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完整後設資料紀錄
DC 欄位 | 值 | 語言 |
---|---|---|
dc.contributor.advisor | 戴璽恆 | |
dc.contributor.author | Yu-An Li | en |
dc.contributor.author | 李祐安 | zh_TW |
dc.date.accessioned | 2021-06-17T07:03:35Z | - |
dc.date.available | 2022-08-02 | |
dc.date.copyright | 2019-08-02 | |
dc.date.issued | 2019 | |
dc.date.submitted | 2019-07-29 | |
dc.identifier.citation | 1. Alavian, V. 1986 Behavior of density currents on an incline. J. Hydraul. Eng. 112(1), 27-42.
2. Britter, R. E., Linden, P. F. 1980 The motion of the front of a gravity current travelling down an incline. J.Fluid Mech. 586, 1-39. 3. Beghin, P., Hopfinger, E. J. & Britter, R. E. 1981 Gravitational convection from instantaneous sources on inclined boundaries. J. Fluid Mech. 107, 407-422. 4. Chawdhary, S., Khosronejad, A., Christodoulou, G., Sotiropoulos, F. 2018 Large eddy simulation of density current on sloping beds. International Journal of Heat and Mass Transfer. 120, 1374-1385. 5. Dai, A., Ozdemir, C. E., Cantero, M. I., Balachandar, S. 2012 Gravity currents from instantaneous sources down a slope. J. Hydraul. Eng. 138(3), 237-246. 6. Dai, A. 2013 Experiments on gravity currents propagating on different bottom slopes. J. Fluid Mech. 731, 117-141. 7. Dai, A. 2014 Non-Boussinesq gravity currents propagating on different bottom slopes. J. Fluid Mech. 741, 658-680. 8. Huppert, H. E. & Simpson, J. E. 1980 The slumping of gravity currents. J. Fluid Mech. 99, 785-799. 9. Hopfinger, E. J. 1983 Snow avalanche motion and related phenomena. Annu. Rev. Fluid Mech. 15, 47-76. 10. Hauenstein, W., Dracos, T. 1984 Investigation of plunging density currents generated by inflows in lakes. J. Hydraul. Res. 22(3), 157-179. 11. Morton, B. R., Taylor, G. I., Turner, J. S. 1956 Turbulent gravitational convection from maintained and instantaneous sources. Proc. Roy. Soc. A 234, 1-23. 12. Maxworthy, T., Nokes, R. I. 2007 Experiments on gravity currents propagating down slopes. Part 1. The release of a fixed volume of heavy fluid from an enclosed lock into an open channel. J. Fluid Mech. 584, 433-453. 13. Maxworthy, T. 2010 Experiments on gravity currents propagating down slopes. Part 2. The evolution of a fixed volume of fluid released from closed locks into a long, open channel. J. Fluid Mech. 647, 27-51. 14. Ross, A. N., Linden, P. F., Dalziel, S. B. 2002 A study of three-dimensional gravity currents on a uniform slope. J. Fluid Mech. 453, 239-261. 15. Simpson, J. E. & Britter, R. E. 1979 The dynamics of the head of a gravity current advancing over a horizontal surface. J. Fluid Mech. 94, 477-495. 16. Simpson, J. E. 1997 Gravity currents in the enviroment and the laboratory, 2nd Edn. Cambridge University Press. 17. Turner, J. S. 1962 The starting plume in neutral surroundings. J. Fluid Mech. 13, 356-368. 18. Tsihrintzis, V. A., Alavian, V. 1996 Spreading of three-dimensional inclined gravity plumes. J. Hydraul. Res. 34(5), 695-711. | |
dc.identifier.uri | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/72685 | - |
dc.description.abstract | 本論文探討連續入流之異重流於底床坡度0度到15度上進行三維運動之實驗。當重流體被釋放於一斜面時,異重流流域形貌會類似於橢圓之形狀,由於在主流方向受重力驅動,並且在側向方向與環境流體混合,異重流會沿著斜坡運動並往側邊進行擴散。異重流前端之擴散形式取決於初始浮力通量、底床坡度以及重流體與環境流體間之密度差,在我們的實驗中,密度差設定在5.2%,屬於Non-Boussinesq之流動型態,藉由因次分析理論來說明異重流之流動特性。有趣的是,當底床坡度在6度以上時,角度對無因次參數π1=b/xf影響相對較小,始終處於相同的階數,其中b為異重流最大寬度,xf為異重流最前端之位置。另外,可以根據xf~b或是xf~〖((∆p/ρ0)g)〗^(-3/5)之關係做線性回歸得到虛擬原點之位置,而虛擬原點位置會隨著流量增大往上游移動。此外,角度對頭部高度成長及前端速度的影響比初始浮力通量還要來的大,但流量增加對於異重流側向的擴散有重要的影響。 | zh_TW |
