Numerical investigation on the flow control effect of serrated trailing edge on pump-jet propulsor under oblique flow conditions

This study employs numerical simulations to investigate the effects of a serrated trailing edge (TE) on the hydrodynamic performance and flow field characteristics of a pump-jet propulsor (PJP) under oblique flow conditions. The results reveal that the flow control effect of serrations exhibits strong angle dependence, with the optimal performance observed at an oblique angle of 10°. At this condition, the rotor thrust loss is minimal (0.58%), while wake pressure pulsations are significantly suppressed, leading to improved flow stability. The mechanism analysis indicates that the serrated TE fragments large-scale vortices into smaller, more dispersed structures, thereby weakening coherent vortex shedding and improving wake stability. Compared with a straight TE, serrations demonstrate stronger resistance to flow asymmetry and interference at medium to large inflow angles, effectively reducing vortex intensity and pressure pulsations. These findings confirm the potential of the serrated TE as a passive flow control and noise-reduction strategy, providing valuable data for the optimized design of a PJP in complex operating conditions.