What is the shape of the pressure curve on the upper surface of a thin diamond wedge airfoil at zero angle of attack?

A)
Pressure increases and becomes constant
B)
Pressure decrease follows a parabolic path
C)
Pressure decreases linearly in a straight line
D)
Pressure increases instantly and becomes constant, and then suddenly becomes negative and becomes constant

Correct Answer :   Pressure increases instantly and becomes constant, and then suddenly becomes negative and becomes constant


Explanation : According to shock expansion theory, shock wave interactions determine the aerodynamic loads on the surface of the airfoil. Oblique shock and expansion waves decrease and increase the pressure respectively.