Simulation of Airfoil Response to Impinging Gust Using High-Order Prefactored Compact Code

Unsteady aerodynamic and acoustic responses of symmetric and loaded Joukowski airfoils to an impinging 2D vortical gust (Problem 1 in Category 3) are predicted using a nonlinear high-order prefactored compact code. The analysis is based on obtaining finite-difference solutions to the nonlinear Euler equations in the generalized curvilinear coordinates. The numerical formulation uses the low-storage 4th order 5-6 Low Dispersion and Dissipation Runge-Kutta scheme for explicit time marching, and prefactored 6th order compact scheme and explicit boundary stencils for spatial derivatives. A 10th order explicit filter is used at every stage of the Runge-Kutta solver to provide dissipation. C-grid 2D topologies are generated using GridPro software, with the mesh extending at least 10 chords away from the airfoil surface in each direction. The reported results were obtained through scalar and Parallel implementations on the Beowulf-type PC Linux cluster.