Question

What is the blade element theory used for?

(a) Predict performance of airscrew airfoil

(b) Predict performance of wind turbine

(c) Predict performance of supersonic airfoil

(d) Predict performance of flat plate

I had been asked this question in a job interview.

The query is from Blade Element Theory in division Helicopter Dynamics of Aerodynamics

Answer 1

The correct choice is (a) Predict performance of airscrew airfoil

For explanation: The blade element theory is used to predict the performance of an airscrew blade which is a type of lifting airfoil used in helicopters. It can be replaced by a single hypothetical bound vortex which sheds vortex from the tip of the blade.