Abstract
Visualization of the curvature distorted internal flow in levitated droplets is crucially needed due to the application of droplet dynamics in different areas of engineering, medical sciences, material engineering, and so on. In the present study, an acoustically levitated droplet is focused on, and particle image velocimetry (PIV) is used to visualize and measure flow fields inside the droplet as the measurement technique. Although the flow structure in the levitated droplet is required to understand the internal flow structure of the droplet, it is limited by the low Weber number and curvature distortion when visualization approaches are applied. Researchers have studied droplet levitation technologies; however, there is still less experimental and analytical information about the effect of curvature distortion on the internal flow of a levitated droplet. To understand the flow field inside an acoustically levitated droplet with high accuracy, it is important to experimentally investigate the effect of the parameters that influence the curvature distortion development of the flow inside the droplet. This research aims to visualize and investigate the effect of curvature distortion on the internal flow measurement of a levitated droplet which will lead to the curvature distortion correction. In this study, the effect of curvature distortion on internal flow elucidation was performed based on the refractive index, aspect ratio, surface tension, and diameter. The internal flow fields were experimentally investigated and visualized using the PIV. The experimental results showed that the internal flow curvature distorted increases as the refractive index, aspect ratio, and surface tension increase.
Graphical abstract
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Abbreviations
- AR :
-
Aspect ratios
- \({d}_{\mathrm{o}}\) :
-
Droplet diameter (mm)
- kv :
-
Wave number (m−1)
- PIV:
-
Particle image velocimetry
- \({p}_{n}\) :
-
Sound pressure (Pa)
- PTV:
-
Particle tracking velocimetry
- \({u}_{o}\) :
-
Droplet impact velocity (mm/sec)
- \(\mathrm{We}\) :
-
Weber number
- \(\sigma\) :
-
Surface tension (N/m)
- \(\omega\) :
-
Angular velocity (rad/sec)
- \({\rho }_{l}\) :
-
Fluid density (kg/m3)
References
Abe Y, Hyuga D, Yamada S, Aoki K (2006) Study on internal flow and surface deformation of large droplet levitated by ultrasonic wave. Ann N Y Acad Sci 1077:49–62. https://doi.org/10.1196/annals.1362.050
Boullosa RR, Pérez-López A, Dorantes-Escamilla R (2013) An ultrasonic levitator. J Appl Res Technol 11(6):857–865. https://doi.org/10.1016/S1665-6423(13)71592-X
Eriksson T (2016) Experimental investigation of the internal flow in evaporating and freezing water droplets.
Gao Z, Radner H, Büttner L, Ye H, Li X, Czarske J (2021) Distortion correction for particle image velocimetry using multiple-input deep convolutional neural network and hartmann-shack sensing. Opt Express 29(12):18669. https://doi.org/10.1364/oe.419591
Garafolo NG, Wittmer J, Pathak S (2020) Curvature correction applied to droplets subjected to natural convection for particle image velocimetry. Coll Surf A Physicochem Eng Asp 597(October 2019):124442. https://doi.org/10.1016/j.colsurfa.2020.124442
Horton TJ, Fritsch TR, Kintner RC (1965) Experimental determination of circulation velocities inside drops. Can J Chem Eng 43(3):143–146. https://doi.org/10.1002/cjce.5450430309
Kang KH, Lee SJ, Lee CM, Kang IS (2004) Quantitative visualization of flow inside an evaporating droplet using the ray tracing method. Meas Sci Technol 15(6):1104–1112. https://doi.org/10.1088/0957-0233/15/6/009
Kawakami M, Abe Y, Kaneko A, Yamamoto Y, Hasegawa K (2010) Effect of temperature change on interfacial behavior of an acoustically levitated droplet. Microgravity Sci Technol 22(2):145–150. https://doi.org/10.1007/s12217-009-9167-z
Koukourakis N, Fregin B, König J, Büttner L, Czarske JW (2016) Wavefront shaping for imaging-based flow velocity measurements through distortions using a Fresnel guide star. Opt Express 24(19):22074. https://doi.org/10.1364/oe.24.022074
Kumar SS, Karn A, Arndt REA, Hong J (2017) Internal flow measurements of drop impacting a solid surface. Exp Fluids 58(3):1–9. https://doi.org/10.1007/s00348-016-2293-7
Martins JWAF, da Silva CC, Lessig C, Zäringe K (2018) Ray-tracing based image correction of optical distortion for PIV measurements in packed beds. J Adv Opt Photon 1(2):71–94. https://doi.org/10.32604/jaop.2018.03870
Minor G, Oshkai P, Djilali N (2007) Optical distortion correction for liquid droplet visualization using the ray tracing method: further considerations. Meas Sci Technol. https://doi.org/10.1088/0957-0233/18/11/L01
Mohamad M, Sofwan CM, Mackenzi. Dover, and K. Sefiane. (2018) Experimental investigation of drag coefficient of free-falling deformable liquid gallium droplet. EPJ Appl Phys. https://doi.org/10.1051/epjap/2018180271
Saha A, Basu S, Kumar R (2012) Particle image velocimetry and infrared thermography in a levitated droplet with nanosilica suspensions. Exp Fluids 52(3):795–807. https://doi.org/10.1007/s00348-011-1114-2
Sasaki Y, Kobayashi K, Hasegawa K, Kaneko A, Abe Y (2019) Transition of flow field of acoustically levitated droplets with evaporation. Phys Fluids. https://doi.org/10.1063/1.5124499
Wang G, Anilkumar AV (1996) Oscillations of liquid drops: results from USML-1 experiments in space. J Fluid Mech 308:1–14
Yamamoto Y, Abe Y, Fujiwara A, Hasegawa K, Aoki K (2008) Internal flow of acoustically levitated droplet. Microgravity Sci Technol 20(3–4):277–280. https://doi.org/10.1007/s12217-008-9070-z
Zha K, Busch S, Park C, Miles PC (2016) A novel method for correction of temporally- and spatially-variant optical distortion in planar particle image velocimetry. Meas Sci Technol 27(8):85201. https://doi.org/10.1088/0957-0233/27/8/085201
Acknowledgements
This research was financially supported by University of Rwanda-College of Science and Technology (UR-CST), University of Tsukuba under Japanese Government Scholarship (MEXT). I also appreciate the assistance of Ms. Aiko Tamaki, my co-Thermal fluids control and measurement laboratory member during my research period.
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Gatete, E., Kaneko, A. & Shen, B. The effect of curvature distortion on internal flow measurement of a levitated droplet using PIV. J Vis 27, 33–42 (2024). https://doi.org/10.1007/s12650-023-00949-9
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12650-023-00949-9