matula11

What is the technical name of the shape of the rotor in a rotary engine. I know its a stupid question, just wondering. Thanks

Boostmaniac

My first impulse was to go with triangle, but I know there is a much larger word that describes it much better.

Evil Aviator

The inside of the rotor housing is a peritrochoid shape, and the rotor is shaped to fit inside of it. I guess the rotor shape is best described as a Reuleaux triangle. Hopefully some of the advanced math folks on the forum can come up with a more accurate description.

PercentSevenC

Rotors are similar to, but not exactly, Reuleaux triangles. They are more flattened on the faces than a true Reuleaux triangle.

monkhommey

if you want to know about geometry then this is interesting reading.

http://www.personal.utulsa.edu/~kenn...n/chapter7.pdf

this paper gives some interesting insight into eccentricity ratio and some other cool things. evil aviator.. i believe that is an accurate description of the shape.

diabolical1

iTrader: (3)

i don't know if this is very helpful, but you might want to see what organic chemists have to say about the shape of cyclopropane. i remember when i was taking orgo, the stress of the bond made it curve like a rotor. worth a shot, eh?

oh and monkhommey, thanks for that paper.

ikari899

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

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

Blake

The rotor shape is called a 3-flanked Hypotrochoid, which is the inner envelope of a 2-lobe Peritrochoid. This according to Rotary Engine by Kenichi Yamamoto.

Boostmaniac

Blake wins.

ROTARYROCKET7

trochoid rotors spinning in an epitrochoid curve.

micah

Big.....Words...... Hurting...... Brain.........

Why not just call it an inflated triangle.

Edit: better yet, a triangle.... WITH BOOST!

patman

iTrader: (3)

i would say the description most likely to be understood by your friends is: "its like one of thsoe 3d doritos"