Investigation of Global Regular Wave Loading on a Damaged Ship using CFD

Ocean going ships undergo significant loading at sea and are designed to survive severe sea states in an intact condition. However, little consideration is given to the structural integrity of vessels which are damaged. This can be attributed to the limited knowledge of ship responses in their damaged state. An assessment on the viability of the commercial CFD package STAR-CCM+ as a tool for assessing damaged ships has been undertaken by Lougheed (2012) and Goatly (2013).

A model was set up emulating experimental damaged hull sections oscillating in a tank with RANS and LES turbulence models. Hydrodynamic coefficients from the simulations were compared with experimental and theoretical work quantitatively and qualitatively. To investigate the validity of an enclosed hull form with aerostatic pressure, the model used an enclosed air reservoir.

Though there is little difference between the hydrodynamic coefficients from LES and RANS simulations using STAR-CCM+, LES is able to capture the vorticity inherent in the fluid flow giving insight into the physical nature of the flow. STAR-CCM+ was able to accurately predict the added mass of an enclosed hull section with aerostatic stiffness, however, the ability of the software to predict damping remains inconclusive.

Thomas Goatly
Speaker Company: 
Ministry of Defence