Potential Flow

Potential flows correspond to irrotational velocity fields: this irrotationality is first shown to be persistent for perfect fluids of zero viscosity. Simple examples of such flows (or approximations of them) are given. The velocity potential is then introduced and illustrated by a number of examples such as potential flows around an obstacle of arbitrary shape and Magnus force when the circulation of the velocity around the obstacle is non zero. Linear surface waves along the surface of a fluid are then presented and also represent an example of potential flow. The following section discusses the analogy between potential flow and electromagnetism. Finally, the chapter introduces the concept of a complex velocity potential and of the conformal mapping technique which are then illustrated by a number of examples of fluid flows.