碩士 / 國立中興大學 / 土木工程學系所 / 99 / It is well known that a perforated-wall caisson breakwater reduces not only the wave reflection but also the wave forces. In this paper, the numerical simulation was presented to investigate the characteristics of waves on the caisson breakwater with trapezoidal wave-chambers which consists of two layers of slit wall. The three-dimensional RANS with RNG turbulent model was applied for the numerical simulation that was implemented with a CFD code, FLOW-3D.
The numerical results of wave profiles and pressure variations were first verified with the experimental data. The results of reflection coefficient with varied width of wave-chamber was compared with the previous experimental results as well. The wave reflection, the wave force, the turbulent energy dissipation and the different porosities of perforated wall were analyzed. As the wave passes through the perforated wall, the particle velocity increased and the vortex formed. When the wave passes the upper sloping-slit, the downward flow is generated. Turbulent dissipation usually occurs near the perforated wall which induces a greater energy loss it. The numerical simulations show the obvious reduction of the wave reflection and the wave force by the wave-chambers. The results indicated that the wave reflection from the wave-chamber and the wave force on the breakwater is minimal when B/L is about 0.15 where L is the wavelength and B is the width of wave chamber. Even for B/L = 0.2-0.5, the wave reflection and the wave force may be reduced in a great extent.
| Identifer | oai:union.ndltd.org:TW/099NCHU5015090 |
| Date | January 2011 |
| Creators | Hung-Yi Cheng, 程弘義 |
| Contributors | Ching-Piao Tsai, 蔡清標 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 67 |
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