Simulation of Cascade-Gust Interaction by Using Grid-Optimized Dispersion-Relation-Preserving Methods

Prediction and reduction of unsteady turbomachinery noise is the main issues for reducing overall acoustic emission for subsonic vehicles with high bypass ratio engines. This paper presents a numerical analysis of cascade/gust interaction using a time-marching solution of the unsteady, nonlinear Euler equations of which the spatial derivatives and the time integration are computed by using Grid-Optimized Dispersion-Relations-Preserving (GODRP) schemes and 3rd-other optimized Adams-Bashforth method, respectively. The incoming periodic gusts are specified through the subsonic nonreflecting boundary condition with care. Comparison of results for a flat-plate cascade with results using analytic theory demonstrates this method s capability to accurately predict unsteady response of periodic gust. Application of these methods and results for benchmark problem 2 of Category 3 are implemented.