Question

The stream function can be obtained by _______

(a) sum of stream function of uniform flow and doublet flow

(b) difference of stream function of uniform flow and doublet flow

(c) sum of stream function of uniform flow and source flow

(d) sum of stream function of uniform flow and sink flow

I had been asked this question by my school teacher while I was bunking the class.

My question is taken from Nonlifting Flow over Cylinder topic in chapter Inviscid & Incompressible Flow of Aerodynamics

Answer 1

The correct choice is (a) sum of stream function of uniform flow and doublet flow

To explain: The stream for the resultant flow can be given by the sum of stream function of uniform flow and doublet flow. Here we need to consider cylindrical coordinates. Mathematically,

Ψ = U*y + ((-u/2*pi*r)*sin θ.