I am stuck on a homework question, all because I dozed off in class.
I understand what a stream function is but I don't know how to apply it to calculate the flow in pretty much anything.
Here's the problem I am stuck on. I choose to not give out the question in it's entirety.
An incompressible stream function is given by $\psi (x,y)$ .Use the stream function to find the volume flow passing through the rectangular surface whose corners are defined by (x,y,z)=(2L,0,0),(2L,0,b),(0,L,b) and (0,L,0).
My Doubt Where do I apply the stream function, at the corners of the rectangular surface or the midpoints? Or am I going in the wrong direction?