Near Trapped Modes in Long Array of Truncated Circular Cylinders

Wave Exciting Force Maximization of Truncated Cylinders in a Linear Array

“…The first-order (linear) boundary value problem is formulated and solved by utilizing the matched eigenfunction expansion technique, combined with the "direct" solution methodology for the numerical implementation. This semi-analytical approach was developed and described in [10,25]. For making this study self-contained, we briefly present the main aspects of the approach taken in [10,25].…”

“…This semi-analytical approach was developed and described in [10,25]. For making this study self-contained, we briefly present the main aspects of the approach taken in [10,25].…”

“…For realizing such an optimum layout configuration, the multiple wave scattering problem of the mutually interacting truncated cylinders of the array should be solved in a robust and accurate way. This problem has been extensively and effectively tackled in the past by many researchers, who developed and applied relevant analytical and numerical methods aiming at: (a) the direct evaluation of the exciting forces applied on the cylinders for a specific predefined array (e.g., [1][2][3][4]), or (b) the assessment of the effect of different layout configurations on the exciting forces (e.g., [5]) or, finally, (c) the investigation of the mode trapping phenomena (e.g., [6]) and their effect on the cylinders' exciting forces (e.g., [7][8][9][10]). It should be noted that in all of the above studies the cylinders were placed at either symmetrical locations relative to the direction of the incident waves or at equally spaced positions within the examined configuration.…”

“…It should be noted that in all of the above studies the cylinders were placed at either symmetrical locations relative to the direction of the incident waves or at equally spaced positions within the examined configuration. Moreover, in [8] it was emphasized that an array of closely spaced cylinders can result in a large increase of both the free-surface elevation and the wave exciting forces, while for the case of a linear array, Chatjigeorgiou et al [10] demonstrated that the change of the center-to-center spacing between the cylinders of the array has a significant effect on the induced surge and heave exciting forces.…”

“…The developed ONP consists of two distinctive numerical components, appropriately coupled in an integrated computational environment. The first one corresponds to a hydrodynamic model (HM), which solves the diffraction problem of the examined multi-body arrangement in the frequency domain in an accurate and computationally efficient manner, by utilizing the matched eigenfunction expansion technique and the "direct" solution methodology for the numerical implementation [10,25]. Accordingly, it calculates the linear heave exciting forces of the cylinders.…”