Unmanned underwater vehicles (UUVs) have become a research focus in underwater robotics due to their extensive applications in marine scientific research, environmental protection, and engineering operations. The seawater hydraulic axial piston pump (SHAPP), as the core component of the UUV buoyancy adjustment system, is critical to its performance. However, in certain specialized operating conditions, SHAPPs are required to possess self-priming capability to actively draw in water from external environments or high-pressure tanks. To fulfill this requirement, this study proposed a novel boost impeller-seawater hydraulic axial piston pump (BI-SHAPP) that integrates an impeller at the pump inlet for priming and boost. The computational fluid dynamics model accounting for the four key friction pairs within the piston pump was established. Simulation results indicated that under negative inlet pressure, the BI-SHAPP demonstrates superior boost capability and effectively mitigates cavitation compared to a conventional SHAPP. Furthermore, experimental verification on a two pressure/two systems test confirmed that the BI-SHAPP maintains a higher and more stable outlet flow under negative suction pressure, with the integrated impeller significantly reducing system pressure ripples. This study presents an innovative centrifugal boost impeller-integrated seawater hydraulic pump solution to fulfill the self-priming demand of seawater pumps in UUV applications.
Yin et al. (2026) studied this question.