109 prop pitch (rpm) and the supercharger

[Al Schlageter]

bongo, what is the prop tip speed of a 3.1m prop at 2400rpm and 1500rpm?

[Crumpp]

Originally Posted by bongodriver

as soon as I'm shown data that says a prop turning at 1500 rpm is going to be efficient.....yes I would happily accept it, it's all I'm asking for and not a tirade of sarcasm.....so you can stick your little blue face up your rectum.

Maximum helical tip velocity is an important parameter for propeller selection. In the absence of specific data from the prop manufacturer, it is safe to assume that (a) the maximum prop efficiency will be about 87% (for any metal prop a non-governmental agency can afford), and (b) that the prop efficiency begins to decrease dramatically when the prop is operated at a helical tip velocity in excess of 0.85 Mach. That occurs because the local air velocity over the surface of the prop (near the point of maximum airfoil thickness) will reach Mach 1, and create a shock wave, separating the flow and dissipating prop energy.

http://www.epi-eng.com/propeller_tec..._propeller.htm

You should probably spend more time reading such things as the Pilot's Handbook of Aeronautical Knowledge instead of lurking on gaming sites if you are professional pilot who does not know this kind of basic stuff.

Just saying, it would be safer for you and your passengers.