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| DC 欄位 | 值 | 語言 |
|---|---|---|
| dc.contributor.advisor | 周逸儒(Yi-Ju Chou) | |
| dc.contributor.author | Ting-Yun Zhuang | en |
| dc.contributor.author | 莊婷筠 | zh_TW |
| dc.date.accessioned | 2021-06-08T01:46:53Z | - |
| dc.date.copyright | 2020-08-24 | |
| dc.date.issued | 2020 | |
| dc.date.submitted | 2020-08-17 | |
| dc.identifier.citation | [1] Bosse, T., et al. (2005). 'Numerical simulation of finite Reynolds number suspension drops settling under gravity.' Physics of Fluids 17(3): 037101. [2] Chandrasekhar, S. (1981). Hydrodynamic and Hydromagnetic Stability, Dover Publications. [3] Chou, Y.-J., et al. (2019). 'Instabilities of particle-laden layers in the stably stratified environment.' Physics of Fluids 31(12): 124101. [4] Chou, Y.-J., et al. (2015). 'An Euler–Lagrange model for simulating fine particle suspension in liquid flows.' Journal of Computational Physics 299: 955-973. [5] Chou, Y.-J., et al. (2020). 'Formation of drops and rings in double-diffusive sedimentation.' Journal of Fluid Mechanics 884: A35. [6] Green, T. and J. W. Schettle (1986). 'Vortex rings associated with strong double‐diffusive fingering.' The Physics of Fluids 29(7): 2109-2112. [7] Houk, D. and T. Green (1973). 'Descent rates of suspension fingers.' Deep Sea Research and Oceanographic Abstracts 20(8): 757-761. [8] Israelachvili, J. N. (2011). 'Intermolecular and surface forces.' Intermolecular and surface forces. [9] Khelifa, A. and P. S. Hill (2006). 'Models for effective density and settling velocity of flocs.' Journal of Hydraulic Research 44(3): 390-401. [10] Kranenburg, C. (1994). 'The Fractal Structure of Cohesive Sediment Aggregates.' Estuarine, Coastal and Shelf Science 39(5): 451-460. [11] Lagaly, G. (1978). 'H. van Olphen: An Introduction to Clay Colloid Chemistry, 2nd Ed. John Wiley Sons, New York, London, Sydney, Toronto 1977. 318 Seiten, Preis: £ 15.–, $ 25.–.' Berichte der Bunsengesellschaft für physikalische Chemie 82(2): 236-237. [12] Machu, G., et al. (2001). 'Coalescence, torus formation and breakup of sedimenting drops: experiments and computer simulations.' Journal of Fluid Mechanics 447: 299-336. [13] McCave, I. N. (1984). 'Size spectra and aggregation of suspended particles in the deep ocean.' Deep Sea Research Part A. Oceanographic Research Papers 31(4): 329-352. [14] Meakin, P. (1983). 'Formation of Fractal Clusters and Networks by Irreversible Diffusion-Limited Aggregation.' Physical Review Letters 51(13): 1119-1122. [15] Sun, R., et al. (2018). 'Investigating the settling dynamics of cohesive silt particles with particle-resolving simulations.' Advances in Water Resources 111: 406-422. [16] Tambo, N. and H. Hozumi (1979). 'Physical characteristics of flocs—II. Strength of floc.' Water Research 13(5): 421-427. [17] Tambo, N. and Y. Watanabe (1979). 'Physical characteristics of flocs—I. The floc density function and aluminium floc.' Water Research 13(5): 409-419. [18] Wang, Y., et al. (2002). Chapter Two Definition, properties, and classification of muddy coasts. Proceedings in Marine Science. T. Healy, Y. Wang and J.-A. Healy, Elsevier. 4: 9-18. [19] Winterwerp, J. C. (1998). 'A simple model for turbulence induced flocculation of cohesive sediment.' Journal of Hydraulic Research 36(3): 309-326. [20] Winterwerp, J. C. (2004). 'Introduction to the physics of cohesive sediment dynamics in the marine environment.' [21] Witten, T. A. and L. M. Sander (1981). 'Diffusion-Limited Aggregation, a Kinetic Critical Phenomenon.' Physical Review Letters 47(19): 1400-1403. [22] Yang, R. Y., et al. (2000). 'Computer simulation of the packing of fine particles.' Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics 62(3 B): 3900-3908. [23] Zhang, J.-F. and Q.-H. Zhang (2011). 'Lattice Boltzmann simulation of the flocculation process of cohesive sediment due to differential settling.' Continental Shelf Research 31(10, Supplement): S94-S105. | |
| dc.identifier.uri | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/19154 | - |
