曲面形栅格翼气动特性研究

与常规栅格翼布局相比，曲面形栅格翼布局减小了栅格翼翼元的等固壁通道的长度，从而有效降低了翼元内气流的壅塞，另外，这种栅格翼布局结构简单，易于折叠，减小了飞行器的轮廓尺寸，具有很好的工程应用前景。本文通过数值模拟方法，在亚、跨、超声速条件下，研究了曲面形栅格翼布局的减阻效果和减阻机理，对比了曲面形栅格翼和常规后掠形栅格翼布局的减阻效果，并对不同迎风方式的曲面形栅格翼气动特性进行了分析。

Investigation of aerodynamic characteristics on circular-arc grid-fin configurations

In order to reduce flow choking and the corresponding high drag force,an im-proved circular-arc grid-fin configuration is proposed in the present study.Compared to the con-ventional grid-fin configuration,the circular-arc layout decreases the length of the fin cell as to reduce the flow choking.Meanwhile,the circular-arc grid fins can be conveniently folded against the body so as to make them easier to store and transport.Viscous computational fluid dynamic simulations were performed to investigate flows over single grid fin.Comparisons of drag coeffi-cients between circular-arc and sweptback grid fins indicate that both configurations have signifi-cant drag reduction under subsonic、transonic and supersonic than baseline grid fin configuration. However,when the flow velocity is above the third critical Mach number,the drag reduction of circular-arc grid fin is higher than that of sweptback grid fin.Through aerodynamic analysis of two different windward forms of circular-arc grid fins,it is clear that before the third critical Mach number,the lift coefficient of the convex plane windward model is much greater than the concave plane windward model (approximately 30%)and the baseline model,after the third criti-cal Mach number the lift coefficient of the convex plane windward model and the baseline model tend to be consistent,while the concave plane windward model has a greater lift coefficient.