基于正交设计的扭曲鼻坎体型优化试验研究

Experimental study on shape optimization of skew bucket based on orthogonal design

挑坎体型对水舌形态和下游河床冲刷至关重要,基于水工模型试验,利用正交试验设计对纳子峡工程泄洪洞扭曲鼻坎体型进行优化研究。采用极差分析和方差分析,选取最大冲坑深度、冲刷最低点到边坡的距离、左侧挑距、右侧挑距和水舌宽度作为评价指标对扭曲鼻坎左侧边墙向右偏移距离、右侧边墙向右偏移距离、鼻坎扭曲程度系数3个因素进行计算,分析各因素对评价指标的敏感性,以确立扭曲鼻坎的最优体型。结果表明,各水力学特性指标对左侧边墙向右岸的偏移量的变化更敏感,其余因素对扭曲挑坎的消能效果影响较小,通过正交设计分析所得的最优体型,其水力特性指标均明显优于其他方案,所得成果可为实际工程扭曲鼻坎体型的设计提供依据。

The shape of a flip bucket is very important for the shape of the water tongue and the scouring of the downstream riverbed.Based on the hydraulic model test,optimizing the shape of the skew bucket of the Nazixia spillway tunnel by orthogonal design.Using extreme difference analysis and variance analysis,the maximum crater depth,the distance from the lowest point to the slope,the left jet trajectory length,the right jet trajectory length and nappe width were selected as the evaluation indicators for the offset of the left and right side walls of the skew bucket.The three factors of the degree of distortion of the nose were calculated,and the sensitivity of each factor to the evaluation index was analyzed to establish the optimal flip bucket form of the skew bucket.The results showed that the hydraulic characteristics were more sensitive to the change of the offset of the left side wall to the right bank.The other factors had little effect on the energy dissipation effect of the skew bucket.The optimal shape was also analyzed by orthogonal design.The hydraulic characteristics were superior to other schemes,while the obtained results could provide a basis for the design of the actual engineering skew bucket.