Investigation on motion characteristics of an Anti-pitching Generating WEC (AGWEC) considering the viscous effect

Abstract

Anti-pitching Generating Wave Energy Converter (AGWEC) uses the relative pitch motion between floating bodies to push the hydraulic energy storage PTO movement, which reduces the relative pitch between floating bodies while generating power. In this paper, based on the CFD method and the potential flow theory with viscosity modification, the motion characteristics of AGWEC in waves are studied. The viscous dissipation term is introduced into the boundary condition of potential flow, and the viscous modified potential flow theory method is established. The Eigenfunction Expansion Matching (EEM) method and Impulse Response Function (IRF) method are used to analyze the motion response of the device in frequency domain and time domain respectively. At the same time, compared with the results of CFD method based on Star-CCM+, the universality of the two methods is proved, and the motion characteristics of the AGWEC based on (non)linear PTO system and the variation law with the relevant parameters are obtained under different floating body axial spacing and wave frequency.