低汽蚀余量高速泵诱导轮研究

诱导轮是用来改善高速泵汽蚀性能的重要部件。为了研究诱导轮设计参数对高速泵汽蚀性能的影响,对一台卧式高速泵的诱导轮分别进行了3种方案的设计,并且对安装了每一种设计方案诱导轮的卧式高速泵都在试验室进行了相应的汽蚀试验,试验结果显示通过合理设计诱导轮参数可以显著提高高速泵的汽蚀性能。为了进一步研究诱导轮内部液体的流动状态,采用雷诺时均方法,对诱导轮内部的流场进行数值模拟,研究了诱导轮叶片工作面上相对速度分布及压力分布情况。依据数值模拟和试验结果,提出了对于本结构的高速泵诱导轮设计时诱导论的扬程系数应小于0.15,进口液流冲角要在合理范围内选取,不能取值过小。在合理的设计条件下,高速泵配备相等螺距诱导轮可以达到优良的汽蚀性能。

Study of inducers for low-NPSHr high-speed pumps

The inducer is an important part to improve cavitation performance of high-speed pump. In order to research the effect of the design parameters of the inducer on cavitation performance of high-speed pumps, three design schemes of inducer for a horizontal high-speed pump were made respectively, and then a corresponding cavitation experiment was performed in laboratory for the horizontal high-speed pump with each designed inducer. The experimental results shows that cavitation performance of the high-speed pump can be remarkably improved if the parameters of the inducer are reasonably designed. In order to research the liquid flow state in the inducer, the method of RANS was adopted to simulate internal flow field in the inducer numerically to determine the relative velocity distribution and pressure distribution on the working face of inducer. Results of experimental research and numerical calculations prove that the head coefficient of this kind of inducer should be less than 0.15 and fluid inlet angle of attack should be reasonably adjusted. The high-speed pump with equal pitch inducer and rational design can obtain excellent cavitation performance.