In order to investigate the reason why a patrol boat could not reach its design speed when abroad waterjet propulsion is chosen, CFD method is used to calculate hydrodynamic and cavitation performance of the axial water jet pump.Through analysis of the flow in the pump, it's found that the pump's efficiency is low at the design condition and there are some vortexes and flow separations at the guide vanes and duct.A new pump type is selected and designed through three-dimensional inverse design theory.During the draw of the pump meridional channel, the Bezier curve is used to guarantee the meridional channel smooth.At the same time, the number of rotor blades was increased to suppress the area of low pressure.It's shown that the efficiency of the new pump has been improved to 91.2% after optimization.The new pump has a good resistance to cavitations and the secondary flow behavior in the diffuser is completely eliminated.Based on numerical self propulsion of "hull+duct+pump", the patrol boat reaches its design speed successfully.%针对某新设计高速巡逻艇选型国外某喷泵达不到设计航速的问题,运用CFD方法对该被选喷泵和进水流道内流场进行了数值模拟.结果发现,该喷泵在设计工况下敞水效率较低,导叶处有一定程度的漩涡和流动分离,进水流道背部也存在涡旋.运用泵的三元设计理论,为该巡逻艇的喷水推进泵进行了重新选型和三元设计,在轴面线的绘制过程中使用了贝赛尔曲线,保证了整个轴面线的光滑过渡.同时为了提高抗空化性,增加了叶轮叶片数.数值模拟结果显示,新设计的喷泵效率有了明显提高,设计工况效率可达91.2%,同时泵的低压区较小,保证了泵的抗空化性能,也消除了导叶中的二次流."喷泵+流道+平板船"数值自航结果表明,该巡逻艇在设计工况下达到了设计航速.
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