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Water jet propulsion is a special method of propulsion , has been widely used in high-performance ships . Jet Propulsion pump as the water jet propulsion system body , compared with the average pump flowing capacity , pump efficiency , cavitation resistance and structure have higher requirements . Therefore , the design of a high flow, high efficiency and anti- cavitation performance good water jet propulsion pump there is an urgent need to address the problem . This article is based on two types of relative flow surface theory , given the shaft surface shape of the flow channel based on velocity moment distribution and leaf thickness distribution of the known conditions , the application of singularity distribution method waterjet pump quasi - three-dimensional inverse problem optimize the design , and Fortran programming language to implement this process . Completion of the water jet propulsion pump three-dimensional modeling , and application of computational fluid software Fluent their internal flow field numerical simulation calculations . According to the calculation results to estimate the pump head , efficiency , shaft power , external characteristics , distribution and analysis of pump internal pressure , velocity vector distribution master pump flow , forecasting easy cavitation region . The design process of the inverse problem , the design of the blade to try a variety of programs , including change of torque distributed manner along the axial flow line speed , the flow angle of the blade inlet , the maximum position of the blade thickness . Calculated by numerical simulation , and analysis of the pros and cons of these programs , and ultimately determined to meet the design requirements of the leaf type . The results show that : (1) control the speed of the blades moment distribution , can effectively control the load distribution of the blade , to a certain extent to ensure the pump cavitation resistance . ( 2) blade inlet liquid flow angle pump performance a great influence , according to the design point , select the appropriate flow angle to ensure efficiency at the same time can have a good anti-cavitation . (3) The calculation shows that the maximum thickness of the blade position different for certain anti-cavitation pump . Maximum thickness position right amount of backward , help to improve the anti- cavitation performance of the pump . (4 ) different the blade inlet side location of the structure and performance of the pump also has changed dramatically . Comparative calculation of the different programs provide a strong basis for the improved design of the pump . Finally , according to the calculation of the previous analysis to determine the final design of the pump , to improve the speed and calculate the predicted performance of the pump through the flow field .
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