基于高阶和高效格式的悬停旋翼可压缩无粘绕流的计算

发展了一种基于高精度和高效格式计算悬停旋翼复杂绕流的隐式有限体积方法。控制方程为Euler方程,其中对流项通量的左右状态量采用五阶加权基本无振荡(WENO)格式重构,时间推进应用隐式LU-SGS算法,为进一步加速收敛,采用三层V循环多重网格松弛方法。考虑到多重网格方法的思想以及五阶WENO格式涉及6个网格单元,建议仅在最细网格上使用WENO格式。计算结果表明本文方法能有效捕捉激波,对尾迹也有较高分辨率,基于隐式LU-SGS算法的多重网格方法能有效提高计算效率。

Compressible inviscid flow computation on a hovering rotor based on high order accuracy and high efficiency with schemes

An implicit finite volume method with high-order accuracy and great efficiency is developed to capture complex flow phenomena on a helicopter rotor in hover.A fifth-order Weighted Essentially Non-oscillatory (WENO) is used to reconstruct the left and right states of convective flux of Euler governing equations.To improve efficiency,the use of a class of lower-upper symmetric Gauss-Seidel (LU-SGS) implicit algorithm in conjunction with three-level V-cycle multigrid relaxation schemes is explored.Considering building idea of multigrid and fifth-order WENO scheme involving six cells,it is proposed that WENO scheme is only executed in the finest grid.The results reveal that the present scheme has great capabilities in capturing shock and wake.The multigrid scheme with the implicit LU-SGS method can substantially improve computational efficiency.