Are Wankel engines piston engines?

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14 years 3 months

Posts: 1,101

See http://www.flightglobal.com/articles/2009/05/24/326897/mistral-prepares-piston-engines-for-certification.html The engines are repeatedly described as "piston" engines. But are wankel engines piston engines? Also, what exactly is a "rotary" engine? Surely a rotary engine is a reciprocating engine where crankshaft is fixed and pistons move?
Original post

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10 years 6 months

Posts: 126

Wankel Engines A Wankel Engine is a Rotary engine, it does not contain any crankshaft or pistons nor does it look like a normal internal combustion engine either externally or in its design. If you imagine a triangular sponge baking tray, with a hole in the middle for a drive shaft coming up through and connecting to a three bladed rotar with seals on the end which sweep round intaking fuel/air mixture in one area, exploding in next area, exhausting in third area, etc.. This is obviously a very crude outline, to understand rotary engines you must read some books on engine design, they do have a number of advantages, size and smoothness of running among them. Hope this helps. Cheers Brian.:)

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14 years 3 months

Posts: 1,101

And Wankel engines are certainly not reciprocating engines. Thus, they are neither reciprocating nor turbine engines. What are the relevant performance requirements? From http://www.flightsimaviation.com/data/FARS/part_121-183.html planes with 4 or more reciprocating engines must sustain a certain rate of climb at a certain height with 2 engines out. But for planes with 2 inoperative out of 4 or more turbine engines have different requirements: http://www.flightsimaviation.com/data/FARS/part_121-193.html the climb rate must merely be positive, or indeed less. What precisely are the performance requirements for a plane with 4 or more Wankel engines, with 2 engines out? Seeing how neither reciprocating nor turbine engines apply?