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发展了一种基于高阶迎风格式和嵌套网格捕捉直升机悬停旋翼涡尾迹的方法.无粘通量采用Roe Reimann求解器,使用改进的5阶加权基本无振荡(WENO)格式对交界面左右状态进行高阶插值,并与MUSCL插值进行比较.为便于捕捉尾迹和实施周期性边界条件,计算采用结构嵌套网格,其中高质量的旋翼网格完全嵌套于背景网格中.当解达到近似收敛后在桨尖涡分布区域对背景网格进行加密,如此经过3次得到优化的背景网格.考虑到WENO格式插值的特点,提出了搜索3层洞边界和人工外边界的方法以便插值的直接进行.用该方法对一跨音速和一亚音速悬停旋翼粘性流场进行了数值计算.数值结果表明:所发展方法对涡尾迹具有很高的捕捉能力;与MUSCL格式相比,WENO格式具有较低的数值耗散.
A new method to capture helicopter hovering vortex trail based on a high-order upwind scheme and a nested grid is developed. The non-stick flux is modeled using a Roe Reimann solver and a modified WENO The left and right states are subjected to higher-order interpolation and compared with the MUSCL interpolation.For the convenience of tracing the wake and implementing the periodic boundary conditions, the calculation uses a structured nested grid in which a high-quality rotor grid is completely nested in the background grid After the approximate convergence is reached, the background grid is encrypted in the tip vortex distribution area, and the optimized background grid is obtained after three times.According to the characteristics of WENO format interpolation, a method of searching 3-layer hole boundaries and artificial external boundaries The numerical results show that the developed method has a high ability to capture vortex trails. Compared with the MUSCL format , WENO format has lower numerical dissipation.