Session: 08-01-03 Ship Design and Surface Wave Effects I

Paper Number: 126680

126680 - An Improved Interface Coupling Computational Fluid Dynamics With Potential Theory-Based Wave Descriptions 

This study employs the Steady Surface Gravity Wave (SSGW) theory and the periodical High Order Spectrum (HOS) method to define the wave environment. Unlike traditional streamfunction wave theories, SSGW theory has the advantage of being valid across all water depths. This method allows for the simulation of waves with steepness beyond what is achievable with 5th-order Stokes wave theory, and it also enables simulations in shallow water using the same theory.

A novel technique has been developed to reduce the cost of generating wave kinematics in CFD simulations. The key innovation in this technique is the use of bi-cubic interpolation to calculate velocity from the velocity potential, resulting in significant reductions in data volume and numerical costs. A similar technique is applied to link HOS solution wtih CFD simulation. 

The commercial CFD software STAR-CCM+ is used in this study. It is based on the Finite Volume Method with a segregated flow solver, using the Volume Of Fluid (VOF) model Multiphase model and offering different motion modeling capabilities.
The primary objective of this paper is to verify CFD wave simulations for later simulations of added resistance for the Sintef Ocean Bulk Carrier (SOBC-1) in head and following seas.

Verification studies employ regular waves, beginning with the validation of the Steady Surface Gravity Wave (SSGW) interface in comparison to the inbuilt Fenton's Stokes 5th order wave theory and the 5th order Cnoidal wave theory. This assessment is conducted in both standing and moving frames within CFD. Additionally, regular waves defined by the High Order Spectrum (HOS) are coupled with CFD. Both interfaces demonstrate high efficiency in terms of computational cost and a substantial reduction in the required data volume at the HOS interface.

Presenting Author: Csaba Pakozdi SINTEF Ocean

Presenting Author Biography: 2000 TU Berlin Dipl.Ing. Naval Architect
2000 - 2002 TU Berlin Researcher
2003-2008 NTNU, Trondheim PhD.
2007 - SINTEF Ocean former MARINTEK

Authors:

Csaba Pakozdi SINTEF Ocean
Martin Gutsch SINTEF Ocean
Joseph Sajan Esgian AS
Sebastien Fouques SINTEF Ocean