Whirlpools
Whirlpools may be approximated by a series of vortices of same signs advected into an uniform flow.
(a) Consider two vortices of equal strength K = +1 located at (-2,) and (+2, 0). Estimate how far away the effect of the vortices is perceived to be that of an unique vortex. What would be the strength of that vortex?
(b) Consider two vortices of equal strength K = +1 located at (-2,) and (+2, 0) in a horizontal uniform flow V = +0.03. What are the stream function and velocity potential of the resulting flow motion.