| DC 欄位 |
值 |
語言 |
| DC.contributor | 機械工程學系 | zh_TW |
| DC.creator | 李韋逸 | zh_TW |
| DC.creator | Wei-Yi Lee | en_US |
| dc.date.accessioned | 2023-11-28T07:39:07Z | |
| dc.date.available | 2023-11-28T07:39:07Z | |
| dc.date.issued | 2023 | |
| dc.identifier.uri | http://ir.lib.ncu.edu.tw:88/thesis/view_etd.asp?URN=109323043 | |
| dc.contributor.department | 機械工程學系 | zh_TW |
| DC.description | 國立中央大學 | zh_TW |
| DC.description | National Central University | en_US |
| dc.description.abstract | 本研究採用未解析法的計算流體力學與離散元素法雙向流耦合(Unresolved CFD-DEM)模擬顆粒體在水中崩塌的流動行為，並比較對應的物理實驗結果，探討流體網格尺寸、阻力模型、及虛擬質量力的影響，進一步分析顆粒體崩塌速度分布與出口處顆粒體積流率。研究結果顯示：(1)顆粒體在水中崩塌的速度分布隨著顆粒體深度增加而減少，水槽壁面處顆粒體呈現SSH (Sidewall Stabilized Heap)流態；(2)流體網格尺寸為顆粒粒徑3倍時，顆粒體流速模擬結果與實驗結果較吻合；(3)不考慮虛擬質量力模型，Gidaspow, Bezburuah & Ding與Di Felice阻力模型的預測結果與實驗結果較相近；(4)考慮虛擬質量力模型的預測結果與實驗結果較相近，且虛擬質量力對顆粒體速度的影響隨著顆粒體深度增加而減少；(5)水槽中心處顆粒體的平移速度大於壁面處顆粒體的平移速度，顆粒體垂直水槽方向的旋轉速度大於水平與重力方向的旋轉速度，表示顆粒體主要在水槽平面上轉動。 | zh_TW |
| dc.description.abstract | The purpose of study is to investigate the collapse behavior of granular columns in water by using unresolved couple CFD-DEM model, and this model is validated against corresponding physical experiments. The compared physical properties included analyze velocity profile and volume flow rate of granular flows at the outlet. The study investigates the effects of fluid cell size, drag force model, and virtual mass force model. Key findings are highlighted below : (1) The velocity of granular flows decreases as the depth of granular flows increases, exhibiting the SSH rheology；(2) As the fluid cell size is about three times the particle diameter, the simulation results shows very agreement with the experimental results；(3) If the virtual mass force model is not considered, the simulation results for the Gidaspow, Bezburuah & Ding and Di Felice drag models are consistent with the experimental results；(4) The numerical models with the virtual mass force model match the experimental results, and the influence of virtual mass forces on the granular flow decreases with increasing flow depth；(5) The translational velocities of granular flows at the center of the tank are greater than those at the sidewalls. The angular velocities of granular flows about the out-of-plane direction are greater than those about the horizon and vertical directions, indicating that granular flows primarily lie in the plane. | en_US |
| DC.subject | 水中顆粒體崩塌行為 | zh_TW |
| DC.subject | 流體網格尺寸 | zh_TW |
| DC.subject | 阻力模型 | zh_TW |
| DC.subject | 虛擬質量力 | zh_TW |
| DC.subject | Unresolved CFD-DEM | en_US |
| DC.subject | granular column collapse in water | en_US |
| DC.subject | fluid cell size | en_US |
| DC.subject | drag force | en_US |
| DC.subject | virtual mass force | en_US |
| DC.title | 以計算流體力學及離散元素法雙向耦合模擬水中顆粒體崩塌行為與內部性質：網格尺寸、阻力模型與虛擬質量力模型 的參數研究 | zh_TW |
| dc.language.iso | zh-TW | zh-TW |
| DC.type | 博碩士論文 | zh_TW |
| DC.type | thesis | en_US |
| DC.publisher | National Central University | en_US |