環流傳輸係數對彎道汙染質側向傳輸之影響分析

Effect of Circulatory Mixing Coefficient on Lateral Contaminant Transport in Channel Bend

許芳綺(Fang-Chi Hsu)

指導教授 ： 楊錦釧 ； 謝德勇

國立交通大學/工學院/土木工程系所/碩士(2013年)

https://doi.org/10.6842/NCTU.2013.00788

摘要

本研究分別採用擬似三維與水深平均二維模式進行彎道汙染傳輸模擬，探討環流傳輸效應對側向傳輸的影響，其中擬似三維模式可利用解得的垂向流場與濃度場自動反應環流傳輸效應，水深平均二維模式則採用在梯度定理假設下所推導而得的Fischer等(1979)環流傳輸經驗公式來反應環流傳輸效應。本研究採用不符合梯度定理假設的Almquist and Holley(1985)連續彎汙染傳輸實驗案例進行模擬，分析不同環流傳輸效應模擬結果的差異性。

關鍵字

汙染傳輸 ； 擬似三維 ； 水深平均二維 ； 環流傳輸效應

並列摘要

A quasi-3D model and a two-dimensional depth-averaged model are adapted in this study to analyze the circulatory-transport effect for the contaminant transport in open-channel bends. The quasi-3D model can provide the vertical velocity and contaminant profiles, so that the circulatory-transport effect can be computed automatically from theknown velocity defect. The two-dimensional depth- averaged model adopts Fischer et al. (1979) circulatory-transport formula, which was derived based on the gradient transport assumption, to empirically reflect the circulatory-transport effect. The contaminant transport test in a meandering channel reported by Almquist and Holley (1985), which does not conform to the gradient transport assumption, is adopted herein to evaluate the difference between the models.

並列關鍵字

Contaminant Transport ； semi-3D ； two-dimensional depth-averaged ； circulatory transport effect

參考文獻

鍾浩榮(2012)，河道三維高含砂水流沉滓運移模式發展與應用，國立交通大學土木工程研究所博士論文。

Blumberg, A.F., and Mellor, G.L. (1983), Diagnostic and prognostic numerical circulation studies of the South Atlantic Bight. Journal of Geophysics Research, 88(C8):4579-4592

Elder, J.W.(1959), The Dispersion of Marked Fluid in Turbulent Shear Flow. Journal of Fluid Mechanics, Vol.5,Part 4, May 1959.

Falconer, R.A. (1980), Numerical modeling of tidal circulation in harbors. J Waterway Port Coast Ocean Div; 106: 31-48.

Fischer，et al.(1979),Mixing in Inland and Coastal Waters,Academic Press,New York.