Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/16290
標題: 具消波艙室開孔防波堤之波流場模擬
Numerical simulation of wave of perforated breakwater with a wave-absorbing chamber
作者: 王柏棟
Wang, Po-Tung
關鍵字: breakwater;防波堤;perforated-wall;wave-absorbing chamber;開孔胸牆;消波艙室
出版社: 土木工程學系所
引用: 1. 郭金棟 (1993) “新型防波堤之開發”,兩岸港口及海岸開發研討會,97-105 2. 謝世楞、李炎保、吳永強、谷漢斌 (2006) “圆弧面防波堤波浪力初步研究”,海洋工程,Vol. 24, No.1, 14-18. 3. Chen, X., Li, Y., Teng, B. (2006) “Numerical and simplified methods for the calculation of the total horizontal wave force on a perforated caisson with a top cover.” Coastal Engineering, Vol. 54, Issue 1, January 2007, Pages 67-75 4. Goda, Y., Suzuki, Y. (1976) “Estimation of incident and reflected waves in random wave experiments.” Proc. 15th Coastal Engineering Conference, Hawaii. pp. 828–845. 5. Goda, Y. (1985) “Random Seas and Design of Maritime Structures,” University of Tokyo Press, Tokyo, Japan. 6. Hirt, C.W., Nichols, B.D. (1981) “Volume of fluid method for the dynamics of free boundaries.” Journal of Computational Physics 39, 201– 225. 7. Jarlan, G.E. (1961) “A perforated vertical wall breakwater.” Dock & Harbour Authority 41 (486), 394-398. 8. Lemos, C.M. (1992) “A simple numerical technique for turbulent flow with free surface.” International Journal for Numerical Methods in Fluids 15, 127– 146. 9. Li, Y.C., Dong, G.H., Liu, H.J., Sun, D.P. (2003) “The reflection of oblique incident waves by breakwaters with double-layered perforated wall.” Coastal Engineering, Vol. 50, 47-60. 10. Liu, Y., Li, Y., Teng, B., Jiang, J., Ma, B. (2008) “Total horizontal and vertical forces of irregular waves on partially perforated caisson breakwaters.” Coastal Engineering, Vol. 55, 537-552 11. Mansard, E.P.D., Funke, E.R. (1980) “The measurement of incident and reflected spectra using a least square method.” Proc. of 15th Coastal Engineering Conference 1, 154-172. 12. Marks, W. and Jarlan G. E. (1968) “Experimental studies on a fixed perforated breakwater,” Proc. of 11th Conf. on Coastal Engineering chapter 71, pp. 1121~1140. 13. Sekiguchi, S.I., Miyabe, S., Yamamoto, Y., Miwa, T. (2002) “Development of a sloping-slit caisson breakwater.” Coastal Engineering Journal, Vol. 44, No. 3, 203 - 215. 14. Suh, K.D., Park, W.S. (1995) “Wave reflection from perforated-wall caisson breakwaters.” Coastal Engineering, Vol. 26,177–193. 15. Suh, K.D., Park, W.S., Park, J.K. (2006) “Wave reflection from partially perforated-wallcaisson breakwater,” Proc. Ocean Engineering, Vol. 33, 264–280. 16. Tanimoto and Yoshimoto (1982) K. Tanimoto and Y. Yoshimoto, “Theoretical and experiment study of reflection coefficient for wave dissipating caisson with a permeable front wall.” Report of Port and Harbour Research Institute 21 3 (1982), pp. 43–77 17. Takahashi, S. (1999) “Failure of composite breakwaters in Japan,” Proc. Lect. Port Harbar Res Inst. 18. Williams, A.N., Mansour, A.E.M., Lee, H.S. (2000) “Simplified analytical solutions for wave interaction with absorbing-type caisson breakwaters.” Ocean Engineering 27, 1231–1248. 19. Yakhot, V., and Orszag, S. A. (1986) “Renormalization group analysis of turbulence.” Journal of Scientific Computing 1, pp. 3–51. 20. Yakhot, V., and Smith, L.M. (1992) “The renormalization group, the ɛ-expansion and derivation of turbulence models.” Journal of Scientific Computing 7, pp. 35–61.
摘要: 
It is well known that a perforated-wall caisson breakwater not only reduces the wave reflection but also reduced the wave forces when comparing to a traditional caisson breakwater. During the past several decades, hydraulic model tests and mathematical models were performed for predicting the wave reflection of a perforated-wall. In this thesis, the numerical simulation was presented to investigate the characteristics of wave and turbulent energy dissipation of the caisson breakwater with wave chamber. The present perforated wall of the wave chamber consists of sloping-slit in the upper part and vertical-slit in the lower part.
The three-dimensional RANS with RNG turbulent model was applied for the numerical simulation that was implemented in the CFD code, Flow-3D. The numerical results of wave profiles and pressure variations first were in very good comparison with the experimental data. The wave reflection from the breakwater was analyzed for varied relative widths of the wave chamber and two kinds of porosity of the perforated wall. The results showed that the wave reflection decreased to a minimum value as the relative width of the wave chamber (B/L, L is the wavelength) is about 0.15. For the porosity λ= 25% of the wall, it was found that its reduction of wave reflection as well as the wave pressure was better than that of λ= 37.5%. As comparing to the traditional caisson breakwater without wave chamber, the maximum wave pressure could be reduced about 30% for the simulated cases. The numerical simulations show that the reduction of the wave reflection and the wave pressure were induced by the obvious turbulent energy dissipation as wave across the perforated-wall.

根據以往對防波堤之研究中可發現,其開孔胸牆對於防波堤有降低反射率、降低波壓力等效果。因此本研究針對具消波艙室防波堤進行研究,並利用Flow-3D此套軟體以流體運動方程式及紊流傳輸方程式中的RNG理論模擬其受波浪做用下之波流場探討、紊流能量消散效果、以及與傳統直立堤之各項效能比較。並且與具消波艙室防波堤實驗研究之結果相比較,而研究結果發現其模擬與實驗結果之趨勢相當吻合,且所得之波壓與波形亦相差無幾,由此證實其模擬之準確度。
文中首先探討具消波艙室防波堤之消波艙室相對寬度(B/L)比,並發現B/L為0.15時,其在降低反射率方面之效能最佳。而後針對開孔前壁之不同開孔率(λ)進行初步模擬,其結果發現λ=25%時,具消波艙室防波堤在降低反射率與波壓力之效能最佳,並且在各不同波浪條件下進行λ=25及37.5 %之比較結果亦是如此。在波流場與受力情形模擬方面,具消波艙室防波堤之斜面設計不但有助於堤體之安定性,且由於斜面開孔與下方直立面開孔之因素,造成其流速增加使得波流場紊亂,也因此具消波艙室防波堤之開孔處產生許多紊流能量之消散。
文中更將具消波艙室防波堤與傳統直立堤進行效能比較,而結果顯示具消波艙室防波堤在降低反射率、消減波能等皆明顯優於傳統直立堤,其中在降低堤面波壓力部分更可達到30%。
URI: http://hdl.handle.net/11455/16290
其他識別: U0005-2308201011104600
Appears in Collections:土木工程學系所

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