Numerical investigation of the influence of wave parameters on maneuvering hydrodynamic derivatives in regular head waves

Abstract

To evaluate the wave effect on the maneuvering hydrodynamic derivatives in the research of maneuverability in waves, the experimental and numerical studies on the Planar Motion Mechanism (PMM) tests in regular head waves for the standard ship model KVLCC2 are carried out. The simulations are performed by an up-to-date Unsteady Reynolds Averaged Navier-Stokes (URANS) solver. Overset mesh technique and Euler Overlay method are adopted. The simulation results are validated using the experimental data obtained from the PMM tests in towing tank of Shanghai Jiao Tong University. The comparison of the hydrodynamic derivatives in waves and calm water conditions reveals that the wave effect on Yr′ can be ignored except for the extremely steep wave condition. However, Nr′ is significantly changed by the wavelength and wave steepness. This finding shows that there is an error in the previous assumption that the hydrodynamic derivatives in waves are the same as those in calm water. In addition, a simple modification for the wave effect on high-order hydrodynamic derivatives is hard to be proposed due to the random changing tendency of these parameters. The instantaneous flow field information is also obtained and indicates that the influence of waves on the free surface contour and dynamic pressure is more significant than that of low-frequency maneuvering motions.