Interactive RANS/Laplace Method for Nonlinear Free Surface Flows

Abstract

A hybrid numerical method for the prediction of free surface flows including both nonlinear wave and viscous effects is presented. In this method, a zonal approach that combines a potential flow method for fully nonlinear free surface waves and a Reynolds-averaged Navier-Stokes (RANS) method for turbulent incompressible flow is used. The potential flow equation is solved in the far field to provide the nonlinear waves generated by the body motion. The RANS method is used in the near field to resolve the turbulent boundary layer and wake flows around the body. Extensive results are presented for a submerged hydrofoil with and without the presence of free surface waves. The coupled RANS and potential flow method successfully resolves the body boundary layer, the viscous wake, and the nonlinear free surface waves. The results clearly demonstrate the feasibility of the coupling approach and therefore enables the use of a rather small RANS solution domain for efficient and accurate resolution of free surface flows including both the viscous and nonlinear wave effects.