推进泵快速启动水力特性及流场演变研究

In order to improve the velocity of torpedoes, the transient calculation model of a torpedo launch⁃ ing propulsion pump during rapid start-up process was established based on the Reynolds average N-S equa⁃ tion and SST k-ω turbulence model in present paper. The hydraulic characteristics and the flow field evolu⁃ tion of the propulsion pump under three start-up time conditions were studied by numerical method. The re⁃ sults show that the flow rate and the thrust continue to increase with time. The head, the axial force, the axial moment and the power increase at first and then decrease. The efficiency firstly increases and then remains stable. The maximum values of the head, the axial force, the axial moment and the power appear at the end of acceleration, and the maximum values decrease with the increase of start-up time. At the beginning of start⁃ up, there are serious inflow impact, flow separation and vortex structure in the impeller area, and the flow field tends to be stable gradually with time. Start-up time has a significant effect on the flow field evolution of the propulsion pump. The smaller the start-up time is, the faster the flow field reaches stable state. In order to ensure that the propulsion pump has no cavity and the internal flow field runs to stable state in a relatively short time during star-up process, it is recommended to start propulsion pump by 0.2 seconds start-up time.