Abstract
We show the validity of using a flowing soap film system as a two-dimensional laboratory model of flow past a circular cylinder at low Reynolds numbers through a novel combination of qualitative wake visualizations and quantitative velocity measurements and through a new quantitative method for determining the relative film thickness. We verify the correlation between interference fringe patterns and underlying flow structures by simultaneously obtaining digital particle image velocimetry (DPIV) data and interferograms. We introduce a quantitative soap film thickness measurement method using background-oriented schlieren (BOS) to provide a spatially resolved (relative) thickness field. Vortex cores in the cylinder wake appear as low thickness zones, and the minimum thickness regions identified with BOS are shown to coincide with the vortex centers identified in phase-matched interferograms. The vortex positions and circulations in the soap film correlate well with those reported in the literature for the case of low-Reynolds-number flow past a circular cylinder.
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Notes
A number of other definitions of vortex formation length have been introduced; see, e.g., Yang, Masroor & Stremler (in preparation).
References
Abiven C, Vlachos PP (2020) Super spatio-temporal resolution, digital PIV system for multi-phase flows with phase differentiation and simultaneous shape and size quantification, In: 2002 Proceedings of the ASME IMECE
Abiven C, Vlachos PP, Papadopoulos G (2002) DPIV strategies for resolving high shear and vortical flows, In: 2002 proceedings of the ASME IMECE
Acharya T, Ray AK (2005) Image processing: principles and applications. Wiley, USA
Adrian RJ (2005) Twenty years of particle image velocimetry. Exp Fluids 39(2):159–169
Auliel MI, Hebrero CF, Sosa R, Artana G (2017) Schlieren technique in soap film flows. Exp Fluids 58(5):38. https://doi.org/10.1007/s00348-017-2311-4
Bandi MM, Concha A, Wood R, Mahadevan L (2013) A pendulum in a flowing soap film. Phys Fluids 25:41702
Başca CA, Takş M, Brad R (2005) Randomized Hough transform for ellipse detection with result clustering, In: EUROCON 2005 - The International Conference on Computer as a Tool, 2: 1397–1400
Berger E (1964) The determination of hydrodynamic parameters of a Karman eddy street from hot-wire measurements at low Reynolds numbers. Zeitschrift Fiir Flugwissenschaften 12:41
Bhattacharya S, Charonko JJ, Vlachos PP (2017) Stereo-particle image velocimetry uncertainty quantification. Meas Sci Technol 28(1):015301
Bhattacharya S, Charonko JJ, Vlachos PP (2018) Particle image velocimetry (PIV) uncertainty quantification using moment of correlation (MC) plane. Meas Sci Technol 29(11):115301
Brindise MC, Vlachos PP (2017) Proper orthogonal decomposition truncation method for data denoising and order reduction. Exp Fluids. https://doi.org/10.1007/s00348-017-2320-3
Chen YN (1972) Fluctuating lift forces of the Karman vortex streets on single circular cylinders and in tube bundles: part 1—the vertex street geometry of the single circular cylinder. J Manuf Sci Eng Trans ASME 94:603
Chen Y, Fried E (2013) Stability and bifurcation of a soap film spanning an elastic loop. J Elast 116(1):75–100. https://doi.org/10.1007/s10659-013-9458-x
Chomaz JM (2001) The dynamics of a viscous soap film with soluble surfactant. J Fluid Mech 442:387
Chomaz JM, Cathalau B (1990) Soap films as two-dimensional classical fluids. Phys Rev A 41:2243
Chomaz JM, Costa M (1998) Thin Film Dynamics. Free Surface Flows. Springer, Vienna, pp 45–99
Chong MS, Perry AE, Cantwell BJ (1990) A general classification of three-dimensional flow fields. Phys Fluids A 2:765
Couder Y (1984) Two-dimensional grid turbulence in a thin liquid film. J Phys Lettres 45:353
Couder Y, Basdevant C (1986) Experimental and numerical study of vortex couples in two-dimensional flows. J Fluid Mech 173:225
Couder Y, Chomaz JM, Rabaud M (1989) On the hydrodynamics of soap films. Phys D Nonlinear Phenom 37:384
Eckstein A, Vlachos PP (2009a) Digital particle image velocimetry (DPIV) robust phase correlation. Meas Sci Technol 20(5):55401
Eckstein A, Vlachos PP (2009b) Assessment of advanced windowing techniques for digital particle image velocimetry (DPIV). Meas Sci Technol 20:75402
Eckstein AC, Charonko J, Vlachos P (2008) Phase correlation processing for DPIV measurements. Exp Fluids 45(3):485–500
Etebari A, Vlachos PP (2005) Improvements on the accuracy of derivative estimation from DPIV velocity measurements. Exp Fluids 39:1040
