Analysis on Discharge Coefficient of Emptying Tunnel Combined with Diversion Tunnel of Hydropower Station

Hydraulic model test were done for flow capacitying of reservoir emptying tunnel combined with diversion tunnel of high head development.We adopted CFD software fluent to carry out numerical simulations,calculated,and analyzed discharge coefficient of pressure stage export cross-section of emptying tunnel.Comparative analysis results of physical model test and numerical simulation show that correspond different water level Reynolds number of digital analogy and physical simulation of pressure cross-section of the emptying tunnel increase with the rising of water lever,the increase is roughly the same as linear trend.The former discharge coefficient is 0.884-0.897,the latter is 0.902-0.904,a biggest absolute deviation is 0.02.The two results are coincide visibly.Suitable slope gradient is benefit to increasing flux.