New analytical solutions to water wave diffraction by vertical truncated cylinders

• Published in: International journal of naval architecture and ocean engineering 2019, 11(2), , pp.952-969
• Main Authors: Li, Ai-jun, Liu, Yong
• Format: Article
• Language: English
• Subjects: Cube-root singularity; Multi-term galerkin method; Truncated cylinders; Wave diffraction; Wave forces; 조선공학
• ISSN: 2092-6782; 2092-6790
• DOI: 10.1016/j.ijnaoe.2019.04.006

This study develops new analytical solutions to water wave diffraction by vertical truncated cylinders in the context of linear potential theory. Three typical truncated surface-piercing cylinders, a submerged bottom-standing cylinder and a submerged floating cylinder are examined. The analytical solutions utilize the multi-term Galerkin method, which is able to model the cube-root singularity of fluid velocity near the edges of the truncated cylinders by expanding the fluid velocity into a set of basis function involving the Gegenbauer polynomials. The convergence of the present analytical solution is rapid, and a few truncated numbers in the series of the basis function can yield results of six-figure accuracy for wave forces and moments. The present solutions are in good agreement with those by a higher-order BEM (boundary element method) model. Comparisons between present results and experimental results in literature and results by Froude-Krylov theory are conducted. The variation of wave forces and moments with different parameters are presented. This study not only gives a new analytical approach to wave diffraction by truncated cylinders but also provides a reliable benchmark for numerical investigations of wave diffraction by structures.