Fujiwara H (2007) Spectroscopic ellipsometry: principles and applications. Wiley, USA
Georgiev D, Vorobieff P (2002) The slowest soap-film tunnel in the Southwest. Rev Sci Instrum 73:1177
Gharib M, Derango P (1989) A liquid film (soap film) tunnel to study two-dimensional laminar and turbulent shear flows. Phys D 37:406
Green RB, Gerrard JH (1993) Vorticity measurements in the near wake of a circular cylinder at low Reynolds numbers. J Fluid Mech 246:675
Griffin OM (1971) The unsteady wake of an oscillating cylinder at low reynolds number. J Appl Mech Trans ASME 38:729
Griffin OM (1995) A note on bluff body vortex formation. J Fluid Mech 284:217
Griffin OM, Ramberg SE (1974) The vortex-street wakes of vibrating cylinders. J Fluid Mech 66:553
Griffin OM, Votaw CW (1972) The vortex street in the wake of a vibrating cylinder. J Fluid Mech 55:31
Horváth VK, Cressman JR, Goldburg WI, Wu XL (2000) Hysteresis at low reynolds number: onset of two-dimensional vortex shedding. Phys Rev E 61:R4702
Hum YC, Lai KW, Mohamad Salim MI (2014) Multiobjectives bihistogram equalization for image contrast enhancement. Complexity 20(2):22–36
Hunt JCR (1987) Vorticity and vortex dynamics in complex turbulent flows. Trans Can Soc Mech Eng 11(1):21–35
Illingworth J, Kittler J (1988) A Survey of the Hough Transform. Comput Vision, Graph Image Process 44(1):87–116
Jaensson N, Vermant J (2018) Tensiometry and rheology of complex interfaces. Curr Opin Colloid Interf Sci 37:136–150
Jeong J, Hussain F (1995) On the identification of a vortex. J Fluid Mech 285:69
Jia LB, Yin XZ (2008) Passive oscillations of two tandem flexible filaments in a flowing soap film. Phys Rev Lett 100(22):228104
Jia L-B, Yin X-Z (2009) Response modes of a flexible filament in the wake of a cylinder in a flowing soap film. Phys Fluids 21(10):101704
Jia L, Xiao Q, Wu H, Wu Y, Yin X (2015) Response of a flexible filament in a flowing soap film subject to a forced vibration. Phys Fluids 27:17101
Kellay H (2017) Hydrodynamics experiments with soap films and soap bubbles: a short review of recent experiments. Phys Fluids 29(11):111113
Kellay H, Wu XL, Goldburg WI (1995) Experiments with turbulent soap films. Phys Rev Lett 74:3975
Kim I, Mandre S (2017) Marangoni Elasticity of Flowing Soap Films. Phys Rev Fluids 2(8):082001
Kovasznay LSG (1949) Hot-Wire Investigation of the Wake behind cylinders at low Reynolds numbers. Proc r Soc London Ser a Math Phys Sci 198:174
Leavers VF (1993) Which Hough transform? CVGIP Image Underst 58:250
MaskellE C (1963) A Theory of the Blockage Effects on, Bluff Bodies and Stalled Wings in a Closed Wind Tunnel, Reports Memo. 1
Matsui T, Okude M (1980) Rearrangement of Kármán Vortex Street at Low Reynolds Numbers. XVth International Congress of Theoretical and Applied Mechanics. University of Toronto, Toronto, pp 1–27
Mysels KJ, Frankel S, Shinoda K (1959) Soap films: studies of their thinning and a bibliography, Pergamon Press
Nishioka M, Sato H (1978) Mechanism of determination of the shedding frequency of vortices behind a cylinder at low Reynolds numbers. J Fluid Mech 89:49
Raffel M (2015) Background-oriented schlieren (BOS) techniques. Exp Fluids 56:60
Raffel M, Willert CE, Wereley ST, Kompenhans J, Willert S, Wereley ST, Kompenhans J (2007) Particle image velocimetry: a practical guide. Springer, Berlin, Heidelberg
Rai-Choudhury P, Benton JL, Shroder DK, Shaffner TF (1997) Diagnostic techniques for semiconductor materials and devices, in diagnostic techniques for semiconductor materials and devices, Vol. 3322
Rajendran L, Zhang J, Bane S, Vlachos P (2020a) Uncertainty-based weighted least squares density integration for background-oriented schlieren. Exp Fluids 61:239
Rajendran LK, Zhang J, Bhattacharya S, Bane SPM, Vlachos PP (2020b) Uncertainty quantification in density estimation from background-oriented schlieren measurements. Meas Sci Technol 31(5):054002
Rivera M, Wu XL (2000) External dissipation in driven two-dimensional turbulence. Phys Rev Lett 85:976
Rivera M, Vorobeiff P, Ecke R (1998) Turbulence in flowing soap films: velocity, vorticity, and thickness fields. Phys Rev Lett 81:1417
Rosenhead L (1930) An Experimental Investigation of the Flow behind Circular Cylinders in Channels of Different Breadths. Proc R Soc Lond Series A, Contain Papers Math Phys Charact 129(809):115–135. https://doi.org/10.1098/rspa.1930.0146
Roushan P, Wu XL (2005) Structure-based interpretation of the Strouhal-Reynolds number relationship. Phys Rev Lett 94:54504
