The Development of a CFD-Based Model of Dynamic Stall

A vorticity confinement CFD model has been developed and applied to dynamic stall computations. The advantage of the model is that it allows dynamic stall computations to be performed on inviscid-sized grids. The coarseness of the grids allows large time steps to be taken relative to those required for viscous grids. This in turn results in large computational savings, and the possibility of applying this CFD-based method to engineering methods, such as comprehensive helicopter codes. The model is applied to NACA0015 and VR12 airfoils, and results are compared to experimental data. The computations demonstrate the ability of the confinement model to control the point of separation, and to generate the important flow features associated with dynamic stall. The vorticity confinement models are found to yield results that compare favorably with the best conventional (e.g., RANS) computations, and for far less computational cost.