| Technology of numerical simulation in flow field, witch is based on computational fluid dynamics(CFD), is a useful tool to reveal the internal mechanism of turbo machine, and also a effective means for modification and for shorten the developing cycle of turbo machine. Its' the developing trend of computer aided design (CAD) in turbo machine.The main works are as follows:1. Based on a number of documents, the development course of CFD and the application of numerical simulation in centrifugal pump is introduced so as the present deficiency.2. A comparison of different coupling models and different simulating methods were taken. Commercial code Pro-E was employed to build the 3D model of FLG40-200 centrifugal pump, and commercial CFD package Fluent with its preprocessing code GAMBIT was used to generate the grid and to conduct numerical simulation.3. A new convergence criterion was proposed to according to the lack of old criterion. Two pumps were studied with both the new and old convergence criterions and compared, show that the new and old criterions according with each other, but the new one gives a quantitative measure of how stable the flow field is, and steal work in low flow rate of low specific speed pump, when the old one is failure.4. Calculating methods of disc friction and volumetric loss were summarized, and disc friction and volumetric loss correction scheme were determined on it. The correction scheme was used to calculate the performance data of pump from the flow field information of different simulations. In comparison with the experimental data, it was find out that the result of unsteady simulation is better. Then, characteristic curves were drawn. A depth analysis of impeller and volute were also taken.5. Based on the analysis, modification was taken for saving energy. Using unsteady simulation, an exam was also taken place to determine if the modification was successful. It shows that energy was saved, and the necessary head of pump was also reached. |
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