Rutgers MA, Wu X, Bhagavatula R, Petersen AA, Goldburg WI (1996) Two-dimensional velocity profiles and laminar boundary layers in flowing soap films. Phys Fluids 8:2847
Sallet DW (1969) On the spacing of Karman vortices. J Appl Mec 36(2):370–372. https://doi.org/10.1115/1.356465
Schaefer JW, Eskinazi S (1959) An analysis of the vortex street generated in a viscous fluid. J Fluid Mech 6:241
Schnipper T, Andersen A, Bohr T (2009) Vortex wakes of a flapping foil. J Fluid Mech 633:411
Soloff SM, Adrian RJ, Liu Z-C (1997) Distortion compensation for generalized stereoscopic particle image velocimetry. Meas Sci Technol 8(12):1441–1454. https://doi.org/10.1088/0957-0233/8/12/008
Tchoukov P, Yang F, Xu Z, Dabros T, Czarnecki J, Sjöblom J (2014) Role of asphaltenes in stabilizing thin liquid emulsion films. Langmuir 30:3024
Thom A (1933) The flow past circular cylinders at low speeds. Proc R Soc A Math Phys Eng Sci 141(845):651–669
Timme A (1957) On the velocity distribution in eddies. Fundamentals 25:205
Venkatakrishnan L, Meier GEA (2004) Density measurements using the background oriented schlieren technique. Exp Fluids 37:237
Von Kármán T (1912) On the mechanism of resistance produced by moving body in liquid, Nachrichtungen Des Gesellschaft Wiss
Vorobieff P, Ecke RE (1999) Cylinder wakes in flowing soap films. Phys Rev E 60:2953
Vorobieff P, Rivera M, Ecke RE (1999) Soap film flows: statistics of two-dimensional turbulence. Phys Fluids 11:2167
Vorobieff P, Rivera M, Ecke RE (2001) Imaging 2D Turbulence. J vis 3:323
Walton ETS (1928) The formation of vortices behind a cylinder moving through a fluid. Sci Proc Royal Dublin Soc 18:521–534
Wen C-Y, Lin C-Y (2001) Two-dimensional vortex shedding of a circular cylinder. Phys Fluids 13:557
West GS, Apelt CJ (1982) The effects of tunnel blockage and aspect ratio on the mean flow past a circular cylinder with Reynolds numbers between 104 and 105. J Fluid Mech 114:361
Westerweel J, Scarano F (2005) Universal outlier detection for PIV data. Exp Fluids 39:1096
Wieneke B (2005) Stereo-PIV using self-calibration on particle images. Exp Fluids 39:267
Williamson CHK, Brown GL (1998) A series in 1/√ Re to represent the Strouhal-Reynolds number relationship of the cylinder wake. J Fluids Struct 12:1073
Wu XL, Levine R, Rutgers M, Kellay H, Goldburg WI (2001) Infrared technique for measuring thickness of a flowing soap film. Rev Sci Instrum 72:2467
Wu MH, Wen CY, Yen RH, Weng MC, Wang AB (2004) Experimental and numerical study of the separation angle for flow around a circular cylinder at low reynolds number. J Fluid Mech 515:233
Yang W, Stremler MA (2019) Critical spacing of stationary tandem circular cylinders at Re≈ 100. J Fluids Struct 89:49–60. https://doi.org/10.1016/j.jfluidstructs.2019.02.023
Yang TS, Wen CY, Lin CY (2001) Interpretation of color fringes in flowing soap films. Exp Therm Fluid Sci 25:141
Yonghong X, Qiang J (2002) A new efficient ellipse detection method, proceedings - international conference on. Pattern Recogn 16:957–960
Yuen HK, Princen J, Illingworth J, Kittler J (1990) Comparative study of Hough transform methods for circle finding. Image vis Comput 8:71
Zdravkovich MM (1997) Flow around circular cylinders. Fundamentals 1:566
Zhang J, Childress S, Libchaber A, Shelley M (2000) Flexible filaments in a flowing soap film as a model for one-dimensional flags in a two-dimensional wind. Nature 408:835
Acknowledgements
The authors thank Emad Masroor for his assistance in reviewing the historical works on the wake of cylinders.
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Javad Eshraghi was involved in methodology, software, formal analysis, data curation, investigation, visualization, and writing—original draft. Lalit K. Rajendran was involved in methodology, software, investigation, and writing—original draft. Wenchao Yang was involved in methodology and writing—review and editing. Mark A. Stremler was involved in conceptualization, methodology, investigation, supervision, and writing—original draft, review, and editing. Pavlos P. Vlachos was involved in conceptualization, methodology, investigation, supervision, project administration, funding acquisition, and writing—original draft, review, and editing.
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Eshraghi, J., Rajendran, L.K., Yang, W. et al. On flowing soap films as experimental models of 2D Navier–Stokes flows. Exp Fluids 62, 162 (2021). https://doi.org/10.1007/s00348-021-03238-z
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DOI: https://doi.org/10.1007/s00348-021-03238-z