Chimera RANS/Laplace simulation of free surface flows induced by 2D ship sway, heave, and roll motions

A hybrid numerical method for the prediction of wave-body interactions including both viscous and nonlinear wave effects is presented. In this method, a chimera domain decomposition approach which combines a Laplace solver for nonlinear free surface waves and a Reynolds-Averaged Navier-Stokes (RANS) method is used. The Laplace solver provides the fully nonlinear waves away from the body. The PANS method in the near field resolves the boundary layers, the wake flows, and the nonlinear waves around the body boundary. The kinematic and dynamics free-surface boundary conditions are satisfied on the exact free surface in both the PANS and potential flow solution domains. The viscous-inviscid interaction is captured through a direct matching of the velocity and pressure fields in an overlapped PANS and potential flow computational domain. Calculations have been performed for a two-dimensional ship hull in prescribed sway, heave, or roll motions to demonstrate the capability of the chimera Laplace method and interactive RANS/Laplace coupling approach for time-domain simulation of nonlinear free surface waves around oscillating bodies. The numerical solutions successfully captured many important features of the transient flow induced by oscillating bodies including both the viscous and nonlinear wave effects.