船舶喷水推进器推力分布研究

Research on thrust distribution of marine waterjet

应用计算流体力学方法对一典型内置推力轴承混流式喷水推进器的流场进行了数值模拟,计算和分析了叶轮、导叶体、进水流道等主要水力部件的推力分布。计算结果显示:(1)在推进特性线上的设计工况,内置推力轴承上的推力约为喷水推进器净推力(合力)的1.5倍,泵静止部件上的推力约为净推力的-0.5倍,进水流道上的推力很小,可忽略不计;(2)各部件上的推力占净推力的比例在推进特性线上的其它工况基本维持不变;(3)在非推进特性线上的工况,各部件上的推力分布不同于推进特性线上的工况,来流速度与泵转速的比值越高时泵静止部件上向后的推力越大,进水流道上的推力不再是可忽略的小量了。喷水推进器推力分布规律的研究结果可为喷水推进器和船尾结构的强度设计时加载水动力作用项提供参考。

The flow of a typical mixed-flow waterjet with thrust bearing imbedded was simulated by means of computational fluid dynamics（CFD） code in order to investigate its thrust distribution on each compo-nents.Some conclusions are drawn from the calculation results：（1） The thrust fraction on waterjet compo-nents is almost constant in different operating conditions along propulsive performance curve.（2） In the op-erating conditions along the propulsive performance curve the thrust fractions of thrust-bearing and stator-bowl are approximately equal to 1.5 and-0.5 respectively;and the thrust on inlet duct is ignorable.（3） When the operating conditions deviate from the propulsive performance curve,the thrust distribution char-acteristics are changed.Both the positive thrust fraction on thrust-bearing and the negative thrust fraction on stator-bowl increase along with the ratio of ship velocity to pump speed,and the thrust on inlet duct ris-es gradually to a significant magnitude.These conclusions can be referenced to determine the hydraulic load during finite element analysis of waterjet and stern hull.