基于运动嵌套网格的前飞旋翼绕流N-S方程数值计算

 通过求解 Navier-Stokes方程数值模拟了直升机旋翼前飞非定常流场。为了模拟包括旋转、周期性变距和周期性挥舞的非定常运动,采用了一种能够快速完成重叠网格间流场信息交换的运动嵌套网格方法。空间上采用中心平均的有限体积法进行离散,时间方向应用含隐式子迭代的双时间法推进求解。为了验证程序的正确性,数值计算了一有升力悬停流场,旋翼桨叶表面压力分布的计算值与实验值吻合很好。

NAVIER-STOKES COMPUTATION FOR A HELICOPTER ROTOR IN FORWARD FLIGHT BASED ON MOVING OVERSET GRIDS

A Navier\|Stokes method based on moving overset grids has been developed to simulate the viscous flow past a helicopter rotor in forward flight. The moving overset grid method is employed to account for the relative motion among the blades which are rotating, cyclically pitching and cyclically flapping. To build the connection among the overset grids quickly, a highly automatic and very efficient method based on Hole Map and Inverse Map is implemented. The cell\|centered finite volume method is used as the spatial discretization method. In order to gain both time accuracy and computational efficiency, a fully implicit method (dual\|time stepping method) has been developed, in which Newton\|like sub\|iterations based on LU\|SSOR scheme are included. Comparison of the numerical results for a lifting hovering case shows good agreement with the experimental data. Although lacking experimental verification, the numerical result of the lifting forward flight case is reliable.