测流孔板数值模拟及流量系数的分析

Numerical stimulation and analysis of discharge coefficient of orifice in conduit to measure discharge

孔板用于压力管道中测量流量,其特点是过流量小、流速低,而资料介绍的孔板流量系数都由模型实验得出.格鲁吉亚卡杜里电站采用跨流域引水方式,其引水道模型实验中采用此测流方法经济实用.本文采用标准k?ε湍流模型对孔板流场进行数值模拟,得到流速分布和流量系数,通过模型实验对低流速孔板的流量系数进行了验证,两者结果完全一致.在上述电站引水道模型试验中采用孔板测流的流量系数,试验结果完全满足精度要求.

The velocity of flow through the orifice plate to measure discharge of conduits is lower than to dissipate energy. The discharge coefficients of orifice introduced in references are determined by experiment. Khadori power station in Georgia with a trans-basin diversion system takes water from two rivers. The method of measuring conduit discharge by orifice is either economic or practical, which is applied in model experiment of diversion system. The numerical model is set up to stimu!ate - orifice by standard k-εTurbulence Model. The discharge coefficient of designed orifice is measured by experiment in this paper. The distribution of velocity and the discharge coefficient of numerical calculation are well fitted with experimental ones. The result of numerical stimulating the orifice verifies that of experiment. The precision of experiment of diversion system of Khadori power station is satisfied to apply the orifice to measure the discharge of conduits.