Lifting bodies and circulation

This chapter presents the notions related to lifting bodies. In particular, the definitions of the lift force, the center of pressure, and the angle of attack are discussed. The notions of bound, shed and trailed vorticity are introduced. Different engineering models devised to modify the polar data of an airfoil are presented, such as: the extension to full polar, the determination of fully-separated polars, and dynamic stall models.

Vorticity-based theories of lifting bodies are briefly mentioned. Lifting-surface and lifting-line theories of a wing are presented since they are relevant for the numerical implementation and validation of vortex-methods for wind turbines. The lifting-line approximation is also extensively used in this book for the representation of wind turbine blades.