以最小平方有限元素法探討雙橋墩流場變化

Study of the flow fields in a dual bridge-pier by least-squares finite element method

陳啟宏(Chi-Hom Chen)

指導教授 ： 鄧志浩

中原大學/工學院/土木工程研究所/碩士(2005年)

https://doi.org/10.6840/cycu200500054

摘要

以數值模擬方法研究流體經過雙橋墩流場變化。此方法使用最小平方有限元素法求解淺水波方程式。從模擬結果得知，接近橋墩時水深會壅起而過橋墩後方水深會下陷。當雙橋墩間距增加時，其干涉現象會由大逐漸變小。當兩橋墩間距超過4倍的直徑時，干涉現象可以忽視的。對於縱向排列的雙橋墩，干涉現象會較小，而其水深的分布也會類似單一橋墩現象。兩橋墩之間的水深隨著兩橋墩間距的增加水深會降低。本文研究，水深分布可有效地模擬和可能壅起的水體預測。希望結果能為水利工程學界被廣泛設計應用。

關鍵字

雙橋墩 ； 最小平方有限元素法 ； 淺水波方程式

並列摘要

A numerical simulation of the flow pass dual piers of a bridge has been presented in this study. The least-squares finite element method is employed for solving the governing shallow water equations. From the simulation results, it can be concluded that the water depth is accumulated proximal to the pier and drops immediately after the pier. The effect of the interference caused by the dual piers is strong and become weaker as the distance between the piers is increased. When the space between two piers is more than four times of the diameter of the pier, the effect of the interference is negligible. For the case of dual piers formed in a line along the flow direction, the effect of interference is small and the formation of the water depth is very similar to the distribution of a single pier. The water depth between two piers is lowered as the distance between piers increasing. In this study, the water depth distribution can be effectively simulated and the possible accumulation of water body is calculated. It is hoped that the results can
be used for the design purpose for the hydraulic engineering.

並列關鍵字

dual piers of a bridge ； least-squares finite element method ； shallow water equations

參考文獻

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