PIV EXPERIMENTAL STUDY ON STATISTICAL FRACTAL CHARACTERISTICS OF UNIFORM MOMENTUM ZONES IN TURBULENT BOUNDARY LAYER
-
摘要: 均匀动量区(UMZs)作为动量相近的局部区域成为新的湍流拟序结构成员, 研究其统计特性与变化规律、分析其成因、研究其与其它湍流结构的内在关联, 是深入认识壁湍流的重要途径. 本文通过粒子图像测速系统(PIV)测量得到了具有高时空分辨率的湍流边界层流法向流场, 对UMZs分区、界面位置等进行了统计, 并基于瞬态流场分析了UMZs分界线与发卡涡(包)为主的湍流结构的位置关联, 结果发现: UMZs流向速度概率密度函数(PDF)和界面厚度的统计分析呈现普适的分形特性, 且不受湍流/非湍流界面(TNTI)和雷诺数的影响; 瞬态流场UMZs数目在湍流间歇区较大, 而湍流结构发展充分、层次丰富时的瞬态流场UMZs数目却较少; 壁湍流涡包结构内多个发卡涡的空间分布规律决定了UMZs的统计分形特征; 在近壁UMZs分界线向湍流结构存在区域集中靠拢, 在外区UMZs分界线穿越展向涡核, 正向涡旋导致UMZs分界线在法向上的聚集, 反向涡旋引起UMZs分界线在流向上产生分离.
-
关键词:
- 均匀动量区(UMZs) /
- 分形特性 /
- 湍流结构 /
- 发卡涡包
Abstract: Uniform momentum zones (UMZs), as local regions with similar momentum, become a new member of turbulence coherent structures. To study statistical characteristics, variation rules, its root causes and internal relationship with other turbulent structures about UMZs are an important way to understand wall turbulence. In this paper, the streamwise and wall-normal flow field of turbulent boundary with high spatio-temporal resolution was measured by time-resolved particle image velocimetry (TRPIV) system, statistical analysis was conducted on the partition and interface position of the UMZs. The position correlation between the UMZs boundary and the turbulent structure dominated by hairpin vortices (packets) was analyzed as well. The results revealed that the statistical analysis of streamwise velocity PDF and interface thickness of UMZs showed universal fractal characteristic, not affected by TNTI interfaces and Reynolds numbers. There are more UMZs number in the turbulent intermittent zone, and less UMZs number in instantaneous flow fields with well-developed turbulent structures with rich layers. The spatial distribution law of hairpin vortex packet determines the statistical fractal characteristics of the UMZs. The UMZs boundary near the wall converges towards the turbulent structure, while the UMZs boundary crosses the spanwise vortex core in the outer region. Forward spanwise vortex caused the aggregation of UMZs boundary in the wall-normal direction, while reverse spanwise vortex produced separation of UMZs boundary in the streamwise direction. -
图 8 L-FOV下不同数目均匀动量区流向速度概率分布
Figure 8. Probability distribution of streamwise velocity in different numbers of UMZS under L-FOV
图 9 S-FOV下不同数目均匀动量区流向速度概率分布
Figure 9. Probability distribution of streamwise velocity in different numbers of UMZs under S-FOV
图 10 不同雷诺数下不同数目均匀动量区流向速度概率分布
Figure 10. Probability distribution of streamwise velocity with different UMZs numbers under different Reynolds numbers
图 11 不同数目均匀动量区流向速度剖面下分区界面平均高度(虚线为UMZs分界线对应法向高度)
Figure 11. Average height of partition interface under streamwise velocity profiles with different UMZs numbers (The dashed lines represent the wall-normal heights of UMZs boundary)
图 12 不同数目均匀动量区与湍流结构发展状态的关系(图a, d, g和j分别为图b, e, h和k对应时刻的全场流向速度PDF, c, f, i和l分别为图b, e, h和k中蓝色虚线与TNTI包围涡包部分对应流向速度的PDF)
Figure 12. The relationship between the different numbers of UMZs and the development state of turbulent structures (Figures a, d, g, and j respectively show the full field streamwise velocity PDF at the corresponding time of Figures b, e, h, and k. Figures c, f, i, and l respectively show the PDF of the streamwise velocity corresponding to the blue dashed line and TNTI surrounding parts in Figures b, e, h, and k)
图 13 受涡结构影响的UMZs边界线变化(Ⅰ类为UMZs分界线与湍流结构分布一致, Ⅱ类为正向展向涡旋影响下的UMZs边界线, Ⅲ类为反向展向涡旋影响下的UMZs边界线)
