1.2 The Velocity Potential Equation For two-dimensional, steady, irrotational, isentropic flow,a velocity potential =o(x, y) can be defined such that V=VO The introduction of velocity potential can greatly simplify the governing equations, we can derive the velocity potential equation from continuity, momentum, energy equations11.2 The Velocity Potential Equation For two-dimensional , steady, irrotational , isentropic flow, a velocity potential can be defined such that :  = (x, y) V =  The introduction of velocity potential can greatly simplify the governing equations, we can derive the velocity potential equation from continuity, momentum, energy equations: