Seakeeping Validation and Verification Using Decomposition Model Based on Embedded Free Surface Method

Validation and verification of a KCS model in head seas is presented in this paper for five wave conditions. Validation is performed by comparing added resistance, heave and pitch motions with experimental data. Numerical model is verified via grid refinement studies, assessing grid uncertainty for each test case. Periodic uncertainty by means of moving window FFT is introduced and assessed. The decomposition model is based on SWENSE (Spectral Wave Explicit Navier–Stokes Equations) method and implicit relaxation zones. Jump conditions at the interface are used to obtain interface–corrected interpolation schemes for density and pressure, embedding the free surface into two single–phase equations for water and air. The method fully resolves issues with parasitic air velocities and ensures one–cell–sharp jump of dynamic pressure and density across the free surface. Implicitly redistanced Level Set equation is used for interface capturing, while the k − ω SST model is used for turbulence. The method is implemented in the Naval Hydro pack based on foam–extend, a fork of the open source software OpenFOAM.