Qualification Criteria for the Verification of Numerical Waves – Part 1: Potential-Based Numerical Wave Tank (PNWT)

There is an increasing trend towards using numerical wave simulations for the design of offshore structures, especially for the stochastic prediction of nonlinear wave loads like those related to air-gap and wave impact. Unlike experimental facilities, where the complex nonlinear physics of wave propagation is simply enforced by the laws of nature, numerical wave tanks (NWTs) rely on assumptions and simplifications to solve the propagation equations in a reasonable amount of time. It is therefore important to verify the quality of the waves generated by NWTs in terms of realistic physical properties. As part of the effort to develop reliable numerical wave modeling practices in the framework of the “Reproducible Offshore CFD JIP”, qualification criteria are formulated for the wave solutions generated from either potential-flow based or CFD-based codes. The criteria have been developed based on experiences from physical wave tank tests and theoretical/numerical studies. They are being evaluated using results from several numerical models and available benchmark data. This paper presents the proposed qualification criteria and on-going evaluation efforts by comparing results from different codes.