Numerical investigation and experimental observation of unsteady tip leakage cavitating flow for the axial waterjet pump

In this paper, experimental observation and numerical calculation are applied to investigate the vortex-cavitation interactionin the blade tip region. Calculated performances have good agreement with experimental results. The evolution of TLVC is analysed byHigh-speed photography (HSP) at the selected cavitation condition. Liutex method was adopted to identify the tip leakage vortex (TLV)core centre. According to the radial location of the TLV core centre and the development of TLVC, the flow along the blade can bedivided into three regimes: stable cavitation, unstable cavitation and non-cavitation flow. Tip leakage flow (TLF) and main flow haveeffects on the TLV intensity and trajectory. Finally, different terms of vorticity transport equation were used to analyse the contributionof cavitation to the production and reallocation of vorticity in a rotating frame. It shows that circumferential dilatation and axial vortexstretching terms mainly contribute to vorticity production and its relocation.