請用此 Handle URI 來引用此文件:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/56752
完整後設資料紀錄
DC 欄位 | 值 | 語言 |
---|---|---|
dc.contributor.advisor | 楊馥菱 | |
dc.contributor.author | Hsien-Jen Chen | en |
dc.contributor.author | 陳顯任 | zh_TW |
dc.date.accessioned | 2021-06-16T05:46:15Z | - |
dc.date.available | 2022-08-01 | |
dc.date.copyright | 2014-08-16 | |
dc.date.issued | 2014 | |
dc.date.submitted | 2014-08-11 | |
dc.identifier.citation | 1. Stokes G.G., 1845. “on the theories of the internal friction of fluids in motion” Trans, Camb. Phil. Soc.
2. Brenner, H., 1961. “The slow motion of a sphere through a viscous fluid towards a plane surface” Chem. Eng. Sci. 16,242-251. 3. Cox, R. and Brenner, H., 1967. “The slow motion of a sphere through a viscous fluid towards a plane surface II : Small gap widths, including inertial effects” Chem. Eng. Sci. 22, 1753-1777. 4. Kim, I., Elghobashi, S. and Sirignano, W. A., 1998. “On the equation for spherical-particle motion : effect of Reynolds and acceleration numbers” J. Fluid Mech. 367, 221-253. 5. Mei, R. and Adrian, R. J., 1992. “Flow past a sphere with an oscillation in the free-stream velocity and unsteady drag at finite Reynolds number” J. Fluid Mech. 237, 323-341. 6. Mei, R., 1994. “Flow due to an oscillating sphere and an expression for unsteady drag on the sphere at finite Reynolds number” J. Fluid Mech. 270, 133-174. 7. Michaelides, E. E., 1997. “Review- The transient equation of motion for particles, bubbles, and droplets” Trans, ASME: J. Fluids Eng. 119, 223-247. 8. A.Ambari, B. Gauthier-Manuel and E. Guyon., 1984. “Wall effect on a sphere translating at constant velocity” J. Fluid Mech. 149, 235-253. 9. Chang, E. J. and Maxey, M. R., 1995. “Unsteady flow about a sphere at low to moderate Reynolds number. Part 2. Accelerated motion” J. Fluid Mech. 303, 133-153. 10. Henri P. Gavin., 2013. “The Levenberg-Marquardt meothd for nonlinear least squares curve-fitting problems” Duke University. 11. Clif, R., Grace, J. R., and Weber, M. E.,1978. “Bubbles, drops, and particles” New York: Academic Press. 12. Odar F. and Hamilton S. W., 1964. “Forces on a sphere accelerating in a viscous fluid,” J. Fluid Mech. 18, 302-314. 13. Chi-An Yeh., 2010. “In-situ measurements of unsteady hydrodynamic forces on a solid boundary using strain-gage based transducer” Master Thesis, Mechanical Eng. National Taiwan University. 14. Jung-Hua Lee., 2012. “In-Situ Measurement of Wall Effects on The Hydrodynamic Force for a Solid Sphere in Constant Approach at Low Reynolds Number” Master Thesis, Mechanical Eng. National Taiwan University. 15. Bagchi, P and Balachandar, S., 2003. “Inertial and viscous forces on a rigid sphere in a straining flow at moderate Reynolds numbers” J Fluid Mech. 481, 105-148. 16. Harada S., Tanaka T. and Tsuji Y., 2000. “Fluid force acting on a particle falling toward a wall” Trans. Jpn. Soc. Mech. Eng., Vol. 66, No.649, B(2000), pp.2313-2319. 17. F.-L. Yang., 2010. “ A formula for the wall-amplified added mass coefficient for a solid sphere in normal approach to a wall and its application for such motion at low Reynolds number” Physiscs of fluids 22, 123303. 18. Ganatos, Pfeffer and Weinbaum., 1980. “A strong interaction theory for the creeping motion of a sphere between plane parallel boundaries. Part 2. Parallel motion” J.Fluid Mech, vol, 99, part4, pp. 755-783. 19. Abbad and Souhar., 2004. “Effects of the history force on an oscillating rigid sphere at low Reynolds number” Experiments in Fluids 36, 775-782. 20. Yazan Taamneh., 2011. “CFD Simulations of Drag and Separation Flow Around Ellipsoids” JJMIE, P129-132. | |
dc.identifier.uri | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/56752 | - |
dc.description.abstract | 本論文以系統性實驗探討沉浸球體以等速及等加速運動垂直靠近牆面時所受之流體力,球體運動的雷諾數範圍介於0.21至3.33之間。將實驗球體連接小負載荷重元,球體運動以精密伺服馬達驅動,達成同步力量測。
我們首先驅動球體以等速度運動於水缸槽中心,完成擬穩態阻力(Quasi-Steady Drag)即時量測之校正工作。爾後將球體以相同的運動方式靠近下游水缸牆,水缸牆的存在將會改變流場的邊界條件,進而影響流體運動,使得球體所受流體總動力將有別於無牆時所受之流體總力,流體總力之差異即為牆面效應,以一修正係數表示。 針對擬穩態阻力量測所得之牆面修正係數介於兩種理論預測結果之間,其結果都將隨著球體與牆面間隙減少而單調遞增。當球體以等加速運動近牆時,牆面對於流體附加質量作用力(Added Mass Force)也將造成影響,其牆面修正係數可由勢流理論(Potential Flow Theory)推導而得,將流體總力扣除牆面修正後之擬穩態阻力以及修正流體附加質量作用力之結果,即為牆面修正流體歷史力(Basset History Force)。針對流體歷史力之牆面修正係數,我們擬合實驗結果可得到實驗公式,其結果隨間隙距離減小而單調遞增,隨加速度增加有飽和趨勢。 | zh_TW |
dc.description.abstract | This thesis studies the hydrodynamic force on an immersed sphere approaching in normal direction toward a wall in constant velocity or constant acceleration motion by systematic experiments. The range of Reynolds number covers 0.21 to 3.33. A test sphere connected to a small capacity load cell was driven by a precision servo motor to achieve direct synchronized force measurement with sphere motion.
