Investigation of unsteady parameter effect on aerodynamic coeffcients of pitching airfoilusing coarsegrid simulation

In this article, the eects of unsteady parameters, including mean angleof attack, oscillation amplitude, reduced frequency, and pitching axis position, on theaerodynamic coecients of a pitching airfoil are studied. this investigation is implementedfor high reynolds number ows around a dynamic stall condition. the employed numericalmethod is a coarse grid cfd (cgcfd) method, in which the euler equations are solvedusing a coarse grid with no slip boundary conditions, and a compressible surface vorticityconnement technique. the required computational time for this method is signicantlylower compared to that of the full navier-stokes equations with a simple one-equationturbulence model. in addition, a multi zone adaptive spring grid network is applied tosimulate the moving boundary, which further reduces the computational time. usingthe described numerical setup separates the current work from the others. the obtainednumerical predictions are in very good agreement with experimental data for the highreynolds number ow. it is found that moving the pitching axis position to the right orleft outside, and distancing it from the trailing edge or leading edge, has an inverse eecton aerodynamic characteristics. furthermore, increasing reduced frequency results in areduction in the lift hysteresis loop slope, and in the maximum lift and drag coecients.