Ship Roll Analysis Using CFD-Derived Roll Damping: Numerical and Experimental Study

This study investigates the roll decay of a fishing vessel by experiments and computational fluid dynamics (CFD) simulations. A fishing vessel roll decay is tested experimentally for different initial roll angles. The roll decay is also simulated numerically by CFD simulations and is validated against the experimental results. It shows that the roll damping could be obtained by CFD with high level of accuracy. The linear and nonlinear damping terms are extracted from the CFD roll decay results and are used in a potential-based solver. In this way we are using a hybrid solver that benefits the accuracy of the CFD results in terms of roll damping estimation and the fast computations of the potential-based solver at the same time. This hybrid method is used for reproducing the free roll decays at Fn=0 and also in analyzing some cases in waves. The experiments, CFD and the hybrid parts are described in detail. It is shown that the suggested method is capable of doing the simulations in a very short time with high level of accuracy. This strategy could be used for many seakeeping analyses.