Based On The Minimum Energy Dissipation Rate Theory In Flow Calculation And Optimization Of The Bend Of Intake Channel

Pumping station project has played a crucial role in flood control, irrigation, drainage and water transfer, which also has produced great economic benefits and social benefit. Intake channel and forebay is taken as an important component part of the pumping station,of which the reasonable hydraulic design can ensure water flow smoothly and stability and create a better flow pattern for the pump. It also has a great effect on improving the energy performance and pump device cavitation performanceThis paper based on the minimum energy dissipation rate theory,at first it took the minimum energy dissipation rate as objective function,bottom width,average section water depth and slope coefficient as design variables and the boundary conditions and flow characteristics as constraint then established the mathematical model. Finally, by the genetic algorithm obtained optimization design for section parameters of the bend of intake channel.Moreover,through the changing of design variables, when bottom width, slope coefficient, water depth,any variables is known respectively, optimizing the other three parameters, and get the optimal variable cross-section design parameters.Through the contrast test of the two situation,verifying the a section of the correctness of the parameters optimization.CFD technology, namely computational fluid dynamics technology, gets rapid development with the enhancement of computer performance and the improvement of numerical method. Now as a kind of the CFD software which has the most comprehensive function and extensive practicability, the FLUENT software is spreading gradually in the hydraulic engineering. In order to further analysis the flow pattern of intake channel corner and forebay,of which the section is optimized.With the aid of the pretreatment software of FLUENT, based on Navier-Stokes equations and the RNG k-ε turbulent model,choose corresponding optimization section and establish three-dimensional entity model. And in the process of mesh generation, local refinement was done to improve the quality of the grid. Given reasonable boundary condition, applied SIMPLE algorithm, numerical simulation was obtained. Numerical simulation results show that based on the minimum energy dissipation rate theory,the design section parameter of the bend of intake channel is rational credible.Meanwhile, according to streamlined diagram of forebay, inlet conduit section of the velocity distribution and uniformity,it is found that the energy dissipation rate and velocity distribution has no established relationship. But deviation and backflow of the forebay of the pumping station still exist.In order to improve the flow pattern of forebay, the diversion pier is applied as engineering measures. It is found that after joining diversion pier, the large-size eddy before arc wing wall of forebay had greatly reduced, the water more evenly flows into the forebay,which meets the requirements of pump uniform requirements, improve the efficiency of the pumping station. This paper provides a reference method in designing intake channel corner.