Integrated Numerical Modelling System for Extreme Wave Events at the Wave Hub Site

This paper examines an extreme wave event which occurred during a storm at the Wave Hub site in 2012. The extreme wave of 9.57 m height was identified from a time series of the heave data collected by an Oceanor Seawatch Mini II Buoy deployed at the site. An energy density spectrum was derived from this time series and then used to drive a physical model, which represents the extreme wave at 1:20 scale in Plymouth University’s new COAST Lab. The NewWave technique was used to define the input to the physical model. The experiment is reproduced in a numerical wave tank using the fully nonlinear CFD library OpenFOAM® and the wave generation toolbox waves2Foam. Results are evaluated, and issues regarding the predictions of a numerical model that is driven by the NewWave input signal are discussed. This study sets the basis for further research in coupling field data, physical modelling and numerical modelling in a more efficient and balanced way. This will lead to the new approach of composite modelling that will be implemented in future work

Validation of a cfd-based numerical wave tank of the wavestar wec

CFD-based numerical wave tank (CNWT) models, are a useful tool for the analysis of wave energy converters (WECs). During the development of a CNWT, model validation is important, to prove the accuracy of the numerical solution. This paper presents a validation study of a CNWT model for the 1:10 scale Wavestar point-absorber device. The previous studies reported by Ransley et al. (2017) and Windt et al. (2018b) are extended in this paper, by including cases in which the power-take off (PTO) system is engaged. In this study, the PTO is represented as a simple linear damping term in the CNWT WEC model, providing a first approximation to the full PTO dynamics, to be included in the CNWT in future work. The numerical results, for surface elevation and device position, are shown to compare well with the experimental measurements