基于Laplacian算法的汽车外流场畸变网格优化  

Optimization on distortion grid of vehicle external flow field based on Laplacian Algorithm

作　　者：张勇[1,2] 毛凤朝[1] 刘水长 王青妤[1] 潘神功 曾广胜 ZHANG Yong;MAO Feng-zhao;LIU Shui-chang;WANG Qing-yu;PAN Shen-gong;ZENG Guang-sheng(School of Mechanical Engineering,Hunan University of Technology,Zhuzhou 412007,China;State Key Laboratory of Advanced Design and Manufacturing of Automotive Bodies,Hunan University,Changsha 410082,China)

机构地区：[1]湖南工业大学机械工程学院,湖南株洲412007 [2]湖南大学汽车车身先进设计制造国家重点实验室,长沙410082

出　　处：《吉林大学学报（工学版）》2023年第5期1289-1296,共8页Journal of Jilin University:Engineering and Technology Edition

基　　金：湖南省重点研发项目(2022GK2065);湖南省自然科学基金项目(2023JJ50192);湖南省教育厅科学研究重点项目(20A157)。

摘　　要：为实现汽车外流场高精度计算,以某款实际在用简化车模为研究对象,分析畸变网格评价指标基础上,应用综合评价指标探寻网格畸变位置。为防止体网格优化时中心节点偏离而出现的负体积现象,提出了基于边长加权的Laplacian算法,开展畸变网格局部优化仿真计算,并以HD-2实验进行验证。结果表明:车身侧面特征线、前后风挡玻璃与机罩、行李箱盖过渡区域易生成体畸变网格,边长加权Laplacian算法可降低畸变网格数量,风阻系数仿真精度提高3.90%,与风洞实验误差为2.26%。对比粒子图像测速(PIV)实验,车模尾部流场模拟相比优化前更加准确,表明了建立的边长加权Laplacian算法的有效性。In order to realize the high precision simulation of the vehicle external flow field,the grid distortion position is explored on the basis of analyzing the distortion grid quality evaluation criteria,with the simplified car model in actual use as the research object.In order to prevent the negative volume phenomenon caused by the deviation of the center node during the optimization of the volume mesh,the length weighted Laplacian algorithm is proposed to carry out the simulation calculation of the local optimization of the distortion grid,and verified by the test results of HD-2.The results show that the transition areas of the body side feature line,the front windshield and hood,the rear windshield and luggage lid are prone to volumetric grid distortion.The length weighted Laplacian algorithm can reduce the number of distorted grids,increase the simulation accuracy of the drag coefficient by 3.90%,and the error from the wind tunnel test is 2.26%.The simulation of vehicle tail flow field is more accurate than before the optimization compared with the PIV test,which shows the effectiveness of the length weighted Laplacian algorithm.

关 键 词：车辆工程 网格畸变优化 Laplacian算法 CFD仿真精度 风洞实验 

分 类 号：U461.1[机械工程—车辆工程]