| dc.description.abstract | 海洋中之雙擴散對流沉降為帶動懸浮物質垂直傳輸之重要機制，其所引起之指狀流將隨時間發展為懸浮顆粒球滴向下沉降，並形成渦環結構，此外，渦環發生瑞利‐泰勒不穩定性將分裂為數個小型環狀。本研究考慮自然界之細小黏附性顆粒，顆粒間可發生絮凝現象形成絮團結構，而絮團相較於單顆顆粒具有較大之沉降速度，因此絮凝現象亦為加速懸浮物質垂直傳輸之關鍵機制。本研究利用尤拉-拉格朗日數值模式模擬球滴沉降至渦環發展過程，且應用絮凝模型，分析在此流況影響下之絮凝時變過程，並討論顆粒慣性、顆粒間作用之凝聚力與顆粒大小所造成的影響，另外亦針對過去文獻中絮凝模型比較其中差異，並發現在高顆粒數密度之下可達到較佳的加速絮凝效果。另一方面，針對渦環發生之瑞利‐泰勒不穩定性，在環形坐標系之下進行線性穩定性分析，若在無黏性假設下，可推導出成長率與波數之色散關係，發現系統中短波長具有較快之成長率。而在本研究之理論推導過程中亦可得知，若在完善考量之下(如考慮渦環形狀與黏滯性)欲求解問題，未來尚有許多努力空間。 | zh_TW |
| dc.description.abstract | Double-diffusive sedimentation is an important mechanism that can enhance vertical transport of suspended materials in the ocean. The resulting sediment-laden finger in double diffusion forms the spherical drop, which then evolves into the vortex ring. Moreover, Rayleigh-Taylor instability can occur in particle-laden rings, generating smaller rings. This study considers fine cohesive particles in nature which can form flocs due to the flocculation process. Flocs are associated with greater settling velocities compared to individual particles. Therefore, flocculation process also plays a key role in vertical transport of suspended matters. In this study, we conduct numerical simulations for the evolution of particle-laden drops and their transition to rings using an Eulerian-Largrangian model. By adding flocculation models, analysis of time-dependent flocculation process under the resulting hydrodynamic influence is made. The effects of the particle inertia, cohesive force, and particle size are discussed. Moreover, differences of flocculation models in the past literature are compared. We found that greater flocculation enhancement can be resulting from higher particle number density. In addition to the numerical study, the Rayleigh-Taylor instability of particle-laden rings is derived through the linear analysis on the toroidal coordinate system. Based on the inviscid assumption, the dispersion relation can be found, showing that short waves has a larger growth rate. Our derivation also shows that the solution with full consideration of the system (e.g., torus shape and viscosity) requires more effort in the future. | en |
| dc.description.provenance | Made available in DSpace on 2021-06-08T01:46:53Z (GMT). No. of bitstreams: 1 U0001-1708202016530100.pdf: 5862615 bytes, checksum: 4753d412a0549c22f66e06d56c129b04 (MD5) Previous issue date: 2020 | en |
| dc.description.tableofcontents | 口試委員審定書 # 誌謝 i 中文摘要 ii Abstract iii 目錄 iv 圖目錄 vii 表目錄 xi Chapter1 緒論 1 1.1 研究背景與動機 1 1.2 文獻回顧 2 1.2.1 雙擴散對流沉降 2 1.2.2 絮凝模型 4 1.3 本文內容概述 8 Chapter2 理論與方法 9 2.1 統御方程式 9 2.2 凝聚力模型(cohesive force model) 10 2.3 絮凝模型(flocculation model) 12 2.4 顆粒傳輸模式 15 2.5 數值方法 16 2.6 模擬配置 17 Chapter3 數值模擬結果 18 3.1 球滴沉降過程簡介 18 3.2 顆粒慣性之影響 23 3.3 顆粒間凝聚力之影響 28 3.4 絮凝情形分析與討論 37 3.4.1 顆粒粒徑之影響 38 3.4.2 顆粒體積分率之影響 45 3.4.3 不同絮凝模型之差異 49 Chapter4 線性穩定性分析 53 4.1 無黏性之線性擾動方程式 54 4.2 正規模態展開 56 4.3 速度解與邊界條件 58 4.3.1 微擾展開 59 4.3.2 O(ε^0) 59 4.3.2.1 速度解 59 4.3.2.2 邊界條件 60 4.3.2.3 色散關係 62 4.3.3 O(ε^1) 63 4.3.3.1 速度解 63 4.3.3.2 邊界條件 65 4.4 考量黏性之簡化分析 67 4.4.1 線性擾動方程式 68 4.4.2 正規模態展開 69 4.4.3 速度解與邊界條件 70 4.4.3.1 速度解 70 4.4.3.2 邊界條件 71 4.4.4 色散關係 73 4.4.5 與模擬結果比較 74 Chapter5 結論與未來工作 75 5.1 結論 75 5.2 未來工作 76 參考文獻 77 附錄 80 | |
| dc.language.iso | zh-TW | |
| dc.subject | 瑞利-泰勒不穩定性 | zh_TW |
| dc.subject | 絮凝 | zh_TW |
| dc.subject | 固液二相流 | zh_TW |
| dc.subject | Rayleigh-Taylor instability | en |
| dc.subject | solid-liquid two-phase flow | en |
| dc.subject | flocculation | en |
| dc.title | 懸浮顆粒渦環中的加速絮凝及線性穩定性分析 | zh_TW |
| dc.title | Flocculation enhancement and linear stability analysis of particle-laden rings | en |
| dc.type | Thesis | |
| dc.date.schoolyear | 108-2 | |
| dc.description.degree | 碩士 | |
| dc.contributor.oralexamcommittee | 陳世楠(Shih-Nan Chen),曾建洲(Chien-Chou Tseng) | |
| dc.subject.keyword | 絮凝,瑞利-泰勒不穩定性,固液二相流, | zh_TW |
| dc.subject.keyword | flocculation,Rayleigh-Taylor instability,solid-liquid two-phase flow, | en |
| dc.relation.page | 81 | |
| dc.identifier.doi | 10.6342/NTU202003805 | |
| dc.rights.note | 未授權 | |
| dc.date.accepted | 2020-08-18 | |
| dc.contributor.author-college | 工學院 | zh_TW |
| dc.contributor.author-dept | 應用力學研究所 | zh_TW |
| 顯示於系所單位： | 應用力學研究所 | |
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