网格质量评价指标对汽车外流场模拟结果影响的研究

摘要

For revealing the influence of multiple mesh quality evaluation criteria on the simulation results of aerodynamic drag and surrounding flow field, the simulation accuracies are analyzed when five different mesh quality evaluation criteria are assured respectively, with the simulation results of surrounding flow field of interna-tional standard notch back MIRA model as reference and verified by the test results of HD-2 wind tunnel in Hunan University. The results show that all criteria of “Quality”, “Aspect Ratio”, “Min Angle”, “Max Orthogls”and“Skew” can meet the engineering accuracy reqirements in aerodynamic drag calculation and wake vortex simulation. Only “Quality” criterion can better simulate the back vortex of MIRA model, but is still not accurate enough in size. So these mean that the mesh quality evaluation criteria currently used still can not well meet the requirements of meticulous analysis on the surrounding flow field of vehicle body.%为揭示多个网格质量评价指标对气动阻力系数和外流场模拟结果的影响，以MIRA阶梯背国际标模外流场模拟结果为参照，以湖南大学HD-2风洞试验结果进行验证，分析了分别保证5项不同的网格质量评价指标时的模拟精度。结果表明：综合评定指标、纵横比指标、最小角指标、最大正交性指标和歪斜率指标对气动阻力系数的计算均能达到工程精度要求，且对汽车尾涡的模拟均较准确，而仅有综合评价指标能较好地模拟出汽车背部涡流，但涡的大小仍不准确。因此，目前所用的网格质量评价指标尚不能完全满足车身周围流场精细分析的要求。