Comparison of Experimental Data of a Moored Multibody Wave Energy Device With a Hybrid CFD and BIEM Numerical Analysis Framework

Abstract

In the present paper, a hybrid Computational Fluid Dynamics (CFD) and Boundary Integral Element Method (BIEM) framework is developed in order to study the response of a moored Multibody wave Energy Device (MED) to a panchromatic sea state. The relevant results are the surge and heave responses of the MED. The Numerical Analysis Framework (NAF) includes two different models; the first model uses Navier-Stokes equations to describe the flow field and is solved with an in-house CFD code to quantify the viscous damping effect, while the second model uses boundary-integral equation method and is solved with the tool WAMIT\SIMO\RIFLEX. By studying the free decay tests with the Navier-Stokes based model, the uncoupled linear and quadratic damping coefficients of the MED in surge and heave directions are calculated. These coefficients are given as input to the WAMIT\SIMO\RIFLEX model and the responses of the MED to different wave conditions are determined. These responses are compared with the experimental data and very good agreement is obtained. The MED responses calculated by the presented NAF have been obtained in connection with a hydrodynamic modeling competition and selected as one of the numerical models, which well predict the blind experimental data that were unknown to the authors.