Ever Wondered How a Rotary Engine Works?

[ATAG_Lewis]

[Combat Wombat]

For those who don't know how a four stroke engine gets it's name . No 1. intake fuel&air 2. compress the mixture 3. ignition & power stroke 4. exhaust stroke. it all happens in just a couple of passes of the piston in the cylinder.

[RAF74_Buzzsaw]

Not meaning any criticism of Lewis's illustration which is very interesting, but....

What Lewis's .gif doesn't show is that a aircraft Rotary engine rotates around its crankshaft... the crankshaft is stationary.

His diagram would suggest the cylinders are stationary... not the case.

The cylinders and rods whirl around the fixed crank.

Here is a diagram showing a Le Rhone:



Here is the valve and spark plug timing diagram:



Here is a uncovered rotary being started and showing the engine whirling around the fixed crank... the prop is attached to the whirling cylinders.



The rotary is one of the more interesting engines to model in Flight Sims, because you have to model the precession effects.

http://en.wikipedia.org/wiki/Precession

The spinning rotary cylinders act like a spinning top, they impart a torque to the aircraft beyond what you would experience in a WWII fighter with just the relatively lightweight spinning prop.... there is an effect when you attempt to move the spinning object off its center. This is especially noticeable in the very light WWI aircraft. When you attempt to turn left against the precessional effect, it cause the aircraft nose to rise... if you attempt to turn right, the nose drops... this was one of the reasons the Sopwith Camel had such a lightning fast turn to the right and tended to stall out in a left hand turn unless hard left rudder was applied.

Sopwith Camel with 160 hp Gnome Rotary... you can see some of the torque effects, although because the wheels are on the ground, the aircraft is anchored.



Pilot is using the 'blip' switch to cut a cylinders out to reduce power. The Gnome was a relatively unsophisticated engine... no throttle.

Below is a Sopwith Snipe with a 230 hp Bentley Rotary... did have a throttle.

[Combat Wombat]

Yes a radial and rotary ! two different modes

[ATAG_Torian]

I still don't get how the fuel/oil/air mix gets into the combustion chamber of the cylinder ? and how a throttle could control a setup like that ?

[Davis0079]

Rotary engine......I think in car mechanics....not aircraft....so my mind instantly went to this...we had a real cutaway of one of these out of a mazda RX-6 in my mech school...




I've always considered aircraft to be radial engines....i did know the early ones spun around the crank...but they were still radials in my mind....

[Skoshi_Tiger]

Wankel!

Just had to get that off my chest!




http://en.wikipedia.org/wiki/Wankel_engine

[Davis0079]

...very nice....Wankel...I will remember that.


....I said RX-6...must of been an RX-7 according to wiki

[Skoshi_Tiger]

...very nice....Wankel...I will remember that.


....I said RX-6...must of been an RX-7 according to wiki

Hot little motors by all accounts.

[Catseye]

...very nice....Wankel...I will remember that.


....I said RX-6...must of been an RX-7 according to wiki

RX2 and RX3 initially had them 1975'ish.
I was in warranty claims and owner relations for Mazda Canada then. This engine could really wind up. The big problem with them was fuel consumption - around 20 mpg or less for a subcompact vehicle just when gas prices were starting to go way up. The other big issue in design was the apex seals wearing out around or before 40,000 km and blowing oil all over the place and necessitating an engine rebuild.

[javelina]

Gotta admit, the Wankel engine is pretty cool. Years ago, I had a Mazda RX-7, and man would that Engine rev to high RPM's within a second or so. Smooth as butter... But I'd rather have something you can get parts for, and service real easy.