Application of Rigid Lid Boundary Condition for Three Dimensional Flow Analysis beneath Floating Structure

doi:2012.26.5.55

J. Ocean Eng. Technol. > Volume 26(5); 2012 > Article

J. Ocean Eng. Technol. 2012;26(5):55-62.
DOI: https://doi.org/10.5574/KSOE.2012.26.5.055

Hong Nam-Seeg

Department of Civil Engineering Donga University

부유체하부의 3차원 흐름해석을 위한 Rigid lid 경계조건의 적용

홍남식

동아대학교 토목공학과

Keywords: Rigid lid

핵심용어: 경계조건, ${sigma}$좌표계, 부유체, 압축계수, 국부압력, 자유수면

Abstract

In this paper, the rigid lid boundary condition is applied to simulate the influence of floating structures such as ships or pontoons, and the pressure term in both the momentum equations and continuity equation are modified. The pressure of a floating structure under the free surface is dependent on the draft of the structure, generally called a ship. If the free surface is covered by a floating structure, the free surface cannot move freely. The water level should be fixed, using a rigid lid boundary condition. This boundary condition is implemented by reducing the storage area of the grid cell with a factor between zero and one. The numerical model developed by Hong (2009) is verified through a comparison with experimental results, and the influence of the reduction factor is investigated using the verified numerical model.