Study On 3-D Numerical Simulation On Coefficients Of Head Loss Of Surge Chambers

The flow patterns in surge chambers are very complex and the relevant hydraulic parameters of surge chambers have drawn attention of scholars and desingers. The coefficients of head loss of surge chambers, not only affect the magnitude and decay rate of surge, but also play an important role in the analysis of system stability and the reflaction of water-hammer. In the past, the coefficients of head loss were got by means of the hydraulic manual, theoretical analysis or model experiment. With the rapid development of modern computer software and hardware, the technology of CFD has been more widely applicated in the study on three-dimensional flow field of turbulence. What draws the people more interest is how to use the technology to study the hydraulic characteristics of surge chambers.On the basis of the results of predecessors, the FLUENT software has been used as the calculation platform in this paper. By using methods of numerical simulation which includes different turbulence models, gridding methods, discrete formats, iterative algorithms and the conditions of boundary, the coefficients of head loss of the surge chambers of a pumped-storage power station and a conventional hydroper station shared by three units were predicted. In the process of simulation, the methods of free inlet, free outlet boundary and no-slip velocity condition were applicated. Near-wall flow was resolved by wall function. By analysising and comparing the results which were calculated by numerical simulation with model experiments, the feasibility of using numerical simulation as a measure to predict coefficients of head loss of the surge chambers, and to reduce the complexity of the model experiment and periodic time of study were proved. Then, the most suitable methods for the numerical simulation of flow in surge chambers were recommended.