計算流力在潰壩波與結構物互制之研究

Internation of Dam-Break Waves with Structures by Computational Fluid Dynamics

羅德章(Der-Chang Lo) ； 吳姿潓(Zih-Huei Wu) ； 陳震武(Cheng-Wu Chen)

《海洋工程學刊》 12卷2期 (2012/12) Pp. 147-169

https://doi.org/10.6266/JCOE.2012.1202.02

摘要

本研究應用計算流體力學套裝軟體（FLOW-3D）模擬潰壩波通過結構物的互制作用，本文採用紊流模式的Navier-Stokes方程式，並應用流體體積法來處理自由液面的流動問題。為了驗證本模式，先模擬典型的潰壩問題，並與實驗室的數據比對，得到很精確的預測。再應用本模式模擬不同的案例有（a）潰壩波與不同長寬比的方型結構物互制作用，結構物的長寬比由0.25~5，（b）潰壩波與串排的兩方柱型結構物之作用，（c）潰壩波與不同直徑的圓柱作用，（d）潰壩波與串排的兩圓柱型結構物之作用，（e）不同初始水位的潰壩波與方柱型結構物的作用。模擬的案例用來驗證本模式的可行性，並從結果來探討潰壩波作用於結構物引發的流固耦合之效應、結構物隨時間受力的變化情形、速度分布的流場變化與自由液面變化。

關鍵字

潰壩波 ； 計算流體力學 ； 串連排列

並列摘要

The purpose of present study aims at the dam-break waves over the structures using a computational fluid dynamics (CFD) package (Flow-3D). The methodology is based on the Navier-Stokes equations through a Renormalization Group Model (RNG) model, and the free-surface is calculated through a volume of Fluid (VOF) technique. To demonstrate the model feasibility, firstly a typical dam-break problem is demonstrated by comparing the present results with experimental data, where we have achieved results with high accuracy. Furthermore, the present study subsequently gives reasonable results on problems including the (a) dam-break flow for rectangular cylinder with various aspect ratios (structure length / structure width) varying from 0.25 to 5; (b) dam-break flow past a pair of rectangular cylinders for the tandem arrangement; (c) dam-break flow for circular cylinder with various diameters; (d) dam-break flow past a pair of circular cylinders for the tandem arrangement; (e) interaction between a dam-break surge and a square cylinder with various elevations initially. The example is employed to demonstrate the feasibility and the results are described in detail such as the time-based variation of acting force on structure, velocity distribution, and elevation of free surface.

並列關鍵字

dam-break waves ； computational fluid dynamics (CFD) ； tandem arrangement