用隐式WENO格式计算悬停旋翼跨声速流场

Numerical simulation on the flowfield of transonic hovering rotor using implicit WENO schemes

发展了一种基于高阶迎风格式的计算悬停旋翼跨声速流场的隐式有限体积法。对流项采用Roe通量差分分裂格式,使用五阶WENO格式进行左右状态重构,并与MUSCL插值进行比较;粘性项采用中心有限体积法。为提高收敛到定常解的效率,时间推进采用LU-SGS隐式方法。数值模拟采用了一种能够有效传递网格间流场信息的重叠网格,其中使用了三层内边界和贡献边界的方法以便插值的直接进行。用该方法对一跨声速悬停旋翼粘性流场进行了数值计算,数值结果表明:与MUSCL格式相比,WENO格式对激波位置捕捉得更准确,具有更强的涡捕捉能力,同时还表明了WENO格式在很大程度上能够克服涡耗散问题。

In this paper,a high-order upwind scheme has been developed to compute the flow field of a helicopter rotor in hover using implicit finite volume method.Roe＇s Riemann solver which is a high-resolution scheme and a flux-difference splitting scheme is adopted to compute inviscid flux.For better accuracy,fifth-order weighted essentially non-oscillatory（WENO） schemes are adopted to interpolate higher order left and right states across a cell interface,and compared with MUSCL schemes.To improve the efficiency and convergence to steady state,the LU-SGS implicit algorithm is used.The aerodynamic field is computed by solving equations on a system of overset grids between which flow field information can effectively exchange.Three layers of inner boundary and contribution boundary are searched in overset grids.The performance of the schemes is investigated in a transonic flow around hovering rotor.The results reveal that WENO schemes attain more exact shock position than MUSCL,and WENO schemes can capture tip vortex with lower numerical dissipation than MUSCL.