混合重叠网格插值方法的改进及应用

An improved interpolation method for hybrid overset grid and its application

混合重叠网格间合理插值是保证流场计算正确的基础之一。本文针对重叠区网格尺寸匹配度较差时插值误差较大问题,发展了一种新型混合重叠网格插值方法,通过使用二阶精度插值、按单元尺度区分和扩充模板,改善了插值区网格尺寸匹配度较差时的插值精度。本文方法适用于任意单元类型的混合网格重叠,对各类单元处理透明,实现简单。计算结果表明,采用本文方法在网格重叠区流场变量传递正确有效,插值区网格尺寸匹配度较差时,相比原始方法,等值线过渡更为光滑,变量经过插值区耗散更小,计算与试验值符合更好。

For overset grid,reasonable interpolation between grids is one of the bases to ensure correct calculation of flow fields.In this paper,a new interpolation method for hybrid overset grid is presented,which focuses on the elimination of interpolation error coming from the grids mismatch at the intergrid boundary.With the combination of second order accuracy interpolation and proper selection and expansion of interpolation template by grid size,the interpolating accuracy of the cases with poor overset grids matching is improved.The presented method is suitable for arbitrary polyhedral grid and easy to be implemented.Compared with original method,numerical tests show that the presented method interpolates flow field variables with less dissipation when bad grids matching happened at the intergrid boundary,the variable contour at the intergrid boundary is smoother,and computational results agree more with the experimental data.