The aim of the present study is to provide a rigorous analysis of the water wave modelling capabilities of the advanced multipurpose CFD code Fluidity. This code has been developed at Imperial College London over a large number of years and benefits from an open source GNU license. In contrast to similar studies adopting closed-source in-house or commercial solutions, the results presented herein may be verified by any computer literate reader. The investigation focuses on the simulation of gravity water waves; their detailed understanding being fundamental to the design of many offshore (marine) solutions, including the emerging fields of wave energy conversion and floating offshore wind applications. Both small amplitude (linear hydrodynamics) and finite amplitude (nonlinear hydrodynamics) regular waves are simulated in a 2D Numerical Wave Tank (NWT). First, and assessment of the NWT's capabilities in accurately modelling wave propagation and wave energy conservation of linear waves is undertaken. Subsequently, the simulated wave field is directly compared with results obtained from linear wavemaker theory. For the purpose of the nonlinear wave investigation, two wave generation techniques are adopted, and comparisons with a high-order potential flow theory are made. The overall agreement between the simulation results and theory was found to be very good.

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A rigorous analysis of the water wave modeling capabilities of the advanced multipurpose CFD code Fluidity is presented. The study focused on the simulation of gravity water waves; their detailed understanding being fundamental to the design of many offshore (marine) solutions, including the emerging fields of wave energy conversion and floating offshore wind applications. Both small amplitude (linear hydrodynamics) and finite amplitude (nonlinear hydrodynamics) regular waves were simulated in a two-dimensional Numerical Wave Tank. To study the nonlinear wave, two wave generation techniques were adopted, and comparisons with a high-order potential flow theory were made. The wave group and the wave phase velocities showed excellent agreement with analytical solutions. The generation of nonlinear water waves was implemented using two different methodologies, i.e., a depth-constant piston-mode velocity distribution and a fifth-order Stokes velocity distribution. In both cases, a qualitative analysis indicated very good agreement with the expected fluid behavior. This is an abstract of a paper presented at the Proceedings of the Twenty-Second International Offshore and Polar Engineering Conference (Rhodes, Greece 6/17-22/2012).@en