本研究為了瞭解水流通過彎道的流場特性和不同密度的流體通過彎道的流場狀況，藉由繪製三維模型以數值方法模擬Rozovskii（1961）所進行的180°彎道定床模型試驗。本模擬主要採用六面體網格所組成，總網格數約11萬個，利用泛用計算流體力學程式FLUENT軟體的Realizable k-ε Model搭配VOF模組來進行模擬，並與實驗値進行比較。由模擬結果與實驗的比較發現，泛用計算流體力學軟體FLUENT可以成功模擬水流通過彎道的二次流和水面超高的狀況，進一步將實驗流體視為一均勻流體，藉由改變材料密度和黏滯係數來模擬含砂水流通過彎道的流場狀況，發現密度較大的液體水面超高有增加的趨勢，而最大水面超高的位置則有延後的現象。在不同密度流體的模擬上，因為密度差距過小使得水面線、流速等流況非常接近。

This research focuses on the characteristics of the flow in bend with different density. It uses a numerical approach with a three-dimension model to simulate the 180∘curve channel in bed which Rozovskii had done the experiment on 1961.
The simulation model uses the hexahedron grids in composition which the total grid number is approximately 110 thousands. A Realizable k- epsilon Model and a VOF Model in FLUENT is used to run the simulation, and discusses with the results. The experimental fluid is regarded as an uniform fluid, the material density and viscosity coefficient are regarded as the parameters in the simulation of the flow field about the water containing the granulated substance to pass the curve channel.
By the comparison of the simulation and the experiment results, the FLUENT may succeed in the simulation that the current of water can pass the curve with the secondary flow and the super-elevation. But the simulation in different density fluid is not good. Because the disparity of density is too small to let the water surface and the velocity extremely close.

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