喷水推进泵相似换算模型试验及性能研究

Similarity Conversion Model Test and Performance Study of Water Jet Propulsion Pump

为了探究喷水推进泵外特性性能与推力性能之间的变化规律,基于水力机械流动相似准则设计得到与原型泵相似的模型泵叶轮,在此基础上开展模型泵的外特性试验并换算得到原型泵的外特性曲线。同时,基于CFX商业软件对喷水推进泵全三维数值计算进行求解,探究不同湍流模型下的数值计算结果和不同转速工况下能量系数KE的变化规律以表征泵的推力性能。结果表明:标准k-ε湍流模型的外特性计算结果与试验结果偏差不超过4.5%,数值计算方法可靠;能量系数KE随流量变化规律与泵效率η相似,但最优工况点存在明显偏差;对于模型泵,其最优推力效率点出现在1 600 r/min附近,这与推力的数值计算结果相一致。由此可推断,采用能量系数KE表征泵的推力特性具有一定的可行性,该方法对于喷水推进泵的设计与优化具有参考价值。

In order to explore the change law between the external characteristic performance and thrust performance of the water jet propulsion pump,a model pump impeller similar to the prototype pump is designed based on the hydraulic machinery flow similarity criterion.On this basis,the external characteristic test of the model pump is carried out and the external characteristic curve of the prototype pump is obtained by conversion.At the same time,based on commercial software CFX,the full three-dimensional numerical calculation of the water jet pump is carried out to explore the numerical calculation results under different turbulence models and the change law of the energy coefficient KE under different pump rotation speed conditions to characterize the thrust performance of the pump.The results show that the deviation between the calculation results of the external characteristics of the standard k-ε turbulence model and the test results does not exceed 4.5%,and the numerical calculation method is reliable.The change law of energy coefficient KE with flow is similar to pump efficiency η,but there is a significant deviation at the optimal operating point.For the model pump,the optimal thrust efficiency point appears near 1 600 r/min,which is consistent with the numerical calculation results of thrust.It can be inferred that it is feasible to use the energy coefficient KE to characterize the thrust characteristics of the pump.The method has reference values for the design and optimization of water jet propulsion pumps.