Question

The fundamental equation for the thin airfoil theory does not encompass which of the following approximations?

(a) The angle of attack and slope of the camber line is small

(b) Camber line induced velocity distribution is the same for chord line

(c) Vortex sheet is placed at the chord line

(d) Kutta condition is satisfied at the trailing edge

This question was posed to me during an internship interview.

The above asked question is from The Symmetric Airfoil topic in portion Incompressible Flow over Airfoils of Aerodynamics

Answer 1

Right option is (d) Kutta condition is satisfied at the trailing edge

Easy explanation: Kutta condition is always satisfied at the trailing edge. This is the boundary condition for the camber line to be a streamline also and is not an approximation. While the other three statements are valid approximations, which have been made under the assumption of a thin airfoil where camber and chord line is very close.