Why still no dive acceleration difference?

[BlackBerry]

3-blade and 4-blade diagrams are from university textbook of aerodynamics.

I don't know those props are modern or WWII era. So they are just for demonstrate, but apperently, xfu4-1 13.5ft naca16 or clark y propeller is much inferior to that 3-blade diagram. For example, 400mph @6000m xf4u's efficiency is 70%, advance ratio=2, while in that 3-blade diagrams, could reach 85%+. So this implies that fw190a8 will completely lose its power much below 950km/h@6000m. Sad news for germans, because bf109/fw190 including Ta152 are equipped with 3-blade prop. while allied had 4-blade after 1942. Even worse for soviet planes, la5/la7,yak are light, small size plane which means their dive acceleration are poor within 730km/h.

BWT, prop. efficiency decreases when altitude grows, and I don't know whether those diagrams are sea level or 9000 m.


I am afraid that the efficiency diagrams of WWII era are difficult to find. The last choice is "ansys" which is powerful software in simulating propeller.