喷水推进器空化限制线制定方法

A method of determining cavitation limit lines for a marine waterjet

以某典型船用喷水推进器为研究对象,根据其性能曲线和喷水推进理论,归纳出关于制定空化限制线的正、反问题以及制定空化限制线的思路;通过数值模拟与分析,验证了该思路的可行性,并确定了空化限制线制定方法。数值计算结果与试验数据对比表明:建立的数值模型和计算结果是可信的;空化限制线Ⅰ、Ⅱ、Ⅲ分别对应扬程下降量的1%、2%和20%,证实了空化限制线即为等汽蚀比转速线的结论。根据此方法,可以制定船用喷水推进器的空化限制线,实现其完整推进性能曲线图的绘制,指导喷水推进器的安全运行。

With a typical marine waterjet as an object of study, a method to deal with the position and negative problems of determining cavitation limit line is proposed according to its propulsion performance graph and waterjet theory. The method is proved to be feasible through numerical simulation and analysis. Comparison between the calculated results and test data indicates that the numerical model and results are creditable. The calculation and analysis show that the decline quantity of head token of cavitation extent is respectively 1% , 2% and 20~ corresponding to cavitation limit lines Ⅰ,Ⅱ,Ⅲ And also the cavitation limit line is confirmed to be the equal cavitation specific speed line. Therefore, the method can be used to determine the cavitation limit lines for marine waterjet so as to help draw the integrated propulsion performance graph for guiding the safety operation of the waterjet.