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研究生:朱家駿
研究生(外文):Chia-ChunChu
論文名稱:相干性結構在紊流尾流的演進
論文名稱(外文):Evolution of coherent structure in turbulent wake
指導教授:張克勤張克勤引用關係葉思沂
指導教授(外文):Keh-Chin ChangSzu-I Yeh
學位類別:碩士
校院名稱:國立成功大學
系所名稱:航空太空工程學系
學門:工程學門
學類:機械工程學類
論文種類:學術論文
論文出版年:2020
畢業學年度:108
語文別:中文
論文頁數:107
中文關鍵詞:粒子影像測速正交特徵分解大尺度相干性結構衰退參數分析週期均值化處理
外文關鍵詞:PIVPODCoherent structureParametric analysisPeriod-time averaging process
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本研究中利用粒子影像測速儀(Particle Image Velocimetry)於高、低雷諾數(ReD = 3900、9500)之條件下探討二維圓柱近域尾流區之渦漩的產生與脫落過程以及流場中的相關性結構。並加以運用擁有高時間解析及足夠達到統計穩定的樣本數之熱線測速儀(Hot-Wire Anemometry)進行流場測量的驗證,使用正交特徵分解(Proper Orthogonal Decomposition, POD)進行降維分析,並分析如尾流渦漩脫落過程。圓柱尾流存在具有類週期的大尺度相干性結構,並且還會隨著與圓柱的距離所衰減,本研究將使用正交特徵分解及頻譜分析辨認出其大尺度相干性結構,以及其諧波存在的情況。在高速及低速兩組實驗中,由流場的上游(0.5-5d)、中游(5-10d)、下游(10-15d)三段相干性結構能量貢獻來觀察其相干性結構衰退的狀況,可以看到其能量隨著與圓柱的距離增加而減少,不論在高速或低速到達下游時相干性結構的能量貢獻以低於5%。並且使用雷諾分解及週期均值化處理時下游的紊流強度及雷諾應力幾乎沒有差異。
本研究將針對三項參數進行分析。第一項為樣張(sample)的數量,使用6000、8000及10,916張進行各模態能量貢獻的比對,在紊態擾動模態較多的案例中,10,916張是不足的,需要增加更多的樣張。第二項為流場重建所使用模態的數量,使用Kaiser及Sirovich標準觀察流場重建的狀況,發現Kaiser標準無法完整的重現流場細部的擾動值,應使用採用較多模態Sirovich標準。第三項為泰勒尺度與諧波倍頻的關係,發現當諧波倍頻進入到慣性次階區後,將無法在頻譜能量圖中辨認出其諧波倍頻的峰值。
In this research, the generation and shedding processes of vortices in the near wake region and the coherent structure in a flow field are studied at two Reynolds numbers of 3900 and 9500 using proper orthogonal decomposition (POD). POD is a methodology used for the purpose of identifying large-scale eddies (such as Karman vortex) in lower-order modes and for recognizing small scale eddies in high-order modes that contribute to turbulence in the entire flow field. The cylindrical wake possesses a large scale coherent structure, which will be attenuated with distance from the cylinder. POD and a spectrum analysis are used to identify the large scale coherent structure and its harmonics frequency. In the high and low Reynold number experiments, the coherent structure energy contributions of the three regions, which are the upstream (0.5-5d), midstream (5-10d), and downstream (10-15d) regions of the flow field, are used to identify the degradation of the coherent structure. Regardless of whether the Reynolds number is high or low, the energy contribution of the coherent structure is less than 5% in the downstream region. Reynolds decomposition and period-time averaging process exhibit almost no differences in terms of downstream turbulence intensity and Reynolds stress.
Three POD parameters are analyzed in the study. The first parameter was the number of samples, where 6000, 8000, and 10,916 samples were used to compare energy contribution of each mode. However, it reveals that it needs more samples to reach a statistically stationary result. The second parameter was the number of modes used in the reconstruction of the flow field. The Sirovich criterion and the Kaiser criterion were respectively used as the energy contribution bases in the flow field reconstruction. The Kaiser criterion can't reveal the characteristics of small fluctuations. The Sirovich criterion which accumulates more modes is a better choice. The third parameter was the relationship between the Taylor microscale and the harmonic frequency. It was found that when the harmonic frequency falls into the inertia subrange, the peak of the harmonic frequency cannot be identified in the spectrum energy diagram.
