are referring to the looks of the engine.

[Coelacanth]

That was pretty cool, but I found their tagline, "The power of symmetry" rather humorous, considering the engine has 5 cylinders. Both inline and V-arranged engines are actually more symmetrical than the Duke engine.

I dont think they are referring to the looks of the engine.

I was.