車-橋斷面耦合之CFD風力係數模擬

Computational Fluid Dynamics Simulation of Aerodynamic Coefficients on Bridge-Vehicle systems

賴冠廷(Kuan-Ting Lai)

指導教授 ： 張正興

淡江大學/工學院/土木工程學系碩士班/碩士(2013年)

https://doi.org/10.6846/TKU.2013.00639

摘要

相較於風洞試驗來得到試體斷面的風力係數之花費與動員人力，以計算流體力學（computational fluid dynamics, CFD）方式來模擬橋樑斷面周圍之風場特性更顯其經濟。這之中不只可模擬橋斷面周圍流場的壓力、速度的分佈情形，並可獲得橋斷面在不同風攻角下之風力係數，以為未來橋梁受風力作用的風力動態分析之用。

本文將以ANSYS之FLUENT軟體作為CFD計算風場網格的模擬基礎，針對矩形斷面、高屏溪橋斷面進行風力係數模擬，並與前人之風洞試驗進行分析比較。與此同時，對於數值模擬之紊流模型、模型外觀以及粗糙度在不同風攻角下對氣動力係數之影響，進行討論，並依此模式為基礎，就高屏溪橋斷面之車-橋系統的風力係數與周圍風場的探討。最後，根據車-橋耦合斷面之模擬結果將其可視化模擬，並觀察其車-橋間之風壓流場變化情形，以釐清一般風洞實驗看不到的現象。

根據本文之研究結果，將可提供對橋梁斷面之CFD模式建立及模擬方法，透過快速的數值模擬，以做為風洞試驗前風力係數之評估參考，並為接下來的CFD氣彈力模擬做好先期基礎工作。

關鍵字

CFD ； 風工程 ； 風力係數 ； 計算流體力學 ； 橋梁 ； FLUENT

並列摘要

Use Computational Fluid Dynamics (computational fluid dynamics, CFD) to simulate the wind field around bridge deck section and aerodynamic coefficients more economical than wind tunnel tests.CFD can simulate the pressure of the flow field around the bridge section and speed distribution. And CFD can get the bridge section of aerodynamic coefficients under different wind direction ,that future bridges subjected to the action of the wind in the wind dynamic analysis purposes.
This article will use ANSYS FLUENT software as the CFD computational simulation of the wind field grid foundation to simulate the aerodynamic coefficients for rectangle cross-section and the Kaoping bridge cross-section . Using the above results compared with the previous wind tunnel test to illustrate the numerical simulation of turbulent flow model, model appearance and roughness under different wind direction of aerodynamic coefficient. And use this result to simulate aerodynamic coefficient and flow field around the section for Bridge-Vehicle systems
Visualization according to the Vehicle-Bridge cross-section of the simulation results observed the change of wind pressure and flow field between cars and bridge, in order to observe the general wind tunnel experiments can't observed phenomenon.
We can use the results of this study provide the CFD simulation settings and simulation mode of the bridge deck section through rapid numerical simulation can be used as the assessment of aerodynamic coefficient before the wind tunnel tests and prepare CFD aeroelastic simulation basic.

並列關鍵字

Fluent ； CFD ； Wind engineering ； Bridge

參考文獻

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