SPIV measurements and URANS simulations on the inlet velocity distribution for a waterjet-propelled ship with stabiliser fins

This study focused on the inlet velocity profile of a waterjet-propelled ship model during bare hull and waterjet-operating conditions. The ship model used in the analysis incorporates four mounted waterjets and two stabiliser fins. A combined experimental and numerical investigation was conducted to explore the complex viscous flow fields with high turbulence around the hull. A vehicle-mounted underwater Stereo Particle Image Velocimetry (SPIV) system was employed to measure the inlet velocity profile, and numerical simulations of the unsteady multiphase flow were also conducted considering the free-surface effects. The results indicate that the unsteady Reynolds-Averaged Navier-Stokes (URANS) simulations correctly reflected the pitch and heave trends and accurately captured the characteristics of the flow field. The inclusion of stabiliser fins induced shedding vortices thereby affecting the inlet velocity distribution as these vortices are convected downstream. The comparison of the experimental and numerical analyses of the inlet velocity distributions demonstrated that the experimental scatter varies with speed and strong pulsations exist near the interface between the mainstream and turbulent boundary layer. Very good correspondence was observed for the energy/momentum velocity coefficients, which verified the quality of the combined research quantitatively.