基于凹坑型非光滑结构的车身气动减阻优化方法研究
Optimizing Strategy on Car Body Aerodynamic Drag Reduction Based on Pit-type Non-smooth Structure

采用了梯度优化法和全局优化法对凹坑型非光滑单元进行优化设计,寻求非光滑单元对汽车的最佳气动减阻效果。将凹坑型非光滑结构布置在某款集装箱货车模型的不同位置,比较减阻效果差异,确定了模型的有效减阻位置。以凹坑单元体开口直径、深度、纵向间距、横向间距为设计变量,分别采用梯度优化法和全局优化法优化凹坑型非光滑结构,比较了两种方法的差异。结果表明:梯度优化法可以快速得到适用于工程实际的优化方案;全局优化法考虑到了变量的耦合因素,优化结果更加全面、准确;经过优化,凹坑型非光滑结构可有效减小气动阻力达10.44%。
This paper uses gradient optimization method and global optimization method to optimize the design of the pit-type non-smooth unit, seeking the best drag reduction effect on the car body by adding non-smooth structures. The pit-type non-smooth structure is arranged on different locations of a container truck model, the difference in drag reduction effect is compared to determine the effective drag reduction position of the model. The pit-type non-smooth structure's design variables of aperture diameter, depth, vertical spacing, and horizontal spacing were optimized using the gradient method and the global optimization method respectively; the differences between the two methods were compared. The results and their discussion show preliminarily that: the gradient method can quickly obtain optimization program for practical engineering; global optimization method takes the variable coupling factor into account and its optimization results are more comprehensive and accurate; after optimization, pit-type non-smooth structure can effectively reduce the aerodynamic drag up to 10.44%