网格质量反馈的弹性体动网格改进

摘要

高鲁棒性的动网格变形方法是求解包含运动边界的非定常流场问题的关键技术.基于经典的弹性体动网格方法,引入两种设计合理、评价效果较好的网格质量参数——Patrick参数和Baker参数,提出了一种基于网格质量反馈的改进弹性体动网格方法.结合二维NACA0012翼型、三维ONERA M6机翼大角度俯仰运动,对比研究改进方法与经典方法的变形能力,改进方法能够保持较好的网格质量,尤其在最大变形时,可以有效改善较差网格单元,具有更高的鲁棒性.计算了NACA0012翼型、ONERA M6机翼的俯仰振荡绕流,并与实验结果及文献进行对比,结果表明,基于网格质量反馈的改进弹性体法能够显著提高变形网格的鲁棒性,可为非定常流场问题的求解提供有力支撑.%Dynamic grid deformation method with higher robustness is critical for unsteady flow problems which include moving boundaries. Two of rational and effective mesh quality parameters were introduced,namely Patrick parameters and Baker parameters.Then,a modified dynamic grid method was presented, which can optimize mesh quality on term of mesh quality feedback.Combined with large-pitching of 2D NACA0012 airfoil and 3D ONERA M6 wing, the difference between modified method and classical method was fully analyzed.Modified method has obvious advantage in mesh quality,and at the largest moving degree,it can significantly enhance the robustness of grid mainly through perfecting the worse element.Finally,the modified method was applied to simulate the pitching motion of NACA0012 airfoil and ONERA M6 wing,and the calculations were compared with the experimental values and literature.Result shows that the modified method can improve stronger robustness,therefore it can provide better support for unsteady flow problems.