中文摘要：

在旋转坐标系下,将Spalart-Allmaras（S-A）一方程湍流模型和Reynolds-averaged NavierStokes（RANS）方程耦合成一个新的RANS方程,并发展了基于多块重叠网格的强耦合RANS求解方法,用于直升机旋翼悬停流场的数值模拟.为了提高计算效率,针对多重网格方法在多块重叠网格上实施的困难,提出了一种基于重叠网格的多重网格实施方法.通过对Caradonna-Tung（C-T）和ONERA 7A旋翼悬停算例验证了发展的强耦合RANS方法和基于重叠网格的多重网格实施方法的有效性.研究结果表明：发展的基于重叠网格的多重网格方法有较高的计算效率,3层网格的加速比约为7.7;强耦合RANS法的计算精度明显高于传统的松耦合RANS方法,特别是在与阻力相关性能参数的预测中,强耦合RANS方法的预测结果更加精确.

英文摘要：

In the rotating coordinate system, Reynolds-averaged Navier-Stokes （RANS） equations and Spalart-Allmaras （S-A） equation model were coupled as a new strongly coupled RANS equation, then a strongly coupled RANS algorithm based on overlap grids was proposed and applied to simulate helicopter rotors viscous flow in hover. In order to improve efficiency, a new implementation method of multigrid algorithm based on overset grids was proposed for solving the difficulty of implementation in chimera grids system. The effective- ness of strongly coupled RANS method and the proposal of multigrid algorithm based on chimera grids was verified using Caradonna-Tung （C-T） and ONERA 7A hover test cases. The results show that the proposal of multigrid algorithm based on overlap grids has much higherefficiency, and the speed up ratio of three-level multigrid is about 7.7; the accuracy of strongly coupled RANS algorithm is super higher than loosely coupled RANS algorithm, especially in the prediction of performance parameters relevant to drag force.