旋流排沙渠道体型优化的正交数值试验方法和应用

为优化多泥沙河流引水渠道内的泥沙级配，实现泥沙分选的效果，提出了一种新型旋流排沙渠道。基于数值模拟与模型试验结果，采用正交数值试验方法，以分流比与排沙洞典型断面的流速为目标函数，优化了旋流排沙渠道的关键体型参数，对比分析了体型优化前后旋流排沙渠道的水沙特性。结果表明，正交数值试验设计能有效提升结构的优化效率，获得具有良好性能的旋流排沙渠道。当渠道来流量为30 L·s^-1时，优化体型的排沙耗水量较原体型减小21.5%，分流比减小4.6%，排沙洞出口断面最大流速增大10.8%，水流的挟沙能力增强，在排沙洞内形成更有利于泥沙运动的旋转水流条件；体型优化前后的旋流排沙渠道对粒径为0.075～3.0 mm泥沙的总体截沙率分别高达90%和88%，表明旋流排沙渠道具有良好的排沙特性，且优化体型排沙洞内的泥沙淤积量较原体型减小61.8%。本成果可为这种新型旋流排沙渠道体型优化和其在引水渠道等工程中的应用提供参考。

Orthogonal numerical experiment method and application for shape optimization of desilting channel with swirling flow

A new type of desilting channel with swirling flows is developed to optimize the gradation of sediment for water diversion from a heavy sediment-laden river and to improve its sediment sorting effect. Based on the orthogonal experimental design, its key parameters are optimized by combining numerical simulations and model tests, using objective functions of the flow diverting ratio and average flow velocity in the sediment transport pipe; its hydraulic characteristics and desilting characteristics before and after shape optimization are compared and analyzed. The results show that the approach of orthogonal experimental design and numerical simulation effectively improves the optimization efficiency of the channel structure and achieves a good performance of the swirling flows. When the shape-optimized channel has an inflow of 30 L?s-1, the sediment pipe has an outflow reduced by 21.5% relative to the original shape and a diverting ratio reduced by 4.6%. Its maximum outflow velocity is increased by 10.8%, enhancing its sediment carrying capacity, and a rotating flow condition more conducive to its sediment movement is formed. For the desilting channel with swirling flows carrying sediment with the particle size of 0.075 - 3.0 mm, its overall sediment interception rate is as high as 90% and 88% before and after the shape optimization respectively, indicating it has good sediment desilting characteristics; sediment deposition in the optimized transport pipe is 61.8% lower than that of the original shape. The results help optimize the shape of desilting channels and make use of swirling flows for water diversion projects.