A novel method for deriving the diffraction transfer matrix and its application to multi-body interactions in water waves. (15th January 2015)

• Record Type: Journal Article
• Authors: McNatt, J. Cameron; Venugopal, Vengatesan; Forehand, David
• Is Part Of: Ocean engineering. Volume 94(2015)
• Page Start: 173
• Page End: 185
• Publication Date: 2015-01-15
• Subjects: Multiple scattering -- Wave energy converter -- Wave farm -- Wave field -- Diffraction transfer matrix; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2014.11.029
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: A matrix method was developed byKagemoto and Yue (1986) to compute interactions between multiple three-dimensional bodies subjected to linear water waves. The approach leads to a significant reduction in computational time versus the direct method, in which the boundary value problem is solved for all bodies simultaneously. An essential component of the theory is the so-called diffraction transfer matrix, a linear operator defined for each unique geometry. However, the diffraction transfer matrix is not a standard product of a linear wave computation, for one, because it is based around an unusual representation of incident waves, that is, as partial cylindrical waves. In this paper, a new method is presented to compute the diffraction transfer matrix from plane incident waves, which enables one to derive it from standard wave-body software or experiments. Additionally, a new linear operator – the force transfer matrix, is presented, which can also be determined by usual means. Herein, the interaction theory calculation is verified against direct method results from the linear wave-body software, WAMIT, and then applied to compute absorbed power and wave field effects on a medium-sized array in spectral seas and on a large farm of 101 wave energy converters in regular waves. Abstract : Highlights: We apply multiple scattering theory to compute floating body array interactions. We developed a new method to find the diffraction transfer matrix. We introduce a new hydrodynamic operator, the force transfer matrix. Our method can be performed with data from standard software or experiments. We compute interactions for a wave energy farm of 101 devices (808 total DOF).