Calculating buoy response for a wave energy converter-A comparison of two computational methods and experimental results

- Added mass, radiation damping and exciting force are calculated using a COMSOL model.
- The hydrodynamic parameters are compared to parameters from WAMIT.
- The equations of motion for a WEC are solved to find buoy movement and line force.
- Force and motion are compared to experimental offshore data, showing good agreement.

When designing a wave power plant, reliable and fast simulation tools are required. Computational fluid dynamics (CFD) software provides high accuracy but with a very high computational cost, and in operational, moderate sea states, linear potential flow theories may be sufficient to model the hydrodynamics. In this paper, a model is built in COMSOL Multiphysics to solve for the hydrodynamic parameters of a point-absorbing wave energy device. The results are compared with a linear model where the hydrodynamical parameters are computed using WAMIT, and to experimental results from the Lysekil research site. The agreement with experimental data is good for both numerical models.