A Unified Introduction to Fluid Mechanics of Flying and Swimming at High Reynolds Number

Modeling the flow around a deformable and moving surface is required to calculate the forces exerted by a swimming or flying animal on the surrounding fluid. Assuming that viscosity plays a minor role, linear potential models can be used. These models derived from unsteady airfoil theory are usually divided in two categories depending on the aspect ratio of the moving surface: for small aspect ratios, slender-body theory applies while for large aspect ratios two-dimensional or lifting-line theory is used. This paper aims at presenting these models with a unified approach. These potential models being analytical, they allow fast computations and can therefore be used for optimization or control.