Liquid Piston? 40Bhp 75% Thermal Efficiency

[gone-ot]

...so, which is it that I'm smelling? Unicorn pharts or rainbow-colored road apples?

[RiderofBikes]

Originally Posted by Old Tele man

...so, which is it that I'm smelling? Unicorn pharts or rainbow-colored road apples?

I'm with ya this one still, but hey if something works(to a degree), then it still works, and still might find a place for itself

[mort]

Originally Posted by oil pan 4

On paper the otto cycle can be up to 73% efficient (if I remember correctly) so it would be nice to see how this one does in the real world.

Otto cycle efficiency is related to compression ratio. In theory the Otto cycle can get as close to 100% efficiency (but less than 100%) if you run a high enough CR.

If you include the slight advantage of having a larger expansion ratio, 75% efficiency requires a CR of about 30:1, Which I think is going to be expensive to deliver with the durability expected in modern machinery - considering those sliding seals, especially the end down by the axis. Mazda always had trouble with those seals.

-mort

[oil pan 4]

Pistons engines tend to be very good at extracting energy from fuel under lots of different loads and speeds.
Rotating and rotary engines seem to only be better under special conditions.

[RobertISaar]

it's a rotary, it makes a laughable amount of torque at all times, which is why they need to spin them to ridiculous RPM to get "impressive" HP numbers.

it could be used as a normal engine..... but it would require a non-"normal" transmission.... just have the engine idle at a fairly low RPM, then any kind of throttle would spin the engine up to a better point in the BSFC map and have a CVT trans keep the engine at that speed at all times.... but i imagine that would be quite an annoying vehicle to drive. but the same issue would be present as a "generator" engine.