关键词: 喷水推进, 轴流, 进口流道, 脉动压力, 模型试验

Abstract: A model test has been conducted for the fluctuating pressure of an axial-flow waterjet in a cavitation tunnel in order to study the effect of cavitation on the fluctuating pressure on the duct of the waterjet. A special test unit was built on the cavitation tunnel to make the experiment as close as possible to the actual operation condition of the waterjet. The test section of the cavitation tunnel was used to simulate the flow under the ship bottom and the inlet duct of the waterjet, and a bypass test device for the waterjet was then built above the test section. The tests under different flow rates and cavitation numbers were performed to measure the fluctuating pressure on the inner wall of the impeller section of a waterjet. The distribution of the fluctuating pressure along the chord length and circumferential direction of the impeller blade tip, and the cavitation effect are examined by optimizing the location of the measuring points. The experimental results show that along the chord length of the impeller blade tip, the effect of cavitation on the fluctuating pressure is mainly concentrated in the 0 ~ 50% chord length region. And the maximum fluctuating pressure along the circumferential direction occurs in the low velocity region caused by the inlet duct and impeller shaft, and the effect of cavitation on the circumferential fluctuating pressure is also concentrated in this region.

Key words: waterjet propulsion, axial flow, inlet duct, fluctuating pressure, model test