Some remarks on transonic potential flow theory

The validity of the commonly used transonic potential equation for flows with shock waves is examined. It is concluded that in such cases the potential formulation is inconsistent with the basis assumptions of the theory because of the nonconservation of momentum across a shock. The relationship of this momentum source to wave drag is also discussed. Another topic examined is the rationalization of means to make solutions of the transonic potential equation agree better with solutions of the Euler equations.