Numerical Simulation On Hydraulic Characteristics Of Discharge Structure Of Nankang River Hydropower Station

By applying k turbulence model and VOF method, 3-D numerical simulation study was made on the hydraulic characteristics of discharge structure of Nankang River Hydropower Station. This paper focuses on analysis of the flow pattern, flow rate, pressure, head loss and other hydraulic characteristics. According to the calculation results, optimize the shape of discharge structure and study numerical simulation further is necessary. Then the numerical simulation results and physical model test results are compared.Numerical results show that the discharge capacity of original scheme can’t meet design requirement. When the flood recurrence interval is 1000 years, spillway surface appears negative pressure, but it is in reasonable range. No matter whether the hydropower station operates, flow regime of power station intake is good and velocity distribution is uniform. Conclusion is that the shape of overflow weir should be optimized because of the insufficient discharge capacity.In the optimization scheme, the elevation of overflow weir is dropped to 649.5m. The new model have several important modifications at curve segment and upstream of aeration slot. The calculation results show that the discharge capacity of optimization scheme can meet design requirement. When the flood recurrence interval is 1000 years, spillway surface also appears negative pressure, but it is safe enough in operation. Flow regime of power station intake is good and velocity distribution is uniform.