Liquid Piston - DARPA recipient for drone engine technology. Could be revolutionary.

[Skydancer2992]

Inverse wankel design. Hybrid electric/JP8 engine. Engine is about one third the size of an equivalent piston engine and has substantially fewer moving parts.

 

 

[carusoam]

One of the challenges with rotary engines... is keeping oil sealed...

Wondering how well they manage this with the air cooled engine...

Best regards,

-a-

[Skydancer2992]

On 9/15/2020 at 7:35 PM, carusoam said:

One of the challenges with rotary engines... is keeping oil sealed...

Wondering how well they manage this with the air cooled engine...

Best regards,

-a-

The problem with the Wankel design was it was basically a triangle with three sharp tips which were subject to wear, resulting in burning oil with the telltale blue smoke.
 

The nice thing about the Wankel was that each rotor was an individual engine, providing power if one of the others failed. Also, the RPM was limited to the amount of heat that could be dissipated, making temporary increases of power beyond the engine constant output rating possible.