dc.description.abstract | Experiments for unconfined 3D gravity currents produced from continuous inflows propagating down an inclined bottom 0˚≦θ≦15˚ have been investigated. While the denser fluid is released propagating on the sloping surface, a gravity plume analogous to the elliptical shape is generated. The plume travels downslope and spreads laterally due to the gravitational force in streamwise direction and the entrainment in spanwise direction. The formation of front spreading depends on the initiating buoyancy flux, the slope of the bottom and the density difference between the heavy fluid and the ambient fluid. In our experiment the relative density difference is specified as the Non-Boussinesq flow regime, nearly 5.2%. Theoretical expressions were carried out to demonstrate the flow characteristics in experiments based on the dimensional analysis. Interestingly, on θ≧6˚ the effect of slope angle is relatively minimal, as indicated by the shape factor, π1=b⁄xf , that is consistently at the same order, where b is the maximum width of spreading plume and xf is location of effluent front. It is also known that the location of inlet point source, i.e. the virtual origin, could be determined based on linear regressions from the plot of xf~b or from the power-law relations between front location and relative density, xf~〖((∆p/ρ0 )g)〗^(-3/5). The location of virtual origin becomes further upstream as the flow rate increases. Additionally, from the relation xf~h, where h is the thickness of current head, it is noted that the growth of head thickness and the front velocity have a profound effect on the bottom slope rather than the buoyancy flux. With respect to the evolving flow motion, our results also showed that the growth of lateral spreading was dominated by the inlet flow rate. | en |
dc.description.provenance | Made available in DSpace on 2021-06-17T07:03:35Z (GMT). No. of bitstreams: 1 ntu-108-R06525073-1.pdf: 4442342 bytes, checksum: 2d0565f4a8c9eb18d7a72669d4a7a193 (MD5) Previous issue date: 2019 | en |
dc.description.tableofcontents | 致謝………………………………………………………………………I
中文摘要…………………………………………………………………II Abstract…………………………………………………………………III 圖目錄……………………………………………………………………VI 表目錄……………………………………………………………………X 第一章 緒論…………………………………………………………………1 1.1 前言…………………………………………………………………1 1.2 文獻回顧………………………………………………………………1 第二章 研究方法……………………………………………………………3 2.1 實驗設備介紹…………………………………………………………3 2.1.1 實驗設備及量測儀器……………………………………………3 2.1.2 影像拍攝相關裝置………………………………………………4 2.2 實驗方法……………………………………………………………5 2.3 實驗流程……………………………………………………………7 2.3.1 拍攝異重流運動行為流程…………………………………………8 2.3.2 定點量測異重流密度變化流程……………………………………9 2.4 實驗初始條件………………………………………………………10 2.5影像處理及尺寸量測方法……………………………………………11 第三章 實驗結果與分析……………………………………………………13 3.1 因次分析……………………………………………………………13 3.2 θ=12°、6°、3°之定性分析…………………………………………14 3.3 定量分析……………………………………………………………27 3.3.1 頭端速度分析……………………………………………………27 3.3.2 無因次參數分析…………………………………………………33 3.4 綜合討論與比較………………………………………………………46 3.4.1同角度不同流量之實驗影像比較…………………………………46 3.4.2同流量不同角度之實驗影像比較…………………………………47 3.4.3同流量同角度不同密度差之實驗影像比較…………………………48 第四章 結論………………………………………………………………49 參考文獻…………………………………………………………………54 附錄1……………………………………………………………………56 附錄2……………………………………………………………………60 | |
dc.language.iso | zh-TW | |
dc.title | 連續入流之異重流在平面斜坡運動與分析 | zh_TW |
dc.title | Gravity currents generated by a constant inflow on an unbounded slope | en |
dc.type | Thesis | |
dc.date.schoolyear | 107-2 | |
dc.description.degree | 碩士 | |
dc.contributor.oralexamcommittee | 丁肇隆,李政賢,吳清森 | |
dc.subject.keyword | 異重流,坡度,連續入流,密度差,無因次參數, | zh_TW |
dc.subject.keyword | gravity currents,unconfined slope,constant inflow,density difference,dimensionless parameter, | en |
dc.relation.page | 68 | |
dc.identifier.doi | 10.6342/NTU201902121 | |
dc.rights.note | 有償授權 | |
dc.date.accepted | 2019-07-30 | |
dc.contributor.author-college | 工學院 | zh_TW |
dc.contributor.author-dept | 工程科學及海洋工程學研究所 | zh_TW |
顯示於系所單位: | 工程科學及海洋工程學系 |
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