Design Optimization Of Pumping Station Forebay Based On The CFD Numerical Simulation

Pumping station is the hub of water supply and drainage system. Forebay, is an important part of the pumping station, flow pattern of which plays a vital role for the safety and efficient operation.In this thesis, the numerical simulation was carried out in two steps, firstly three-dimensional model of the forebay was built up based on GAMBIT, in which, the unstructured grid were built up. Secondly, taking the FLUENT as the numerical simulation software, the standard k-ε turbulent model was used to established the numerical model, in which the equations were solved by using SIMPLE algorithm. The numerical model was verified by the experimental data from the field tests in the forebay of the pumping station in North Pudong Road in Shanghai.Aiming at the maximizing the uniformity of velocity of the suction pipe, this thesis conducted a number of three-dimension numerical simulations by changing the suction pipe layout,the water intake pipe location and the forebay’s shape. Both the suction pipe layout of the square tank and the arc tank were simulated. The results show that, the structure sizes of suction pipe have a great effect on the flow pattern and the suction pipe velocity uniformity, only the appropriate structure size can ensure the uniform velocity distribution. The best range of the square tank(including suction pipe space, back wall distance, suspension height and lateral wall distance) and the arc tank(including lateral wall distance and suspension height) is obtained then. Two schemes of the inflow including the front inflow and the side-inlet were simulated. The results show that, the position, scope and intensity of the vortexes vary with the location of the water intake pipe, the effects on the hydraulic performance of pump are different. The appropriate scheme is achieved then. The relationship between the diffusion angle and the length of forebay was studied then. The results show that, different diffusion angles have the best corresponding length of the non-diffuser, the empirical formula on the diffusion angle and the length of forebay was put forward.The results of this thesis can provide a reference and technical support for the future pumping station engineering design, and it is useful in the promotion of the pumping station engineering design.