Question

The shape of the airfoil in both (x, y) and transformed (ξ, η) space are different.

(a) True

(b) False

I got this question at a job interview.

This intriguing question originated from Linearized Subsonic Flow topic in division Linearized and Conical Flows of Aerodynamics

Answer 1

Right option is (b) False

To elaborate: The shape of the airfoil in (x, y) space is given by y = f(x) and in (ξ, η) space is given by η = q(ξ). Since \(\frac {df}{dx} = \frac {dq}{dξ}\) hence the shape of the airfoil in both the spaces irrespective of the transformation remains same.