In the context of the European VIRTUE program dealing with the improvement of CFD models for naval applications, Principia, Bassin d'Essais des Carènes and Ecole Centrale de Nantes work on the sea-keeping work-package of the project. It concerns the development and the validation of CFD codes for the simulation of non-linear hydrodynamic effects such as ship roll damping due to viscosity and wave radiation. The paper shows sea-keeping applications based on comparisons between numerical simulations performed with the CFD code EOLE of Principia and measurements carried out at the Bassin d'Essais des Carènes.
The sea-keeping numerical simulations are performed out with the CFD code EOLE developed by Principia. URANS equations are solved using multi-blocks curvilinear meshes. Turbulence is included with a k-ε model and the free surface is considered using a VOF implicit model. Harmonic roll motion is imposed to the mesh (fixed to the ship) in the absolute frame to simulate forced oscillations tests, with or without forward speed of the ship. Forced oscillations tests have been carried out in the B600 basin at Val de Rueil, on a hull model test at 1/24 scale. A specific test arrangement is used for the tests. The 3D motion generator from ECN (hexapod), fixed on the towing carriage, allows forced roll motions. Several tests have been performed in calm water considering a large range of periods, roll amplitudes and forward speeds.
The Hamburg test case model (HTC), coming from HSVA Hamburg, is considered. The scale of the model is 1/24 and hydrostatics of HTC are presented in table 1. Pictures of the model are shown on Fig. 1. The main objective of the test campaign is to provide experimental data to validate numerical tools on the specific issue of viscous roll damping simulation for ship in forced roll motion.