The Finite Element Analysis And Optimization Design On The Work Surface Of Centrifugal Pump Impeller

With the development of the industry, the application of the pump is is expanding gradually. It is becoming more strict in hydraulic performance and operation stability. The impeller, as a major flowing-through parts, whose working performance and efficiency are playing a vital part in the working performance of the centrifugal pump. On the other hand, the impellers are involved in the complicated combination of the centrifugal force and water pressure. The numerical simulation and finite-element analysis are extensively used in the hydraulic machinery, which is reasonable to take the place of the traditional designing methods for their over-loaded work and low-efficiency.On the basis of a medium-top special pump ,the thesis discussed the flow field simulation in the impeller, static analysis with ANSYS about the impeller and geometric parameters optimization of the impeller. Firstly, a physical model was modeled by the UG, gridded in the Gambit. Using the Computational Fluid Dynamics(CFD) technology, distribution such as pressure, velocity and surface pressure on the surface of the blade was obtained about the impeller of the centrifugal pump. The static analysis and model analysis are performed by using ANSYS. At last, geometric parameters of the impeller were optimized by GA(Genetic Algorithm) ToolBoxes.Under the help of the formdrawing of the centrifugal pump, three-dimensional physical model of the impeller was modeled. The surfaces analysis of the impeller blade was made with the surfaces tool of the UG . The impeller modeling become more reasonable and accurated as well as more high-efficiently in designing.Theories and methods about the interior flow numerical simulation of the centrifugal pump were discussed and some researches were made to mesh and set the boundaries of the impeller in the thesis. The interior flow fields were simulated by the Fluent software under full-work condition of the centrifugal pump, which was contributed to the précised distributions including pressure and velocity of the interior flow and exporting the surfaces pressure data distributing the blades. At present, there rarely is researches involved in the strength and modal analysis which use the water as the medium. After the interior flow fields simulation, the APDL program language based on ANSYS was chosen to get the surfaces pressure date loaded on the blades successfully,obtain stress, strain and frequency characteristics of impeller with the water pressure and centrifugal force,the results show that the operation is reliable under the design condition.To minimize the energy loss, a single-objective function, including disc friction, hydraulic loss and bulk loss, was established and compiled to M-files with the Matlab M-file compiler. As finishing setting a reasonable variables range, the inlet and outlet vane setting angles as well as outlet blade width were optimized by the GA toolboxes based on the Matlab. According to the back calculation with the optimized parameters of the impeller, the efficiency of the centrifugal pump largely increased than before by 2.3 percent.In the thesis, numerical simulation and finite-element analysis were applied to physical design and analysis of the impeller. It is significant and constructive to better the security and reliability of the impeller, shorten the design cycle and reduce the cost.