单人水下用螺旋斜流式喷水推进泵设计及性能预测

Design and performance prediction of screw mixed-flow water-jet propulsive pump for individual underwater utilization

基于动量定理,采用速度系数法设计一种直流电机驱动的单人水下用螺旋斜流式喷水推进泵.为进一步了解推进泵运行情况,基于多重参考系下的雷诺时均N-S方程和RNGk-ε湍流模型,对推进泵的内部流动进行全三维数值计算,获得了推进泵的部分内部流场信息以及效率和功率特性曲线.分析所得信息和曲线可知,推进泵偏大流量工况运行时导叶内部流动相对稳定;推进泵无喷出段时效率比有喷出段时高,设计点高出约32%;随着推进速度的增大,推进泵的有效输出功率先增大后减小,制动功率成三次方增大,当推进速度增大到2.6m/s时,推进器受力达到平衡状态,推进速度不再增大.总体而言,推进器结构设计合理,水力性能较好,推进作用能够实现,但推进效率(最优工况效率仅为57.88%)偏低,还需进一步改进.

Based on momentum theorem,a screw mixed-flow water-jet propulsion pump driven by direct current motor was designed by using velocity-coefficient method for individual underwater utilization.In order to further understand its operational condition,full-three-dimensional numerical computation of interior flow of the pump was conducted on the basis of Reynolds time-averaged Navier-Stokes equations and RNGk-εturbulence mode in multiple reference frames and partial interior flow field information and power and efficiency curves of the pump were obtained.It could be known by analyzing the obtained information and curves that the internal flow around spatial guide vanes would be more stable when the pump worked under a partially larger flow condition.The efficiency of pump without a nozzle would be higher than that with a nozzle and about 32% higher at the design regime point.The pump braking power would increase in cubic order and the effective output power would increase at first and then decreases with the increase of propulsion speed.The stress on the propulsor would achieve its equilibrium condition when the propulsion speed reached about 2.6 m/s and the output power would not increase any more.Overall speaking,the structural design of the propulsor is rational,its hydraulic performance is better,and the propulsion function can be realized.However its propulsive efficiency is a little bit low（only 57.88% under optimal working regime）,so that it needs to be further improved.