The rainbow trout is able to laminarize the boundary layer forming on its skin in order to maintain a laminar boundary layer, reduce the skin friction and be more energy efficient when swimming. The velocity profile on parts of the trout can be analyzed using the Falkner-Skan equation, which includes pressure gradients in the analysis of boundary layers. This lesson will show the main aspects of this equation.
Boundary layers, however, are not only two-dimensional. Indeed, flow over a delta wing generates a secondary motion that affects the velocity profile of the boundary layer. In this lesson we will extend the governing equations for a boundary layer to analyze also three-dimensional flows.
These and other methods that extend the range of applicability of the boundary layer theory will be explained in this lecture.
Here are the accompanying hand-out slides for this lesson.