Paul

 Are the inside of the scoops an airfoil?
tonys longez

Yes. The shape or curve has the same goal as an airfoil
and that is to keep the air attached to the surface
of the duct (AKA diffuser) as long as possible.

This is a plot of the K & W coordinates published in my book
"How to Cool Your Wankel" on page 29. The shape of the exit
duct is also important for low cooling drag.

Good work Tony.

Paul Lamar