Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Non-intrusive measurements of bubble size and velocity

  • 214 Accesses

  • 23 Citations


A non-intrusive measuring technique based on video-imaging has been developed for the measurement of bubble size, velocity and frequency. Measurements carried out with this method have been compared to those obtained by an optimized phase-Doppler system in standard configuration, for a wide range of bubble sizes produced from single injectors in a quiescent environment. The two measuring techniques have yielded velocities and frequencies that are in very good agreement while the size of spherical bubbles was consistently measured by both methods. The phase-Doppler system was also used to size oblate-spheroidal bubbles moving with their equatorial plane parallel to the scattering plane, yielding measurements reasonably close to the average radius of curvature of the bubbles in the neighborhood of the equatorial plane, as calculated from the video-imaging data. Both methods were used for detailed velocity measurements of the bubble-stream in the neighborhood of the injector tip. The observed bubble-velocity variation with the distance from the injector tip does not always display the usual increasing trend leading into the terminal velocity. When injection conditions are near the transition from discrete to jet injection mode and the bubbles are small, the latter decelerate into a terminal velocity due to direct interaction of successive bubbles at the injector tip. The measured terminal velocities of bubble-chains for a variety of bubble sizes and injection frequencies, are successfully predicted by using a far-field wake approximation to account for the drafting effect which is responsible for bubble-chain velocities higher than those of single bubbles.

This is a preview of subscription content, log in to check access.


  1. Brauer H (1971) Grundlagen der Einphasen- und Mehrphasenströmung. Sauerfländer, Aarau und Frankfurt a.M.

  2. Brena de la Rosa A; Sankar SV; Weber BJ; Wang G; Bachalo WD (1989) A theoretical and experimental study of the characterization of bubbles using light scattering interferometry. Int. Symp. on Cavitation Inception, FED-Vol 89, ASME No. H00558, pp 63–72

  3. Clift R; Grace JR; Weber ME (1978) Bubbles, drops and particles. Academic press, NY

  4. Davis GE (1955) Scattering of light by an air bubble in water. J Opt Soc Am 45: 572–581

  5. Danel F; Vermeille H; Guilloud JC; Jacquet A; Delhaye JM (1983) High-speed multiple spark cameras for gas-liquid two-phase flows studies, measuring techniques in gas-liquid two-phase flows. Proceedings IUTAM, Nancy, France, July 5–8

  6. Durst F; Melling A; Whitelaw JH (1981) Principles and practice of laser doppler anemometry, 2nd edition

  7. Durst FM; Zaré (1975) Laser doppler measurements in two-phase flows, Proceedings of the LDA symposium, Copenhagen, Denmark, pp 403–429

  8. Durst F; Schonung B; Selanger K; Winter M (1986) Bubble-driven liquid flows. J. Fluid Mech 170: 53–82

  9. Durst F; Taylor AMKP; Whitelaw JH (1984) Experimental and numerical investigation of bubble-driven laminar flow in an axisymmetric vessel. Int J Multiphase Flow 10: 557–569

  10. Gaudin AM (1957) Flotation, 2nd ed., McGraw-Hill, New York

  11. Hardalupas Y; Taylor AMKP; Whitelaw JH (1987) Measurements in heavily-laden dusty jets with phase-doppler anemometry. Proceedings 2nd Int. Symp. on Transport Phenomena in Turbulent Flows

  12. Hawighorst A (1983) Drop size measurement in a vertical gas-liquid flow, in “Measuring Techniques in Gas-Liquid Two-Phase Flows”, Proceedings of the International Union of Theoretical and Applied Mechanics, Nancy, France, July 5–8, 1983

  13. Mueller A; Hugi C (1989) Design of an instrument for measuring density, size and velocity of rising air bubbles. Proceedings IAHR instrumentation workshop, Canada Center for Inland Waters, Burlington, Ontario, 16–18 August, 1989

  14. Naqwi AA; Durst F; Liu XZ (1990) Characterization of multiphase flows using an extended phase-doppler anemometer. Proceedings 5th Int. Symp. on Application of Laser Anemometry in Fluid Mechanics, Lisbon

  15. Naqwi AA; Durst F (1992) Light scattering applied to LDA and PDA measurements Part 2: computational results and their discussion, Particle and Particle Systems Characterization 9: 66–80

  16. Peterson DA; Tankin RS; Bankoff SG (1983) Holographic measurements of bubble size and velocity in a three-phase system, in “Measuring Techniques in Gas-Liquid Two-Phase Flows”, Proceedings of the International Union of Theoretical and Applied Mechanics. Nancy, France, July 5–8, 1983

  17. Saffman M; Buchhave P; Tanger H (1984) Simultaneous measurement of size, concentration and velocity to spherical particles by a laser doppler method. The Second International Symposium on Applications of Laser Anemometry to Fluid Mechanics. Lisbon, Portugal, 2–4 July, 1984

  18. Tollmien W (1931) Handbuch der Experimentalischen Physik, Vol. IV, pt. 1, Leipzig

  19. Tsuge H (1986) Hydrodynamics of bubble formation from submerged orifices, In: “Encyclopedia of Fluid Mechanics”. N.P. Cheremisinoff (Ed) Vol. 3, pp 192–232

  20. Ungut A; Grehan G; Gouesbet G (1981) Comparisons between geometrical optics and Lorenz-Mie theory. Applied Optics 2911–2918

  21. White F (1974) Viscous Fluid Flow, McGraw-Hill

Download references

Author information

Additional information

The authors gratefully acknowledge the support from the Louisiana Board of Reagents through grants LEQSF (1991-1992)-ENH-31 and LEQSF (1990-1992)-RD-A-07, ARCO Chemical Company through it's University Grants Program and the National Science Foundation through its Graduate Fellowship Program.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Tassin, A.L., Nikitopoulos, D.E. Non-intrusive measurements of bubble size and velocity. Experiments in Fluids 19, 121–132 (1995).

Download citation


  • Equatorial Plane
  • Bubble Size
  • Average Radius
  • Terminal Velocity
  • Injection Mode