Figure 13. Changes in UMZs boundary affected by vortex structure (Class I represents the UMZs boundary consistent with the distribution of turbulent structures, Class II represents the UMZs boundary affected by forward spanwise vortices, and Class III represents the UMZs boundary affected by reverse spanwise vortices)
图 14 涡包结构与UMZs分界线位置关系
Figure 14. Position relationship between vortex packets structure and UMZs boundary
表 1 湍流边界层的基本流动参数
Table 1. Basic flow parameters of turbulent boundary layer
参数 工况1 工况2 工况3 ${U_\infty }$(m/s) 0.149 0.227 0.272 $\delta $(mm) 48.7 45.6 43.4 $\theta $(mm) 4.72 4.42 4.21 ${u_\tau }$ (mm/s) 6.8 10.0 12.3 ${ {{\rm{Re}}} _\delta }$ 7045 10050 11461 ${ {{\rm{Re}}} _\theta }$ 683 974 1112 ${ {{\rm{Re}}} _\tau }$ 322 443 519 
下载: 导出CSV
-
[1] Adrain R J, Meinhart C D, D, TC. Vortex organization in the outer region of the turbulent boundary layer. Journal of Fluid Mechanics, 2000, 422: 1-54 [2] Zhang J-H, Li B-H, Su J-B, et al. Influence of synthetic jet on uniform momentum zones. International Journal of Heat and Fluid Flow, 2023, 101: 109131 doi: 10.1016/j.ijheatfluidflow.2023.109131 [3] Chen X, Chung Y M, Wan M. Uniform-momentum zones in a turbulent pipe flow. Journal of Fluid Mechanics, 2019, 884: A25 [4] Chen X, Chung Y M, Wan M. The uniform-momentum zones and internal shear layers in turbulent pipe flows at Reynolds numbers up to Reτ = 1000. International Journal of Heat and Fluid Flow, 2021, 90: 108817 doi: 10.1016/j.ijheatfluidflow.2021.108817 [5] Anderson W, Salesky S T. Uniform momentum zone scaling arguments from direct numerical simulation of inertia-dominated channel turbulence. Journal of Fluid Mechanics, 2020, 906(408): A8 [6] Eisma J, Westerweel J, Ooms G, et al. Interfaces and internal layers in a turbulent boundary layer. Physics of Fluids, 2015, 27(5): 055103 doi: 10.1063/1.4919909 [7] De Silva C M, Hutchins N, Marusic I. Uniform momentum zones in turbulent boundary layers. Journal of Fluid Mechanics, 2016, 786: 309-331 doi: 10.1017/jfm.2015.672 [8] Michael Heisel, Charitha M. De Silva, Nicholas Hutchins, et al. On the mixing length eddies and logarithmic mean velocity profile in wall turbulence[J]. Journal of Fluid Mechanics, 2020, 887: R1 [9] Hearst R J, De Silva C M, Dogan E, et al. Uniform-momentum zones in a turbulent boundary layer subjected to freestream turbulence. Journal of Fluid Mechanics, 2021, 915(509): A109 [10] Bross M, Scharnowski S, Kähler C J. Large-scale coherent structures in compressible turbulent boundary layers. Journal of Fluid Mechanics, 2021, 911(402): A2 [11] Scarano F, Jacob M C, Carbonneau X, et al. On the turbulent boundary layer over a flat plate at moderate Reynolds numbers. Physics of Fluids, 2022, 34(11): 115150 doi: 10.1063/5.0124498 [12] M. M, Neamtu-Halic, Dominik Krug, et al. Connecting the time evolution of the turbulence interface to coherent structures[J]. Journal of Fluid Mechanics, 2020, 898: A3 [13] Gampert M, Boschung J, Hennig F, et al. The vorticity versus the scalar criterion for the detection of the turbulent/non-turbulent interface. Journal of Fluid Mechanics, 2014, 750: 578-596 doi: 10.1017/jfm.2014.280 [14] 李思成, 吴迪, 崔光耀等. 低雷诺数沟槽表面湍流非湍流界面特性的实验研究. 