Numerical Study of Unsteady Flows Past Airfoils with Hinged Oscillating Flap Using Direct Zonal Coupling Method

Abstract

A direct zonal coupling method was proposed for solving the flows past airfoils with a hinged oscillating flap in this study. The entire computational domain was divided into three zones. The grid in the zone around the hinged flap (zone 1) moves with the oscillation of the flap, whereas the grids in other two zones (zones 2 and 3) are redistributed to the position consistent with the grid in the zone around the flap. The governing equations in the moving frame were applied to zone 1 and those under the stationary frame were applied to zones 2 and 3, respectively. By using this kind of treatment, the grid on the zonal interface is 1-to-1 matched. The coupling between the zones is direct. Both the geometric and flow conservations are entirely satisfied. The unsteady flows past NLR7301 and NACA64A006 airfoils with a hinged flap oscillations were taken as the validation examples in the present study. The accuracy of the proposed method was demonstrated by the computational results compared with the experimental data.