Are Wankel engines piston engines?

[chornedsnorkack]

See
http://www.flightglobal.com/articles/20 ... ation.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?

[machineman9]

Just got this off the Google machine:

"An engine which uses no pistons. In place of pistons, triangular-shaped rotors revolve in specially shaped housings."


Nice article on Wankel engines

Diagram to show what it does

[ShaneG_old]

After owning 2 RX7's, I can say with much assurance, that a Wankel is nothing like a piston engine.

Same results as a piston engine, just different means of achieving them.


I just wish they had solved the oil consumption problem on the old 12B motor. Nothing like having to detail your engine bay once a week.

[chornedsnorkack]

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/F ... 1-183.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/F ... 1-193.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?

[Brett_Henderson]

I think, as far as aviation goes, I'd call them reciprocating engines.

They use a version of "suck, squeeze, bang, blow"; it's just different geometry.

I always thought they'd be ideal aircraft powerplants. Their service life, and dependability in automobiles never could keep up with piston engines... BUT remember that scooting a car around requires regular ventures into RPM

[DaveSims]

[quote]I think, as far as aviation goes, I'd call them reciprocating engines.

They use a version of "suck, squeeze, bang, blow"; it's just different geometry.

I always thought they'd be ideal aircraft powerplants. Their service life, and dependability in automobiles never could keep up with piston engines... BUT remember that scooting a car around requires regular ventures into RPM

[Fozzer]

[quote]

[Brett_Henderson]

[quote]Actually, what is reciprocating in a wankel engine.

[chornedsnorkack]

How does the reliability of a car engine first produced in 1955 compare against the reliability of a car engine designed from scratch and first produced in 2008?

How would the in-flight shutdown rate of a plane engine designed from scratch in 2008 compare against the in-flight shutdown rate of a plane engine first produced in 1955 (Lycoming O-360)?

[The Ruptured Duck]

[quote]I think, as far as aviation goes, I'd call them reciprocating engines.

They use a version of "suck, squeeze, bang, blow"; it's just different geometry.

I always thought they'd be ideal aircraft powerplants. Their service life, and dependability in automobiles never could keep up with piston engines... BUT remember that scooting a car around requires regular ventures into RPM

[DaveSims]

How does the reliability of a car engine first produced in 1955 compare against the reliability of a car engine designed from scratch and first produced in 2008?

How would the in-flight shutdown rate of a plane engine designed from scratch in 2008 compare against the in-flight shutdown rate of a plane engine first produced in 1955 (Lycoming O-360)?

With the exception of a few new engine types, aircraft engines have remained relatively unchanged over the years.

As for flying past TBO, I'm not advocating just flying til it dies.  If you decide to fly past TBO, engine monitoring becomes important.  But if you have an engine with all 75+ compression and little to no oil consumption or other problems, why tear it apart.  It may never run that good afterwards.