A fast approach coupling Boundary Element Method and plane wave approximation for wave interaction analysis in sparse arrays of wave energy converters

•A fast approach for wave interaction analysis in sparse arrays of WEC is proposed.•Interaction among the bodies due to scattered waves is taken into account by PWA.•Approach is useful when interspacing is atleast 5 times the dimensions of the body.•Impact of wave interactions on energy production by large array of WECs is analyzed.

A computational approach is developed to investigate wave interaction effects in sparse arrays of floating bodies (such as wave energy converters) based on linear potential theory. In particular, the wave diffraction and radiation problems in a multiple body array are solved in reasonable time and accuracy. In contrast to previous approaches that have considered all bodies in the array as a single module, the present approach treats each body in the array as an isolated body. The interactions resulting from the scattered wave field among the bodies are then taken into account via plane wave approximation in an iterative manner. The boundary value problem corresponding to an isolated body is solved by the Boundary Element Method (BEM). The approach is useful for wave periods in the range 4–15 s, provided that the bodies are separated by at least five times the characteristic dimension of a body. The main advantage of the approach is that the computational time and memory requirements are significantly less than that of conventional BEM. In this paper, first, the numerical results for hydrodynamic coefficients computed by the proposed approach are validated against conventional BEM. Next, the wave interaction effects on power production are investigated in arrays of 50 wave energy converters.