Which approximations are made in case of panel method in case of subsonic problems?

A)
Triangular panels with constant sink
B)
Quadrilateral panels with constant sink
C)
Quadrilateral panels with constant source strength
D)
Curved panels with constant source strength

Correct Answer :   Quadrilateral panels with constant source strength


Explanation : In case of panel method, the entire body is approximated into several smaller quadrilateral panels having constant source strength. Although when the bodies get complex, higher order panel technique is used, which makes use of curved panels with variable source strengths.