New Rotary Engine

[SagaLore]

Originally posted by: Evadman
You have your rotation of the "head" backwards. The way it is now would snap the connectiong rods. The "Head" and output must both turn the same way, unless I am missing something.

Check out ElFenix's pic tweak. He got it.

And yes, there wouldn't be a need for valves; just ports.

As far as cooling, I figured the inner and outer wall of the large housing would be finned and this could be efficiently air cooled.

 

[SagaLore]

Originally posted by: ElFenix
ah i get it, the whole thing rotates together at the same rate, but because one ring is at an angle to another you get power just after the top part and exhaust near the bottom

like this

it wouldn't need valves just ports

Yep. But your edit has the intake/exhaust/ignition upside down based on where the piston is at relative to both drawings.

Since one revolution of the rotors would account for only half the otto cycle, I either need another disc on top of the ports that spins at half the speed of the rotors to form some kind of off/on port system to force a completion of 2 revolutions - or this becomes a two stroke engine. Since there are so many pipes inherent to the design, and both rotors move, it wouldn't make sense to use spark plugs.

This might be useful as an air compressor - but perhaps the combustion could take place in a stationary chamber, and the expanding gases power the pipes. Could work for steam too.

 

[jagec]

Originally posted by: Evadman

Originally posted by: Viper GTS
All other issues aside, how do you plan to cool this thing?

With no block + cooling system to dissipate heat into those pipes are going to get damn hot.

Viper GTS

Ceramic block? That would be most efficient at keeping the heat in the cyl where it should be.

Err, a heat engine needs a low-temperature sink to dump heat into.

As for the OP, I really wish I could find the page, but there was an early aircraft engine that basically used your design. It was a rotary design where the cylinders rotated, rather than the crank. Apparently it produced some interesting gyroscopic effects too...

 

[ElFenix]

Originally posted by: SagaLore

Yep. But your edit has the intake/exhaust/ignition upside down based on where the piston is at relative to both drawings.

no wait... isn't the compression the highest at the top end?

 

[SagaLore]

Originally posted by: jagec

Originally posted by: Evadman

Originally posted by: Viper GTS
All other issues aside, how do you plan to cool this thing?

With no block + cooling system to dissipate heat into those pipes are going to get damn hot.

Viper GTS

Ceramic block? That would be most efficient at keeping the heat in the cyl where it should be.

Err, a heat engine needs a low-temperature sink to dump heat into.

As for the OP, I really wish I could find the page, but there was an early aircraft engine that basically used your design. It was a rotary design where the cylinders rotated, rather than the crank. Apparently it produced some interesting gyroscopic effects too...

You mean this?

development of the aero engine

 

[SagaLore]

Originally posted by: ElFenix

Originally posted by: SagaLore

Yep. But your edit has the intake/exhaust/ignition upside down based on where the piston is at relative to both drawings.

no wait... isn't the compression the highest at the top end?

Um... yes, so I guess your location for the spark is correct. But the expansion is at the greatest on the bottom, so the intake and exhaust can't be there. So they have to be closer to the top.

I take that back what I said about not being able to use spark plugs - duh - we'd just need one at the compression port. But we need a way to complete the otto cycle for efficient fuel burn. Otherwise use the idea in my previous post - burn everything in a pre-chamber.

 

[desy]

Looks like a K cycle engine we researched in physics 20 yrs ago.
I had a friend who worked on the proto-type but it got bought by a Japanese auto manufactuer.
He said it ran once they got appropriate back pressure, problem with any of these types of engines is sealing them properly. It was a pretty obscure design and I can find any images but I can see it in my head

 

[SagaLore]

Originally posted by: desy
Looks like a K cycle engine we researched in physics 20 yrs ago.
I had a friend who worked on the proto-type but it got bought by a Japanese auto manufactuer.
He said it ran once they got appropriate back pressure, problem with any of these types of engines is sealing them properly. It was a pretty obscure design and I can find any images but I can see it in my head

Draw it.

 

[desy]

Haw!
I make stickmen look bad!

I'll phone Richard and see if he has another name I can query on.

 

[jagec]

Originally posted by: SagaLore

You mean this?

development of the aero engine

that's EXACTLY what I was thinking of.

 

[SagaLore]

Originally posted by: jagec

Originally posted by: SagaLore

You mean this?

development of the aero engine

that's EXACTLY what I was thinking of.

Not quite like the Pipe Diffusion engine. Those engines still need valves. And the radial engine at the bottom still has an imbalance that will cause vibration. Now if they were to take two 3-cyclinder radial engines, and put them 180 degrees out of phase on the hub, then you could get rid of some of the vibration...

 

[Mo0o]

Well this is one way to spend your free time

 

[Quixfire]

Originally posted by: Evadman

Originally posted by: Viper GTS
All other issues aside, how do you plan to cool this thing?

With no block + cooling system to dissipate heat into those pipes are going to get damn hot.

Viper GTS

Ceramic block? That would be most efficient at keeping the heat in the cyl where it should be.

He could design the engine to run on methanol, which creates half the heat a gas engine develops.

 

[SagaLore]

Originally posted by: Quixfire

Originally posted by: Evadman

Originally posted by: Viper GTS
All other issues aside, how do you plan to cool this thing?

With no block + cooling system to dissipate heat into those pipes are going to get damn hot.

Viper GTS

Ceramic block? That would be most efficient at keeping the heat in the cyl where it should be.

He could design the engine to run on methanol, which creates half the heat a gas engine develops.

I was thinking Ethanol, with some water in the fuel, so whatever excess heat is produced will be turned into steam to aid in expansion. The rotation of the engine will keep it somewhat air cooled. But for efficient burn, I will need to use a lot of compression and diesel injection of fuel, rather than a spark plug.

edit:
Hmm... I wonder if we could just put in two injectors, one for fuel and one for air? That would solve the problem of a rotation only being two strokes... but then we'd need a spark plug to ignite it as it's injected, since there is almost no compressed gases in the chamber. Nah that doesn't sound like it would burn efficiently... or would it?

 

[Howard]

Originally posted by: SagaLore

Originally posted by: Quixfire

Originally posted by: Evadman

Originally posted by: Viper GTS
All other issues aside, how do you plan to cool this thing?

With no block + cooling system to dissipate heat into those pipes are going to get damn hot.

Viper GTS

Ceramic block? That would be most efficient at keeping the heat in the cyl where it should be.

He could design the engine to run on methanol, which creates half the heat a gas engine develops.

I was thinking Ethanol, with some water in the fuel, so whatever excess heat is produced will be turned into steam to aid in expansion. The rotation of the engine will keep it somewhat air cooled. But for efficient burn, I will need to use a lot of compression and diesel injection of fuel, rather than a spark plug.

edit:
Hmm... I wonder if we could just put in two injectors, one for fuel and one for air? That would solve the problem of a rotation only being two strokes... but then we'd need a spark plug to ignite it as it's injected, since there is almost no compressed gases in the chamber. Nah that doesn't sound like it would burn efficiently... or would it?

I believe that you don't get any extra torque from having a higher water content in the intake charge. Even if the gaseous form of water exerted a higher pressure at a given temperature, much of the water is in that form anyway, and whatever isn't requires a lot of energy (read: heat) to convert it to steam.

An air injector that flowed enough for an engine would basically be the equivalent of an electromagnetically-actuated valve, which we don't have right now.

Besides, you don't need diesel to have an efficient burn.
http://www.geocities.com/gkurk...etrol1.htm#Lean%20Burn