过水建筑物变态模型水流相似性试验研究

Experimental Study on the Flow Similarity of Distorted Models of an Overflow Structure

参照黄河山东齐河河段北展分凌(洪)区豆腐窝分洪闸进行了模型设计和试验.依据实体模型相似理论,结合河道模型设计经验,选定变率分别为1.0、3.0、5.0、8.0、10.0、13.3的6个概化模型.对5个变态模型和1个正态模型的泄流能力、闸上游流场进行了试验对比研究.试验结果表明:变态系列模型垂线平均流速沿断面宽度的分布与正态模型一样,不同变率模型各断面平均流速与正态模型流速的偏离程度不大;流量系数与变率大小无明显规律,变态模型的流量系数比正态模型增大约0.06~0.22倍;建立了各变态模型的相对水头与流量系数m的表达式.

In this study,model design and testing are performed based on the Doufuwo flood diversion gate in the Qihe reach of the Yellow River in Shandong Province.Based on the similarity theory of the hydraulic model and experience of river model design,six generalized models with variable rates of 1.0,3.0,5.0,8.0,10.0 and 13.3 are selected.Subsequently,the discharge capacity and flow field distribution of five distorted models and one normal model are experimentally compared.Experimental results revealed that the vertical average velocity distribution along the cross-section of the distorted models is the same as that of the normal model;moreover,there was a slight deviation between the average velocity of each section of the distorted models and the normal model.The flow coefficients of the distorted models were approximately 0.06-0.22 times greater than that of the normal model.Thus,the expressions of relative head and flow coefficient m of each distorted model are established.