The air obviously moves (is accelerated) more rapidly vice the surface in the rotating condition, so the comfortable assumption is to do with friction, and boundary layer? Why am I thinking something to do with Coanda?
Lift? A wing "lifts"? Doesn't it Push? By "fluid" do you mean liquid?
Is "Inviscid" in there anywhere?
Last edited by Lyman; 24th Jul 2012 at 19:50.