Question

4.8 In what sense are the potential flow solutions and the boundary-layer flow solutions
complementary?

Answer 1

The potential flow solution and boundary layer solution are complementary in the sense that potential predict the the flow by means of stream function and velocity potential but solution for the velocity distribution do not satisfy the no slip boundary condition at the wall.Hence potential flow solution are of no value in describing the transport phenomena in the immediate neighborhood of the wall.

To describe the behaviour near the wall boudary layer flow solutions are used.

For the description of a viscous flow, an approximate solution is develop for the velocity components in a very thin boundary layer near the wall, taking the viscosity into account. Then this solution is match to the potential flow solution that describes the flow outside the boudary layer