U型节流槽气穴流仿真分析及多目标优化

Simulation Analysis and Multi-objective Optimization of Cavitation Flow in U-Shaped Throttling Groove

利用流场仿真软件对不同开度下的U型节流槽气穴进行仿真分析。通过改变U型节流槽的槽宽B、槽深H、槽长L,讨论了3个参数对气穴体积和气蚀指数σ_(A_(im))的影响。采用正交试验设计方法得到3个结构参数的试验方案,共计16组,利用Kriging曲面插值法求得在3个因素尺寸范围内的所有试验结果,再利用多目标优化算法NSGA-Ⅱ来减小气穴体积和气蚀指数从而实现多目标优化。数值仿真验证结果表明,优化后的U型节流槽结构能够减小气穴体积和气蚀指数。

Having the flow field simulation software used to simulate cavitation of U-shaped throttling groove with different opening degrees was implemented.Through changing structural parameters of the U-shaped throttling groove,such as groove width B,groove depth H and groove length L,the influences of these three parameters on both cavitation volume and cavitation indexσ_(A_(im))were discussed,including having orthogonal experimental design method used to obtain the test scheme of three structural parameters selected,a total of 16 groups;meanwhile,having Kriging surface interpolation method employed to obtain all test data within size range of the three factors was implemented,including having multi-objective optimization algorithm NSGA-Ⅱused to reduce both cavitation volume and cavitation indexσ_(A_(im))so as to realize the multi-objective optimization.The results show that,the optimized U-shaped groove structure can reduce both cavitation volume and cavitation indexσ_(A_(im)).