Flow characteristics of submerged cavitating jet impinging on convex target based on organ pipe nozzle: experiment and numerical investigation

• Identify ring-shaped erosion mechanisms based on velocity and vapor fraction. • Reveal curvature-induced vortex trapping and non-uniform bubble collapse. • Extract dominant POD modes to characterize convex-surface effects on cavitation dynamics. • Capture transient cavitating-jet evolution on a convex surface via high-speed imaging. For cleaning applications involving curved structures in marine engineering, this study investigates the erosion characteristics of submerged cavitating jets impinging on the convex target and the associated influencing factors. The cavitation cloud erosion on the convex surface undergoes a three-stage evolution: contact ( T 1 ), spreading along the wall ( T 2 ), and collapse ( T 3 ). Vortex trapping during T 2 plays a key role in the formation of erosion rings. The stress-blended eddy simulation ( SBES ) accurately reproduces the generation, spreading, and collapse of cavitation clouds observed in experiments. Curvature-induced non-uniform pressure and velocity fields, together with the resulting near-wall vortex structures, lead to non-uniform erosion-ring distributions. Proper orthogonal decomposition ( POD ) analysis shows that convex confinement significantly restructures the coherent features of the cavitation cloud. The dominant modal frequencies increase, and energy becomes concentrated in Modes 1 and 2. Convex geometry also strongly affects the spatiotemporal switching of vortical structures in the cavitating jet. This study improves the understanding of cavitation erosion mechanisms under curved-surface conditions and provides guidance for the design and parameter optimization of cavitating jet systems in marine engineering.