A Study on the Numerical Radiation Condition in the Steady Wave Problem

J. Ocean Eng. Technol. 1998;12(2):97-110.

Lee, Gwang-Ho;Jeon, Ho-Hwan;Seong, Chang-Gyeong;

Busan National University;Busan National University;Busan National University;

정상파 문제의 방사조건에 관한 연구

이광호;전호환;성창경;

부산대학교;부산대학교;부산대학교;

Keywords: Steady Wave, Radiation Condition, Dispersion Error, Damping Error, Finite Difference, Panel Shift, Higher Order Boundary Element

핵심용어: 정상파, 방사조건, 분산오차, 감쇠 오차, 유한차분, 패널이동, 고차경계요소

Abstract

The numerical damping and dispersion error characteristics associated with difference schemes and a panel shift method used for the calculation of steady free surface flows by a panel method are an analysed in this paper. First, 12 finite difference operators used for the double model flow by Letcher are applied to a two dimensional cylinder with the Kelvin free surface condition and the numerical errors with these schemes are compared with those by the panel shift method. Then, 3-D waves due to a submerged source are calculated by the difference schemes, the panel shift method and also by a higher order boundary element method(HOBEM). Finally, the waves and wave resistance for Wigley's hull are calculated with these three schemes. It is shown that the panel shift method is free of numerical damping and dispersion error and performs better than the difference schemes. However, it can be concluded that the HOBEM also free of the numerical damping and dispersion error is the most stable, accurate and efficient.