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研究生： 李漢明
Lei, Hon-Meng
論文名稱： 二維垂直振動槽顆粒混合物因密度效應導致分層現象之實驗研究
Experimental studies on density-induced particle segregation in a dry granular mixture in 2D vertical vibration
指導教授： 方中
Fang, Chung
學位類別： 碩士
Master
系所名稱： 工學院 - 土木工程學系
Department of Civil Engineering
論文出版年： 2011
畢業學年度： 99
語文別： 中文
論文頁數： 143
中文關鍵詞： 顆粒混合物 、垂直振動 、密度效應 、臨界無因次加速度
外文關鍵詞： granular mixture, density-induced, vertical vibration, critical dimensionless acceleration
相關次數： 點閱：153  下載：4 
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    • 本研究在進行準二維垂直振動槽顆粒混合物因密度效應導致分層現象之實驗研究，使用相等體積但不同密度之圓球顆粒，觀察垂直振動下顆粒之運動行為。一顆追蹤顆粒放置底層中間位置，其他放置與其密度不同之環境顆粒，在5層堆積厚度，密度差異較大時，所需要的臨界無因次加速度較小，追蹤顆粒沿著振動槽中央位置上升；10層堆積厚度時，與5層堆積厚度之結果接近，只是所需之臨界無因次加速度較大；由於15層堆積厚的實驗數據不足，導致結果不明確。另外，振幅是決定顆粒分層的重要因子，在10層和15層堆積厚度時，振幅必須為3 mm 才可發生顆粒分層；還有振幅提升有助降低臨界無因次加速度，以及配合一定堆積厚度，產生更為明顯之對流滾動，使追蹤顆粒在厚層堆積時仍然出現分層現象。

    The present study is concerned with density-induced particle segregation in a binary dry granular mixture, which is composed of a single spherical trace particle and a large amount of identical environmental particles under vertical vibration, in which the trace and environmental particles assume different densities. Experimental results show that as the density ratio is far away from 1 with 5 layers, it is found that there is smaller dimensionless acceleration to separate each other, and the 10 layers’ dimensionless acceleration is more than the 5 layers’. According to the insufficient experimental data, the result of 15 layers is not clear. Amplitude is an important factor of particle segregation. As the amplitude increases, the time span for the trace particle rising on the top of the mixture becomes shorter, and also the critical dimensionless acceleration decreases. Also, the segregation will occur only if the amplitude is equal to 3 mm. Finally, the particle thicknesses increase to 10 or 15 layers with the amplitude increases, the convection rolls occur and become unique criterion to have the density-induced particle segregation.

    摘要................................................. i Abstract............................................ ii 誌謝............................................... iii 目錄................................................ iv 圖目錄.............................................. vi 表目錄.............................................. xi 符號說明........................................... xii 第一章 顆粒物質導論.................................. 1 1.1 顆粒物質......................................... 1 1.2 分層現象與文獻回顧............................... 1 1.3 研究目的與動機.................................. 11 1.4 論文架構........................................ 11 第二章 實驗設計與資料擷取分析....................... 12 2.1 簡介............................................ 12 2.2 實驗設備........................................ 12 2.3 儀器介紹........................................ 15 2.4 實驗步驟........................................ 18 2.5 資料擷取方法.................................... 27 2.6 實驗進行次數與每次所需時間...................... 27 第三章 實驗結果與數據整理........................... 29 3.1 實驗說明........................................ 29 3.1.1 振動強度設定.................................. 29 3.1.2 時間設定...................................... 33 3.1.3 速度與加速度之計算............................ 33 3.1.4 顆粒分層之界定................................ 34 3.1.5 實驗驗證...................................... 34 3.2 實驗結果........................................ 35 第四章 結果討論.................................... 136 4.1 堆積厚度為5層之結果............................ 136 4.2 堆積厚度為10層之結果........................... 137 4.3 堆積厚度為15層之結果........................... 138 4.4 其它........................................... 139 第五章 結論與未來展望.............................. 140 5.1 結論........................................... 140 5.2 未來展望....................................... 141 參考文獻........................................... 142 簡歷............................................... 143

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