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This paper is devoted to the assessment of ship maneuvering simulation using different propeller models with the focus on a simplified propeller model that represents the action of the propeller by body force and uses propeller performance curve to determine propeller loading during ship maneuvering. Simulations are also performed with an actual propeller approach with which the propeller rotation is simulated directly with the Reynolds averaged Navier-Stokes equation (RANSE) solver. Both time accurate simulations using sliding grid and rotating frame approximations have been performed for comparison. The zigzag and turning circle maneuvers in calm water have been simulated for two different ship models, namely the ONR tumblehome (ONRT) test case and the KRISO (Korea Research Institute of Ship and Ocean) Container Ship (KCS) test case. Predicted ship motion is compared with measurement data to assess the accuracy of the numerical prediction using RANSE computations with different propeller models.

ABSTRACTThe study describes a synthesis of a numerical and experimental work performed during the European research project EFFORT (European Full-scale FlOw Research and Technology) aiming at studying scale effects for hulls of high geometrical complexity by numerical and experimental means. During this project, the CFD group of Fluid Mechanics Laboratory (UMR6598) has performed a complete study of scale and appendage effects on an hopperdredger “Uilenspiegel”. These computations are discussed and compared with available local wake measurements obtained within EFFORT.

An interface capturing method based on a numerically revisited procedure for velocity and pressure coupling is worked out. The new treatment of density discontinuity is formulated in the framework of the finite volume methodology for arbitrary unstructured grids. A simple analytical pressure-like model case is presented to illustrate the accuracy of the numerical implementation of the treatment of discontinuous variables. Then, the method is implemented in a viscous flow solver and applied to free-surface flows, including the two-dimensional Rayleigh–Taylor instability problem and three-dimensional hydrodynamic flows for the prediction of ship waves around the Series 60 model ship with and without drift angles. These latter simulations show excellent agreement with the experimental results illustrated by comparisons of free-surface elevations and also velocity field. [Copyright &y& Elsevier]

Highlights: [•] The paper studies grid refinement for realistic free-surface hydrodynamic flows. [•] Good refinement criteria are a combination of free-surface and derivative-based ones. [•] Refinement criteria based on the pressure Hessian need to contain smoothing. [•] Ratio of two criteria is set independent of scaling, Froude or Reynolds number. [•] Fine meshes of good quality are generated entirely with automatic grid refinement. [ABSTRACT FROM AUTHOR]

Abstract: An adaptive grid refinement method is presented for hydrodynamic flow simulation. It is meant for application to a wide range of realistic flow problems, so generality and flexibility of the method are essential. Directional refinement is developed to be used with unstructured hexahedral meshes, tensor-based refinement allows the implementation of many different refinement criteria. Good grid quality is assured by creating buffers of refined cells around relevant flow features. Tests are performed with two refinement criteria, based on the free surface and the Hessian matrix of the solution respectively; these show great increases in efficiency with respect to non-refined grids. [Copyright &y& Elsevier]