We firstly drove the sphere at constant velocities and accelerations near the center of a large tank for in-situ calibration and then drove the sphere at identical motion towards the wall. The downstream wall modifies flow boundary condition to result in hydrodynamic force different from the value found in infinite domain. The ratio between the forces with and without downstream wall quantifies the wall effect which is referred as the wall factor. The wall factor measured for quasi-steady force falls between the predictions from two theoretical models and grows monotonically with diminishing gap. Besides of this calibrated quasi-steady drag, wall effect on amplifying the added mass force when the sphere in constant acceleration towards wall was modeled by potential flow theory. These two force components, with respective wall factors, are then subtracted from the total unsteady hydrodynamic force to extrapolate wall-modified history force. An empirical formula was then fitted for the wall factor for history force, which shows dependences on gap and acceleration. | en |
dc.description.provenance | Made available in DSpace on 2021-06-16T05:46:15Z (GMT). No. of bitstreams: 1 ntu-103-R00522121-1.pdf: 5986016 bytes, checksum: b138f95312b1d7fb1f5c9628536ce86a (MD5) Previous issue date: 2014 | en |
dc.description.tableofcontents | 中文摘要 II
Abstract III List of Figure VII List of Table X Nomenclature XI Chapter 1 Introduction 1 1-1 Background and literature review 1 1-2 Objectives 10 Chapter 2 Experimental Facility and Calibration 12 2-1 Tank and sphere 13 2-1.1 Tank and liquid 13 2-1.2 Sphere and measuring device 15 2-2 Motion control system 22 2-3 Data acquisition system 24 2-4 System Calibration 27 2-4.1 Transient duration for a prescribed motion 28 2-4.2 Quasi-steady force with in-situ calibrated coefficients 31 Chapter 3 Hydrodynamic Force without Wall Effect 33 3-1 Relevant force models 34 3-1.1 Quasi-steady force 34 3-1.2 Added mass force 34 3-1.3 History force 35 3-2 Experimental description and results 39 3-2.1 Repeatability 40 3-2.2 Filter via Faster Fourier Transform 42 3-2.3 Experimental results 44 Chapter 4 Wall Effect on Hydrodynamic Force 49 4-1 Existing force models addressing wall effects 49 4-1.1 Wall effect on quasi-steady viscous drag 49 4-1.2 Modified added mass force 52 4-1.3 Wall-modified history force 54 4-2 Experimental description and results 56 4-2.1 Experiments for wall-modified quasi-steady drag 56 4-2.2 Fitting method: Levenberg-Marquardt Algorithm 61 4-2.3 Experiments for wall effect on history force 69 4-3 Discussion 74 Chapter 5 Conclusion 79 Reference 81 | |
dc.language.iso | en | |
dc.title | 低雷諾數近牆之等速度、等加速度固體球其流體力邊界效應之即時量測 | zh_TW |
dc.title | In-Situ Measurement of Wall Effect on the Hydrodynamic Force for a Solid Sphere in Normal Approach at Constant Velocity or Acceleration at Low Reynolds Number | en |
dc.type | Thesis | |
dc.date.schoolyear | 102-2 | |
dc.description.degree | 碩士 | |
dc.contributor.oralexamcommittee | 黃信富,黃美嬌,賴君亮 | |
dc.subject.keyword | 流體動態力即時量測,史托克阻力,流體歷史力,牆面修正係數,流體歷史力之牆面修正係數, | zh_TW |
dc.subject.keyword | in-situ measurement of total hydrodynamic force,history force,Stokes drag,wall amplification,wall correction factor for history force, | en |
dc.relation.page | 82 | |
dc.rights.note | 有償授權 | |
dc.date.accepted | 2014-08-11 | |
dc.contributor.author-college | 工學院 | zh_TW |
dc.contributor.author-dept | 機械工程學研究所 | zh_TW |
顯示於系所單位: | 機械工程學系 |
文件中的檔案:
檔案 | 大小 | 格式 | |
---|---|---|---|
ntu-103-1.pdf 目前未授權公開取用 | 5.85 MB | Adobe PDF |
系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。