-351- 第 32 屆海洋工程研討會論文集 國立臺灣海洋大學 2010 年 11 月 Proceeding of the 32 nd Ocean Engineering Conference in Taiwan National Taiwan Ocean University, November 2010 Model Development on Simulating a Float Obstacle Tso-Ren Wu 1 Mei-Hui Chuang 2 Chih-Jung Huang 3 Chung-Yue Wang 4 Chia-Ren Chu 4 Meng-Zhi Chen 5 1 Assistant Professor, Graduate Institute of Hydrological and Oceanic Sciences, National Central University 2 Research Assistant, Graduate Institute of Hydrological and Oceanic Sciences, National Central University 3 Graduate Student, Department of Civil Engineering, National Central University 4 Professor, Department of Civil Engineering, National Central University 5 Graduate Student, Department of Civil Engineering, National Central University ABSTRACT In this paper, we developed a two-way coupled moving solid model to simulate a floating box oscillating in a water tank. The numerical model is developed based on the FVM (finite volume method) to solve the LES (Large-Eddy Simulation) model. The free-surface is described by the VOF (Volume of Fluid) method with the PLIC (Piecewise Linear Interface Calculation) scheme. The simulation is executed on a fixed mesh. The velocity at the solid boundary is specified as the boundary face velocity of the fluid cells. The partial-cell treatment is used to represent the effective cell volume. This newly developed model is able to simulate incompressible high-speed fluid motion with stable pressure field. A benchmark problem of the floating box is presented in this paper and used to validate the numerical model. Keywords: Moving solid algorithm (MSA); Discrete Element Method (DEM); Volume of Fluid (VOF); Float obstacle 浮體模擬之模式發展 吳祚任 莊美惠 黃致榮 王仲宇 朱佳仁 陳孟志 摘要 本研究發展雙向流顧耦合模式，以移動邊界法與離散元素法計算水中浮運動，數值模式 以有限積法為基準，求解 LES（大渦模擬）模式。以 VOF 流積法配合 PLIC（分段線性 介面法）描述自由液面，並於固定網格系統執行。透過指定流網格面速度以達到給定固邊 界速度的效果，並採用部分網格法呈現網格的有效積。此一創新發展的模式能夠在壓力穩定 的情況下，有效模擬不可壓縮流況中速的流運動。本文提出浮基準問題，用以驗證數值 模式。 關鍵詞：移動固法、離散元素法、流積法、浮 Ⅰ . Intriduction The numerical simulation of water waves interacting with a float obstacle is important for many sciences and engineering applications, such as ship maneuvering, and wave energy. However, to analyze unsteady flows with free surfaces poses a great challenge to numerical simulations, because both of the free-surface boundary and the moving solid boundary are presented in the fluid system, and both elements are parts of the solutions.