基于CFD的喷水推进器流道与喷口优化

CFD-based Optimization of Duct and Nozzle in Waterjet Propulsion System

为提高喷水推进器的水动力性能,对喷水推进器的流道与喷口进行了基于数值计算的优化研究。对一台喷水推进泵模型进行了敞水性能数值计算,验证了数值计算方法的准确性和有效性。对喷水推进器流道以及喷口进行参数化的几何重构和优化计算,考察流道与喷口参数对推进性能的影响。研究结果表明:在设计航速下,优化后的喷水推进器的转矩基本没变,推力和效率分别提高了2.53%和2.45%;在全航速范围,推力和效率平均分别提高了2.45%和2.49%。喷口变化对喷水推进器性能的影响大于流道变化对其的影响。适当增加流道倾角和降低导流帽倾角可提高推进性能。降低导流帽的倾角还可减弱导叶处的流动分离,改善导叶附近的流场。

In order to improve the hydrodynamic performance of the waterjet system,the duct and nozzle in the system are optimized based on computational fluid dynamics technology.Firstly,the open water performance of a waterjet pump is simulated,and accuracy of the numerical method is verified by comparing with experimental results.Then parameterized geometric reconstruction of the duct and nozzle is carried out.Results show that the torque of the waterjet system is basically not increased,and the thrust and efficiency are increased by 2.53% and 2.45% respectively at the design speed,and increased 2.45% and 2.49% respectively in average in the range of sailing speed.The influence of the nozzle on the propulsion performance is greater than that of the duct.Propulsion performance can be improved by properly increasing the angle of the duct and reducing the angle of the hub.Reduction of the hub angle may reduce flow separation and improve the flow field near the guide vane.