Comparative study on ship motions in waves based on two time domain boundary element methods

• Published in: Engineering analysis with boundary elements Vol. 111; pp. 9 - 21
• Main Authors: Mei, Tian-Long, Zhang, Teng, Candries, Maxim, Lataire, Evert, Zou, Zao-Jian
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2020
• Subjects: Rankine higher-order boundary element method; Ship hydrodynamics; Ship motion in waves; Time domain; Transient free surface Green's function; Ship hydrodynamics; Time domain; Transient free surface Green's function; Rankine higher-order boundary element method; Ship motion in waves
• DOI: 10.1016/j.enganabound.2019.10.013
• ISSN: 0955-7997

This paper presents a comparative study on the motions of a ship advancing in waves using two different three-dimensional time domain boundary element methods: a Transient Free surface Green's Function (TFGF) method and a Rankine Higher Order Boundary Element Method (HOBEM). Three models based on the HOBEM are also considered to identify the dominant factors affecting the accuracy of solutions: (i) the N–K model using Neumann–Kelvin (N–K) linearization, (ii) the N–K+DB model using the N–K linearization for the free surface boundary conditions and the double-body (DB) m-terms in the body boundary condition, (iii) the Rankine HOBEM based on DB linearization. The Wigley I and the Series 60 (CB = =0.7) are taken as study objects. The comparisons show that the Rankine HOBEM based on DB linearization is generally more accurate than the Rankine HOBEM with other two models and the TFGF method. The hydrodynamic coefficients are mainly affected by the m-terms, especially at low frequencies; while the influences of different linearizations of the free surface boundary conditions are negligible. Both the m-terms and the leading terms of steady velocity potential reserved in the free surface boundary conditions are important for motion responses, while the influence of the former is stronger than the latter.