Experiments in Fluids

, Volume 42, Issue 4, pp 563–573 | Cite as

Probabilistic determination of two-phase flow regimes in horizontal tubes utilizing an automated image recognition technique

  • Emad W. JassimEmail author
  • Ty A. Newell
  • John C. Chato
Research Article


Probabilistic two-phase flow map data is experimentally obtained for R134a at 25.0, 35.0, and 49.7°C, R410A at 25.0°C, mass fluxes from 100 to 600 kg/m2-s, qualities from 0 to1 in 8.00, 5.43, 3.90, and 1.74 mm I.D. single, smooth, adiabatic, horizontal tubes in order to extend probabilistic two-phase flow map modeling techniques to single tubes. A new web camera based flow visualization technique utilizing an illuminated diffuse striped background was used to enhance images, detect fine films, and aid in the automated image recognition process developed in the present study. This technique has an average time fraction classification error of less than 0.01.


Flow Regime Mass Flux Time Fraction Annular Flow Black Stripe 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

List of symbols


pressure drop (Pa)


unit length (m)


observed time fraction (−)


flow quality (−)

Greek symbols


void fraction (−)



pertaining to the annular flow regime


pertaining to the liquid flow regime


pertaining to the intermittent flow regime


pertaining to the vapor flow regime



The authors would like to thank the Air Conditioning and Research Center (ACRC) at the University of Illinois for their financial support. The authors would also like to thank Matthew Alonso, Francisco Garcia, Sarah Brewer, Frank Lam for aiding in the data acquisition, and Wen Wu for his assistance with Visual Basic.


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Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Emad W. Jassim
    • 1
    Email author
  • Ty A. Newell
    • 1
  • John C. Chato
    • 1
  1. 1.Department of Mechanical Science and EngineeringUniversity of IllinoisUrbanaUSA

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