Abstract: Cavitation will affect the normal and stable operation of the pump. In order to explore a strategy that can effectively inhibit the development of cavitation in an axial flow pump, a method of arranging rectangular flow obstacles on the back of the axial flow pump vanes is proposed. Taking an axial-flow pump with a specific revolution of 700 as the research object, the influence of obstacles on the external characteristics and cavitation performance of the axial-flow pump was analyzed by using the full-channel unsteady numerical simulation. The results show that, under design conditions, the improved model with obstacle arrangement consistently reduces the cavity volume across all stages, especially when the cavity develops to the position of the obstacle, achieving a reduction in the cavity volume by 72.5%. The arrangement of obstacles increases the pressure at the back outlet of the blade, restricts the expansion of the low-pressure area to the outlet, reduces the adverse pressure gradient, blocks the deflection at the hub side, clears the flow line of cavitation development, optimizes the flow field structure, and inhibits the development of cavitation, consequently increasing the fracture head by 10.19%.

Key words: axial flow pump, flow direction, obstacle, cavitation suppression, unsteady