摘要 i
Abstract ii
致謝 xix
目錄 xx
表目錄 xxiii
圖目錄 xxiv
符號表 xxvii
第一章 緒論 1
1-1 前言 1
1-2 文獻回顧 2
1-2-1熱線測速(Hot-wire Anemometry, HWA) 3
1-2-2粒子影像測速(Particle Image Velocimetry, PIV) 4
1-2-3 正交特徵分解(Proper Orthogonal decomposition, POD) 7
1-3 研究動機與目的 8
第二章 實驗設備與模型 10
2-1 風洞裝置 10
2-2 測試段模型 11
2-3 移動機構 11
2-4 校正儀器 11
2-4-1 壓力校正器 11
2-4-2 壓力轉換器 12
2-5 熱線測速系統 12
2-5-1 熱線探針 12
2-5-2 熱線測速主機 13
2-5-3 熱線模組 13
2-5-4 資料數據截取系統 14
2-5-5 Stream line應用軟體(Stream Ware) 14
2-6 粒子影像測速系統 14
2-6-1 高速攝影機 14
2-6-2 雷射及光學鏡組 15
2-6-3 追蹤粒子及進料裝置 15
2-6-4 拍攝鏡頭 15
第三章 實驗方法與分析 16
3-1 熱線測速儀 16
3-1-1 實驗原理 16
3-1-2 實驗參數及設定 18
3-2 粒子影像測速法 19
3-2-1 實驗原理 19
3-2-2 實驗參數及設定 20
3-3 實驗數據分析 21
3-3-1 圓柱尾流之紊流特性 21
3-3-2 尺度分解(Decomposition by scale) 24
3-4 誤差分析 27
3-5 參數分析 28
3-5-1 運算時樣張之數量 28
3-5-2 流場重建之模態數量 28
3-5-3 雷諾數及泰勒微尺度分析 29
第四章 結果與討論 30
4-1 實驗可信度分析 31
4-1-1 統計分析 31
4-1-2 顆粒追蹤分析 32
4-1-3 熱線測速與粒子影像測速之比較 32
4-2 正交特徵分解(POD)分析 33
4-3 相干性結構能量衰退分析 35
4-4 參數分析 37
4-4-1運算時樣張之數量 37
4-4-2流場重建之模態數量 38
4-4-3雷諾數及泰勒微尺度分析 39
4-5 週期均值化處理 40
第五章 結論與未來建議 43
參考文獻 45
Arányi, P., Janiga, G., Zähringer, K., & Thévenin, D. (2013). Analysis of different POD methods for PIV-measurements in complex unsteady flows. International journal of heat and fluid flow, 43, 204-211.
Bernero, S., & Fiedler, H. (2000). Application of particle image velocimetry and proper orthogonal decomposition to the study of a jet in a counterflow. Experiments in Fluids, 29(1), S274-S281.
Bohandy, J., Kim, B., & Adrian, F. (1986). Metal deposition from a supported metal film using an excimer laser. Journal of Applied Physics, 60(4), 1538-1539.
Browne, L., Antonia, R., & Shah, D. (1987). Turbulent energy dissipation in a wake. Journal of fluid mechanics, 179, 307-326.
Butcher, D., & Spencer, A. (2019). Cross-correlation of POD spatial modes for the separation of stochastic turbulence and coherent structures. Fluids, 4(3), 134.
Cantwell, B., & Coles, D. (1983). An experimental study of entrainment and transport in the turbulent near wake of a circular cylinder. Journal of fluid mechanics, 136, 321-374.
Chasnov, J. R. (1991). Simulation of the Kolmogorov inertial subrange using an improved subgrid model. Physics of Fluids A: Fluid Dynamics, 3(1), 188-200.
Chuychai, P., Weygand, J., Matthaeus, W., Dasso, S., Smith, C., & Kivelson, M. (2014). Technique for measuring and correcting the Taylor microscale. Journal of Geophysical Research: Space Physics, 119(6), 4256-4265.
Cutler, A., & Bradshaw, P. (1991). A crossed hot-wire technique for complex turbulent flows. Experiments in Fluids, 12(1-2), 17-22.
Hart, D. P. (2000). PIV error correction. Experiments in Fluids, 29(1), 13-22.
Hussain, A. F., & Hayakawa, M. (1987). Eduction of large-scale organized structures in a turbulent plane wake. Journal of fluid mechanics, 180, 193-229.
Kaiser, H. F. (1960). The application of electronic computers to factor analysis. Educational and psychological measurement, 20(1), 141-151.
Keane, R. D., & Adrian, R. J. (1990). Optimization of particle image velocimeters. I. Double pulsed systems. Measurement science and technology, 1(11), 1202.
Kellnerova, R., Kukacka, L., Uruba, V., Jurcakova, K., & Janour, Z. (2012). Detailed analysis of POD method applied on turbulent flow. Paper presented at the EPJ web of conferences.
King, L. V. (1914). XII. On the convection of heat from small cylinders in a stream of fluid: Determination of the convection constants of small platinum wires with applications to hot-wire anemometry. Philosophical transactions of the royal society of London. series A, containing papers of a mathematical or physical character, 214(509-522), 373-432.
Kourta, A., Boisson, H., Chassaing, P., & Minh, H. H. (1987). Nonlinear interaction and the transition to turbulence in the wake of a circular cylinder. Journal of fluid mechanics, 181, 141-161.
Lienhard, J. H. (1966). Synopsis of lift, drag, and vortex frequency data for rigid circular cylinders (Vol. 300): Technical Extension Service, Washington State University Pullman, WA.
