大顆粒在垂直振動床中局部浮力分離機制的研究;Investigation of Intruder Local Buoyancy Force Segregation Mechanism in a Vertically Vibrated Granular Bed

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题名:	大顆粒在垂直振動床中局部浮力分離機制的研究;Investigation of Intruder Local Buoyancy Force Segregation Mechanism in a Vertically Vibrated Granular Bed
作者:	費單尼;FIRDANI, TUTUKO
贡献者:	能源工程研究所
关键词:	立式振動顆粒床;浮力;顆粒分離;大顆粒;Vertical Vibrated Granular Bed;Buoyancy Force;Granular Segregation;Intruder
日期:	2021-01-12
上传时间:	2021-03-18 17:19:25 (UTC+8)
出版者:	國立中央大學
摘要:	流體之後處理第二好的材料是粒狀材料。如今，無論是工業界還是自然界，顆粒分離都是粉體和顆粒加工中最具挑戰性的問題。顆粒分離非常複雜，並且有許多不同的分離驅動機制。過去幾年中，一些研究人員已經完成了許多隔離機制.Huerta等人在2005年進行的一項研究發現，入侵者的隔離過程和入侵者的活動尚未完全被理解。入侵盤的偏析機制是由垂直振動引起的。通過垂直注入高頻正弦振動，可以對Pseudo2D顆粒床進行流化處理。通過將磁盤入侵者浸入顆粒床中進行的顆粒分離研究。入侵盤從底床的分離過程是由浮力推動的。通過圖像處理技術定義入侵者盤的運動，並通過高精度力傳感器測量浮力。入侵者的密度越輕，其從床底到其自由表面的加速度就越大，而較重的入侵者的加速度就越小。一旦入侵者和顆粒床之間的相對密度超過1，入侵者便開始下沉。入侵者盤的上升/下沉取決於密度，並且受到垂直振動顆粒床中發生的浮力現象的影響。入侵者的相對密度越輕，浮力越大，反之亦然。與普通液體相比，垂直振動中的浮力效應是完全不同的現象。在隔離過程中，入侵者以不同的力和速度上升。影響入侵者動力的局部浮力以非恆定速度運動。入侵盤在垂直振動下受局部浮力作用控制。由於沿床高度的不均勻顆粒溫度，在我們的系統中發生了局部浮力效應。而且，由於垂直振動的顆粒床的各向異性系統，顆粒溫度的這種梯度。;The second most manipulated material after the fluid is granular material. Nowadays, granular segregation is the most challenging issues in powder and granular processing both industry and nature. Granular segregation is extremely complex and there are many different segregation driven mechanism. There were many segregation mechanism that have been done by some researchers in previous years. A study by Huerta et al in 2005 found that intruder segregation process and motion of the intruder were not completely understood. The segregation mechanism of the intruder disk was induced by vertical vibration. A Pseudo-2D granular bed is fluidized by injecting high frequency sinusoidal vibration vertically. The studied of the granular segregation conducted via immersion of the disk intruder into granular bed. The segregation process of intruder disk from the bottomed bed was driven by buoyancy-like force. The motion of intruder disk was defined via image processing technique and the buoyancy force was measured via high precision force sensor. The lighter density of intruder rose with larger acceleration from the bed bottom to the free surface of the bed rather than the heavier one rose with fewer acceleration. Once the relative density between the intruder and granular bed was exceed 1, the intruder started to sink. The rising/sinking of the intruder disk dependent on density and it was affected by the buoyancy force phenomena that occurred in the vertically vibrated granular bed. The buoyancy force was larger for the lighter relative density of the intruder and vice versa. The buoyancy effect in vertical vibration was completely different phenomena compared with ordinary liquid. During the segregation process intruder rise both with different force and velocity. The local buoyant force affecting the dynamic of intruder move with non-constant velocity. The intruder disk in the vertical vibration governed by local buoyancy effect. The local-buoyancy effect was occurred in our system because of unequally granular temperature along the bed height. Moreover, this gradient of the granular temperature due to anisotropic system of the vertically vibrated granular bed.
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