Complex flow characteristics of marine centrifugal pump with balance holes in full flow field based on rotation–curvature correction

Marine pumps are critical components of ship power systems, whose operational stability and noise characteristics are strongly influenced by unsteady internal flow. Under complex operating conditions, flow unsteadiness induces hydraulic excitation and pressure pulsations, leading to increased vibration, noise, and reduced service reliability. This study numerically simulated the full flow field of a marine pump with balancing holes based on the rotational curvature modified shear-stress transport with scale-adaptive simulation to investigate the hydraulic excitation and flow features under different operating conditions. Meanwhile, combined with the entropy production theory and vorticity transport equation, the unsteady flow mechanism inside the pump was evaluated. The results show that the pressure pulsations at the volute tongue have a primary frequency of 1fBPF with secondary frequencies of 2fBPF and 3fBPF. The rotor–stator interface between the leading edge of the blade and the leakage chamber, the volute tongue, and the diffusion section has a strong intensity of pressure pulsations, and the entropy production rate is high in these zones. Moreover, the vortex stretching and the Coriolis force play a major role in the generation and development of flow passage vortices in the impeller, while the vortex viscous dissipation has a minor effect. These findings provide guidance for the optimal design and vibration-noise reduction of marine pumps.