Estimation of the hydrodynamic derivatives by RaNS simulation of planar motion mechanism test

Abstract

Maneuverability prediction in design phase is one of the key requirements in ship design to ensure safety and economy of the ship. Generally, researchers and designers rely on towing tank tests to determine ship maneuverability properties and force derivatives. This paper discusses the possibility of applying Computational Fluid Dynamics (CFD) as an alternate to towing tank test for predicting ship maneuverability properties along with hydrodynamic derivatives using a RaNS based solver. The paper includes Planar Motion Mechanism (PMM) test results produced using CFD and compares the results with two sets of test data. It also discusses the derivation of force derivatives from the simulated PMM results and compares them with test ones. The results show good agreement in static drift and pure sway cases. As for pure yaw case, some discrepancy is observed, which may be attributed to the insufficiency of test data. The paper concludes that, CFD shows high promise as an efficient and economical alternative to existing towing tank tests in determining ship hydrodynamic coefficients.