力学学报, 2020, 52(6): 1632-1644 (Li Sicheng, Wu Di, Cui Guangyao, et al. Experimental study on turbulent and non turbulent interface characteristics of groove surface at low reynolds number. Chinese Journal of Theoretical and Applied Mechanics, 2020, 52(6): 1632-1644 (in Chinese)(Li Sicheng, Wu Di, Cui Guangyao, et al. Experimental study on turbulent and non turbulent interface characteristics of groove surface at low reynolds number. Chinese Journal of Theoretical and Applied Mechanics, 2020, 52(06): 1632-1644 (in Chinese) ). [15] Chauhan K, Philip J, De Silva C M, et al. The turbulent/non-turbulent interface and entrainment in a boundary layer. Journal of Fluid Mechanics, 2014, 742: 119-151 doi: 10.1017/jfm.2013.641 [16] Reuther N, Kähler C J. Evaluation of large-scale turbulent/non-turbulent interface detection methods for wall-bounded flows. Experiments in Fluids, 2018, 59(7): 121 doi: 10.1007/s00348-018-2576-2 [17] Long Y, Wu D, Wang J. A novel and robust method for the turbulent/non-turbulent interface detection. Experiments in Fluids, 2021, 62(7): 138 doi: 10.1007/s00348-021-03231-6 [18] Wang K, Jiang N. Influence of uniform momentum zones on frictional drag within the turbulent boundary layer. Chinese Physics B, 2021, 30(3): 034703 doi: 10.1088/1674-1056/abc7a6 [19] Laskari A, De Kat R, Hearst R J, et al. Time evolution of uniform momentum zones in a turbulent boundary layer. Journal of Fluid Mechanics, 2018, 842: 554-590 doi: 10.1017/jfm.2018.126 [20] 王超伟, 王康俊, 李彪辉等. 湍流边界层等动量区演化机理的实验研究. 力学学报, 2021, 53(3): 761-772 (Wang Chaowei, Wang Kangjun, Li Biaohui, et al. Experimental study on the evolution mechanism of the constant momentum region of the turbulent boundary layer. Chinese Journal of Theoretical and Applied Mechanics, 2021, 53(3): 761-772 (in Chinese)(Wang Chaowei, Wang Kangjun, Li Biaohui, et al. Experimental study on the evolution mechanism of the constant momentum region of the turbulent boundary layer. Chinese Journal of Theoretical and Applied Mechanics, 2021, 53(03): 761-772 (in Chinese) ). [21] Heisel Michael, De Silva Charitha M, Katul Gabriel G, et al. Self-similar geometries within the inertial subrange of scales in boundary layer turbulence. Journal of Fluid Mechanics, 2022, 942(433): A33 [22] De Silva Charitha M, Philip Jimmy, Hutchins Nicholas, et al. Interfaces of uniform momentum zones in turbulent boundary layers. Journal of Fluid Mechanics, 2017, 820: 451-478 [23] Wu K-T, Tsai C W, Wu M-J. Probabilistic Characterization of Sweep and Ejection Events in Turbulent Flows and Its Implications on Sediment Transport. Water Resources Research, 2022, 58(5): 030417 [24] Tang Z, Fan Z, Chen L, et al. Outer-layer structure arrangements based on the large-scale zero-crossings at moderate Reynolds number. Physics of Fluids, 2021, 33(8): 085121 doi: 10.1063/5.0057036 [25] Heisel Michael, Sullivan Peter P, Katul Gabriel G, et al. Turbulence Organization and Mean Profile Shapes in the Stably Stratified Boundary Layer:Zones of Uniform Momentum and Air Temperature. Boundary-Layer Meteorology, 2022, 186: 533-565 [26] 胡建军, 朱晴, 王美达等. 近距离下射流冲击平板PIV实验研究. 力学学报, 2020, 52(5): 1350-1361 (Hu Jianjun, Zhu Qing, Wang Meida, et al. Experimental study on PIV of jet impact on flat plate at close range. Chinese Journal of Theoretical and Applied Mechanics, 2020, 52(5): 1350-1361 (in Chinese)(Hu Jianjun, Zhu Qing, Wang Meida, et al. Experimental study on PIV of jet impact on flat plate at close range. Chinese Journal of Theoretical and Applied Mechanics, 2020, 52(05): 1350-1361 (in Chinese) ). [27] 何江, 符松. 竖直平板间自然对流大尺度相干结构的POD分析. 力学学报, 2003(4): 385-392 (He Jiang, Fu Song. POD analysis of large-scale coherent structure of Natural convection between vertical plates. Chinese Journal of Theoretical and Applied Mechanics, 2003(4): 385-392 (in Chinese) doi: 10.3321/j.issn:0459-1879.2003.04.001(He Jiang, Fu Song. POD analysis of large-scale coherent structure of Natural convection between vertical plates. Chinese Journal of Theoretical and Applied Mechanics, 2003, (04): 385-392 (in Chinese) ). doi: 10.3321/j.issn:0459-1879.2003.04.001 [28] 权基琢鋆, 姜楠, 唐湛棋. 