用运动嵌套网格方法数值模拟旋翼前飞非定常流场

通过求解Ｅｕｌｅｒ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，本文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。空间采用中心平均的有限体积法进行离散，时间方向采用双时间法隐式推进求解。为了验证方法的正确性，数值模拟了悬停流场，数值结果和实验值吻合很好。尽管前飞状态的计算没有实验验证，但计算结果与其它文献计算结果吻合很好。

Numerical Simulation of Unsteady Flow Around a Helicopter Rotor in Forward Flight Using Moving Overset Grids

A new numerical method has been developed to model the unsteady flow around a helicopter rotor in forward flight using Euler equations. The method accounts for the dynamic motion of the rotor including rotating,cyclic pitching and cyclic flapping through relative grid motion.To bulid the connection among the overset grids quickly,a very efficient method called Moving Overset Grids Method is implemented.The numerical method uses finite volume method in space and advances the solution in time using dual time stepping method. To verify the code based on this method,a hovering flowfield is calculated. Numerical results agree well with experiment.For the forward flight case,although lacking of experimental verification,the numerical results agree well with the data reported in other reference.In addition, the method can be easily extended to model the viscous flow about the rotor in forward flight and the flowfield of the combination of rotor and fuselage.