Lumley, J. L. (1967). The structure of inhomogeneous turbulent flows. Atmospheric turbulence and radio wave propagation.
Ma, X., Karamanos, G.-S., & Karniadakis, G. (2000). Dynamics and low-dimensionality of a turbulent near wake. Journal of fluid mechanics, 410, 29-65.
Melling, A. (1997). Tracer particles and seeding for particle image velocimetry. Measurement science and technology, 8(12), 1406.
Morkovin, M. (1964). Flow around circular cylinders-a kaleidoscope of challenging fluid phenomena. Paper presented at the Proc. ASME Symp. on Fully Separated Flow, Philadelphia.
Parthasarathy, R., & Faeth, G. (1990). Turbulence modulation in homogeneous dilute particle-laden flows. Journal of fluid mechanics, 220, 485-514.
Pearson, K. (1901). Principal components analysis. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, 6(2), 559.
Perrin, R., Braza, M., Cid, E., Cazin, S., Barthet, A., Sevrain, A., . . . Thiele, F. (2007). Obtaining phase averaged turbulence properties in the near wake of a circular cylinder at high Reynolds number using POD. Experiments in Fluids, 43(2-3), 341-355.
Raffel, M., Willert, C. E., Scarano, F., Kähler, C. J., Wereley, S. T., & Kompenhans, J. (2018). Particle image velocimetry: a practical guide: Springer.
Reynolds, W., & Hussain, A. (1972). The mechanics of an organized wave in turbulent shear flow. Part 3. Theoretical models and comparisons with experiments. Journal of fluid mechanics, 54(2), 263-288.
Roshko, A. (1954). On the development of turbulent wakes from vortex streets.
Roshko, A. (1955). On the wake and drag of bluff bodies. Journal of the aeronautical sciences, 22(2), 124-132.
Schlichting, H. (1979). Boundary Layer Theory, McGraw-Hill, New York, 1979. FIGURE CAPTIONS solid curve displays the exact solution. The difference between the exact solution and the eighth QLM iteration for all t in the figure is less than, 10-10.
Sirovich, L. (1987). Turbulence and the dynamics of coherent structures. I. Coherent structures. Quarterly of applied mathematics, 45(3), 561-571.
Talamelli, A., Westin, K., & Alfredsson, P. H. (2000). An experimental investigation of the response of hot-wire X-probes in shear flows. Experiments in Fluids, 28(5), 425-435.
Tang, S., Djenidi, L., Antonia, R., & Zhou, Y. (2015). Comparison between velocity-and vorticity-based POD methods in a turbulent wake. Experiments in Fluids, 56(8), 169.
Tennekes, H., Lumley, J. L., & Lumley, J. L. (1972). A first course in turbulence: MIT press.
Theofanous, T., & Sullivan, J. (1982). Turbulence in two-phase dispersed flows. Journal of fluid mechanics, 116, 343-362.
Uberoi, M. S., & Freymuth, P. (1969). Spectra of turbulence in wakes behind circular cylinders. The Physics of Fluids, 12(7), 1359-1363.
Van Oudheusden, B., Scarano, F., Van Hinsberg, N., & Watt, D. (2005). Phase-resolved characterization of vortex shedding in the near wake of a square-section cylinder at incidence. Experiments in Fluids, 39(1), 86-98.
Wei, T., & Smith, C. (1986). Secondary vortices in the wake of circular cylinders. Journal of fluid mechanics, 169, 513-533.
Westerweel, J. (1997). Fundamentals of digital particle image velocimetry. Measurement science and technology, 8(12), 1379.
Williamson, C. (1992). The natural and forced formation of spot-like ‘vortex dislocations’ in the transition of a wake. Journal of fluid mechanics, 243, 393-441.
Wu, J., Sheridan, J., Welsh, M., Hourigan, K., & Thompson, M. (1994). Longitudinal vortex structures in a cylinder wake. Physics of Fluids, 6(9), 2883-2885.
Zdravkovich, M. M. (1997). Flow around circular cylinders. Fundamentals, 1, 566-571.
Zhang, Q., Liu, Y., & Wang, S. (2014). The identification of coherent structures using proper orthogonal decomposition and dynamic mode decomposition. Journal of Fluids and Structures, 49, 53-72.
石昌隆. (2015). 圓柱紊態流場之技術探討. 成功大學航空太空工程學系學位論文, 1-108.
沈家緯. (2018). 以粒子影像測速儀與熱線測速儀所得數據進行圓柱近域尾流之紊態流場特性及尺度分析. 成功大學航空太空工程學系學位論文, 1-164.
施柏帆. (2013). PIV 應用於紊流場之定量量測與誤差分析.
黃柏翔. (2019). 藉由粒子影像測速及正交特徵分解辨認近域尾流之大尺度相干性結構. 成功大學航空太空工程學系學位論文, 1-111.
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