聚合多重网格法在旋翼前飞流场计算中的应用

Application of agglomeration multigrid method in calculation of rotor forward flight flow

基于非结构动态嵌套网格,将聚合多重网格方法引入到旋翼的前飞流场计算中.从初始的整体非结构网格出发,快速建立相互重叠的两个子域网格,同时无需建立背景网格便可以确定初始洞边界和初始插值贡献单元,且动态嵌套时无需更新洞边界,并采用了一种无需背景网格便可快速查找新的贡献单元的方法.分区利用聚合法生成多重网格,利用双时间方法分区运用三层网格V循环求解非定常Euler方程,两区的流场参数在重叠区实现耦合,对旋翼的前飞流场进行了计算.结果表明,多重网格方法能够有效地加快旋翼前飞流场收敛.

An agglomeration multigrid method was applied to numerical calculation of rotor forward flight flow based upon the unstructured dynamic overset grids. Two overlapping subareas could be generated speedily from original global unstructured mesh, while the original hole fringe and donor elements could be established without using a background grid. And, the hole fringe needn＇t update during dynamic oversetting, and the new donor el- ements could be searched quickly by using a new technique without background grid. The agglomeration multigrids were generated separately in each subarea, and a three-level V cycle method was used to solve the unsteady Euler equations by dual time stepping. The flow field parameters were coupled in the overlapping area. Finally, the rotor forward flight flow was calculated. The results show that, the agglomeration multigrid method can facilitate the convergence of rotor forward flight flow effectively.