基于遗传算法的带内流低阻车身气动优化  

Aerodynamic Optimization of Low-drag Vehicle with Internal Flow Based on Genetic Algorithm

作　　者：李启良[1,2] 杜文海 李璇 杨志刚[1,2,3] 陈羽 LI Qiliang;DU Wenhai;LI Xuan;YANG Zhigang;CHEN Yu(Shanghai Automotive Wind Tunnel Center, Tongji University, Shanghai 201804, China;Shanghai Key Lab of Vehicle Aerodynamics and Vehicle Thermal Management Systems, Shanghai 201804, China;Beijing Aeronautical Science ＆ Technology Research Institute, Beijing , 102211, China)

机构地区：[1]同济大学上海地面交通工具风洞中心,上海201804 [2]上海市地面交通工具空气动力与热环境模拟重点实验室,上海201804 [3]北京民用飞机技术研究中心,北京102211

出　　处：《同济大学学报（自然科学版）》2018年第1期94-99,共6页Journal of Tongji University:Natural Science

基　　金：上海市地面交通工具风洞专业技术服务平台(16DZ2290400)

摘　　要：通过建立18个参数的参数化模型,并开发了基于遗传算法的全局优化方法,展开带内流的车身气动优化,获得了气动阻力系数为0.261的低阻优化外形.比较最优车身的仿真和试验结果发现,气动阻力系数仅相差4%,表面压力系数和不同截面速度分布趋势相同、量值相差较小,表明所采用数值仿真方法是正确、可行的.利用本征正交分解对车身尾部截面流场进行能量分解发现,前9阶模态占总能量的54.5%;能量占比最高的1阶模态呈现出尾部拖曳涡的形态,并且拖曳涡的涡核位置不随时间变化而变化.建立了带内流的全局优化方法,获得了经试验验证的带内流低阻车身,为相关产品开发提供借鉴方法和外形参考.A parametric model of 18 parameters was established and a global optimization method based on genetic algorithm was developed. The aerodynamic optimization of the vehicle body with internal flow was carried out and a lowdrag optimization shape with aerodynamic drag coefficient of 0. 261 was obtained. Comparing the results of numerical simulation and test, it is found that the difference in aerodynamic drag coefficient is only 4%. The surface pressure coefficient and different cross-section velocity contours have the same distribution and small difference of magnitude, which indicates that the numerical simulation method is correct and feasible. Through the energy decomposition of the flow field in the tail section using the Proper Orthogonal Decomposition, it can be observed that the first nine modes occupy 54.5 % of the total energy. Among them, the first-order mode with the highest energy shows the shape of the tail drag vortex and its vortex position does not change with time. In this paper, the global optimization method of the vehicle with internal flow was established, and the low-drag model with internal flow was validated by test, which can provide a method and reference for the development of related products.

关 键 词：遗传算法 内流 低阻车身 气动优化 本征正交分解 

分 类 号：U467.1[机械工程—车辆工程]