CFD aerodynamic models for separated flow on high aspect ratio flexible wings

In this paper the process of determining semi-empirical coefficients for three dynamic stall models is demonstrated using Computational Fluid Dynamics (CFD). Results of the models are then evaluated against two-dimensional Unsteady Reynolds Averaged Navier-Stokes (URANS) and it is seen that the models can capture unsteady aerodyanmic nonlinearities. This work is then extended to model separated flow and dynamic stall on a finite wing. In order to do this, a correction is applied to the Unsteady Lifting Line Theory (ULLT) using two-dimensional viscous data, which can be obtained either from two-dimensional URANS or a dynamic stall model. The ability to couple ULLT to a dynamic stall model allows for fast unsteady, three-dimensional and nonlinear load predictions, without relying on a vast URANS database. For this reason it is also possible to use the model within aeroelastic calculations.