基于自由变形技术的汽车除霜风道导流板参数优化

Parameter optimization of vehicle defrosting deflector based on free form deformation

针对汽车除霜风道结构复杂、不易于参数优化等问题,采用自由变形技术,对除霜风道内复杂形状的导流板进行快速参数化。将3块导流板放入晶胞型控制框架中,并选取5个位置的晶格控制点作为变形控制点;采用拉丁超立方试验设计方法构建42组样本,建立高可信度的径向基模型;利用遗传算法对导流板进行寻优,最后对优化后的结果进行数值模拟。研究结果表明:借助自由变形技术能有效改善前挡风玻璃表面A和B区的流场分布并提高对流换热能力,使A区除霜面积达到80%和100%的时间分别提前17 s和40 s,B区除霜面积达到95%的时间提前6 s。由此可见,自由变形技术可用于对除霜风道内复杂形状的导流板进行简单、高效的参数优化。

In order to solve the problem that the complex structure of defrosting duct is hard to parameterize in the optimization of vehicle defrosting performance,a fast and effective parameterization method,i.e,free form deformation(FFD)was adopted.The lattice control points at 5 positions of three deflectors which were put into the cellular control frame,were selected as the deformation control points.Through the Latin hypercube experimental design method,42 groups of samples were constructed,and a highly reliable radial basis approximate model was established.Then,the genetic algorithm was employed to get the optimal model of 3 deflectors.Finally,the optimal model was simulated numerically.The results show that the distribution of flow field and the capacity of convection heat transfer on the A and B zones are improved by using FFD method.Compared to the initial model,the time when the defrost area of A zone reaches 80%and 100%is 17 s and 40 s earlier,and the time when the defrost area of B zone reaches 95%is 6 s earlier by using the FFD method.Thus,FFD can be used to conduct simple and efficient parameterization of the complex shape of the deflector in the defrosting duct.