Numerical investigation of the influence of vortex generator on propeller cavitation and hull pressure fluctuation by DDES

In this study, the delayed detached eddy simulation (DDES) is coupled with a homogenous cavitation model to simulate the cavitating turbulent flow around a propeller behind a full body ship with special emphasis on the influence of the vortex generator (VG) on the propeller cavitation and the hull pressure fluctuation. The small calculation uncertainty as evaluated by the DDES verification and validation (V&V) method indicates that the present simulation can accurately reproduce the propeller performance and cavitation, and the predicted hull pressure fluctuation is in a fairly good agreement with the available experimental data. The mechanism is explored through the current numerical results how the VG affects the local velocity distribution, along with the influences of the VG on the propeller cavitation and the hull pressure fluctuation. It is shown that the streamwise vortex is induced by the VG near the hull boundary layer. The very low velocity region in the hull wake is reduced due to the effect of the streamwise vortex. Besides, the propeller cavitation develops more mildly and the hull pressure fluctuation decreases due to the influence of the VG.