拉格朗日方法下立方体诱导拟序结构的实验. 力学学报, 2013, 45(5): 772-776 (Quan Jizhuojun, Jiang Nan, Tang Zhanqi. Experiment of cube induced coherent structure based on Lagrangian method. Chinese Journal of Theoretical and Applied Mechanics, 2013, 45(5): 772-776 (in Chinese) doi: 10.6052/0459-1879-12-361(Quan Jizhuojun, Jiang Nan, Tang Zhanqi. Experiment of cube induced coherent structure based on Lagrangian method. Chinese Journal of Theoretical and Applied Mechanics, 2013, 45(05): 772-776 (in Chinese) ). doi: 10.6052/0459-1879-12-361 [29] Pan C, Wang J, Zhang C. Identification of lagrangian coherent structures in the turbulent boundary layer. Science in China Series G:Physics, Mechanics and Astronomy, 2009, 52(2): 248-257 doi: 10.1007/s11433-009-0033-1 [30] Tian H, Yi X, Xu F, et al. Lagrangian-based spatial-temporal topological study on the evolution and migration of coherent structures in wall turbulence. Acta Mechanica Sinica, 2022, 38(1): 321465 doi: 10.1007/s10409-021-09006-1 [31] 唐湛棋, 姜楠. 圆柱尾迹影响旁路转捩末期发卡涡涡包的研究. 力学学报, 2011, 43(6): 1037-1042 (Tang Zhanqi, Jiang Nan. A study on the influence of cylindrical wake on the seizure vortex packet at the end of bypass transition. Chinese Journal of Theoretical and Applied Mechanics, 2011, 43(6): 1037-1042 (in Chinese)(Tang Zhanqi, Jiang Nan. A study on the influence of cylindrical wake on the seizure vortex packet at the end of bypass transition. Chinese Journal of Theoretical and Applied Mechanics, 2011, 43(06): 1037-1042 (in Chinese) ). [32] 申俊琦, 王建杰, 潘翀. 平板湍流边界层瞬时摩擦阻力的光学测量和统计分析. 气体物理, 2020, 5(5): 13-23 (Shen Junqi, Wang Jianjie, Pan Chong. Optical measurement and statistical analysis of instantaneous frictional resistance of turbulent boundary layer on a flat plate. Gas Physics, 2020, 5(5): 13-23 (in Chinese) doi: 10.19527/j.cnki.2096-1642.0873(Shen Junqi, Wang Jianjie, Pan Chong. Optical measurement and statistical analysis of instantaneous frictional resistance of turbulent boundary layer on a flat plate. Gas Physics, 2020, 5(05): 13-23 (in Chinese) ). doi: 10.19527/j.cnki.2096-1642.0873 [33] Schlatter P, ÖrlÜ R. Assessment of direct numerical simulation data of turbulent boundary layers. Journal of Fluid Mechanics, 2010, 659: 116-126 doi: 10.1017/S0022112010003113 [34] Xu F, Zhong S, Zhang S. Statistical analysis of vortical structures in turbulent boundary layer over directional grooved surface pattern with spanwise heterogeneity. Physics of Fluids, 2019, 31(8): 085110 doi: 10.1063/1.5110048 [35] Kang Y-D, Koo B. Experimental Study of Energy Contribution by Coherent Structures in a Turbulent Boundary Layer. Journal of Coastal Research, 2021, 114(sp1): 579-583 [36] Li S, Jiang N, Yang S, et al. Coherent structures over riblets in turbulent boundary layer studied by combining time-resolved particle image velocimetry (TRPIV), proper orthogonal decomposition (POD), and finite-time Lyapunov exponent (FTLE). Chinese Physics B, 2018, 27(10): 104701 doi: 10.1088/1674-1056/27/10/104701 [37] Tian H, Zhang J, Jiang N, et al. Effect of hierarchical structured superhydrophobic surfaces on coherent structures in turbulent channel flow. Experimental Thermal and Fluid Science, 2015, 69: 27-37 doi: 10.1016/j.expthermflusci.2015.07.018 [38] Jodai Y, Elsinga G E. Experimental observation of hairpin auto-generation events in a turbulent boundary layer. Journal of Fluid Mechanics, 2016, 795: 611-633 doi: 10.1017/jfm.2016.153 -
下载:
点击查看大图
图(14) / 表(1)
计量
- 文章访问数: 30
- HTML全文浏览量: 10
- PDF下载量: 9
- 被引次数: 0
