喷水推进泵临界空化工况空化流态试验

在舰艇空间尺寸的限制下，提高推进器的综合性能是舰船设计的关键。空化是喷水推进泵的主要噪声源和重要设计参数。为降低舰艇的噪声，提高喷水推进泵的空化性能，十分有必要研究空化流动结构演变规律及其对喷水推进泵性能的影响。以某型喷水推进泵为研究对象，采用高速摄像技术开展了喷水推进泵临界空化工况空化流动结构演变规律试验研究。在空化发生和发展过程中，喷水推进泵空化流动结构包括片状空化、云状空化、叶顶间隙空化、叶顶泄漏涡空化和垂直空化涡。试验捕捉了空化演变的物理过程，分析了各空化流动结构对喷水推进泵性能下降的影响。结合数值模拟和前人研究，阐述了空化流动结构形成机理及其对喷水推进泵性能的影响。研究结果为喷水推进泵内的空化现象提供了新的认识，也为空化性能预测方法的研究给予了借鉴和指导。 

Experiment on cavitation flow in critical cavitation condition of water-jet propulsion pump

Under the limiation of ship space, it is the key of ship design to improve the comprehensive performance of propeller. Cavitation is the main noise source of water-jet propulsion pump, so it is an important design parameter of water-jet propulsion pump. In order to reduce the noise of the ship and improve the cavitation performance of the water-jet propulsion pump, it is necessary to study the evolution law of the cavitation flow structure and its influence on the pump performance. In this paper, the evolution mechanism of cavitation flow structures in the critical cavitation conditions of water-jet propulsion pump is captured by high-speed photography. The cavitation flow structures of the water-jet propulsion pump during the occurrence and development of cavitation include sheet cavitation, cloud cavitation, tip leakage cavitation, tip vortex cavitation and vertical cavitation vortex. The experiment captures the physical process of cavitation evolution and the effect of each cavitation flow structure on pump performance degradation is analyzed. Combined with simulation and previous research, this paper further expounds the formation mechanism of cavitation flow structure and its influence on the pump performance.The research results not only provide new understanding of the cavitation phenomenon in the water-jet propulsion pump, but also provide reference and guiding significance for the study of cavitation performance prediction methods.