Investigation of Cavitation Flow Field and Flow Loss in Shaftless Water-Jet Propulsion Pump Under Different Acceleration Conditions

This study discusses the effect of different acceleration modes on the shaftless water-jet propulsion pump’s operational performance. Following the usage of Renault-time-mean Navier–Stokes (N-S) equations combined with an application of the shear stress transport (SST) k-ω turbulence mode and reinforced by an experimental test platform, the research explores internal energy loss shaftless water-jet propulsion pump flow behavior under exponential and linear acceleration processes. The results indicate that, compared to linear acceleration, the cavity volume within the impeller is marginally greater during the initial phase of exponential acceleration; however, this trend reverses in the subsequent stages; The amplitude of fluctuations in the pressure pulsation coefficient at both the mid-span and root regions of the blade, along with the amplitude corresponding to the primary frequency of the pressure pulsation, are comparatively reduced. Turbulent entropy production at the rim constitutes a significant component of energy loss; however, the total entropy production exceeds this contribution.