Abstract:
For the study on drag reduction principle of variable camber wing, the parameterized model was built and validated. Based on this model, the common research model of Boeing was investigated, and the influence of camber variation by leading and trailing edge deflecting was analyzed on aerodynamic characteristics, pressure coefficient, and spanwise load distribution. Besides, the optimal camber ratio under different lift conditions in cruise were studied, and the aerodynamic characteristic discrepancies caused by camber variation at trailing edge only was compared with those at both leading and trailing edge. The results indicate that, the variation of aerodynamic characteristics is significant by deflecting the leading or trailing edge, and the variation is greater with only the trailing edge deflected. For a given lift condition, the camber variation leads to the variation of local angle of attack and camber, resulting in the reduction of shock wave drag and induced drag. The drag reduction from camber variation, less than 0.0001, is insignificant at low lift coefficient. However, at high lift coefficient, camber variation can reduce the root bending moment and improve the shock wave induced separation, leading to about 0.0010 drag reduction. Compared with camber variation by trailing edge deflecting, that by deflecting leading and trailing edge simultaneously leads to further suppressed pitching moment increasing near the buffet boundary and more drag reduction. The parameterized model is of high efficiency in 3D geometry and mesh generation, and the influence of profile quality can be avoided. The conclusion of camber variation principal can be used as reference for wing design in industrial application.