顆粒氣體於非對稱容器之聚集與振盪

Clustering and oscillation of the granular gas in a non-symmetrical container

邱方志(Fang-Chih Chiu)

指導教授 ： 陳國慶

國立臺灣大學/工學院/應用力學研究所/碩士(2009年)

https://doi.org/10.6342/NTU.2009.03024

摘要

顆粒氣體於容器中受到垂直振動後，會有不同顆粒狀態出現，如：均勻分佈狀態、單格聚集狀態、顆粒鐘現象、不穩定區、兩格聚集狀態等等。而本實驗針對顆粒氣體於非對稱容器下，其顆粒現象加以探討。為了更清楚描述非對稱容器，本實驗定義了α、β兩個無因次參數，分別代表兩格容器及三格容器的非對稱值，為容器的最大間格底面寬度和最小間格底面寬度的比值。若當α、β值為1時，則代表容器為對稱容器。α、β值大於1時，則代表容器為非對稱容器。

比較顆粒氣體於對稱容器及非對稱容器下，其顆粒聚集、顆粒鐘現象、均勻分佈狀態等等差別，及顆粒聚集的習性等。在兩格非對稱系統中，發現了顆粒聚集會傾向於小區發生。在推廣至三格非對稱系統後，發現顆粒容易在兩側端的較小區聚集，不容易在中格區域聚集。且本實驗中發現隨著更換容器的α、β值後，在Γ-N圖中的聚集線、Γ-α圖及Γ-β圖中的100%穩定線、均勻分佈線、小區聚集線、在二元二格系統內的顆粒鐘現象、發生聚集時各區間的顆粒溫度差異等，皆會隨著容器的非對稱性α、β而使加速度值上升或下降、顆粒鐘現象增加、左右兩區的溫差變大等等。

關鍵字

顆粒氣體 ； 非對稱 ； 顆粒聚集 ； 顆粒振盪

並列摘要

When granular gas receives vertical vibrations in a symmetrical container, it will predent a few interesting phenomena, such as homogeneous state, unstable-gas state, one-clustering state, oscillation state and two-clustering state. On the present thesis, we experemently study the clustering and oscillation of the granular gas in non-symmetrical containers. In order to describe the vessel's non-symmetry, we defined two dimension -less parameters, α and β to represent the two-compatmentalized non-symmetry and the three-compatmentalized non-symmetry, respectively. When the value of parameters α or β is 1, it represents the container is symmetric.
We also compare the granular clusteris in a symmetrical and non-symmetrical container for the homogeneous state, unstable-gas state, one-clustering state, oscillation state and two-clustering state and so on. In the two-compatmentalized non-symmetry, the granular gas clustering prefers the small region. As to the non-symmetric three- compatmentalized container, the granular gas clustering prefers left or right region and not clustering in middle region. The results also finds that as changing the parameters α and β, the clustering line, completely clustering line, homogeneous clustering line, oscillation and granular temperature in each container are altered accordingly.

並列關鍵字

granular gas ； non-symmetry ； granular clustering ； granular oscillation

參考文獻

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