14 1. Basic Concepts of Fluid Flow
rotv = 0. (1.35)
From this condition it follows that there exists a velocity potential 45, such that
thgtdontniector can_l>_ed@fine_d_=;_s_21igrad_iP- I_he_conti,n_uitLequatio_n
for an incompressible flow, dive = 0, then becomes a Laplace equation for
the potential Q5:
div (gradsfi) = 0 . (1.36)