Adiabatic two-phase frictional pressure drops in microchannels

Journal Article · Sun Jul 15 04:00:00 EDT 2007 · Experimental Thermal and Fluid Science

DOI:https://doi.org/10.1016/J.EXPTHERMFLUSCI.2006.07.001· OSTI ID:20885459

Revellin, Remi; Thome, John R ^[1]

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1. EPFL, STI ISE LTCM, ME Gl 464, Station 9, CH-1015 Lausanne (Switzerland)

Two-phase pressure drops were measured over a wide range of experimental test conditions in two sizes of microchannels (sight glass tubes 0.509 and 0.790 mm) for two refrigerants (R-134a and R-245fa). Similar to the classic Moody diagram in single-phase flow, three zones were distinguishable when plotting the variation of the two-phase friction factor versus the two-phase Reynolds number: a laminar regime for Re{sub TP} < 2000, a transition regime for 2000 {<=} Re{sub TP} < 8000 and a turbulent regime for Re{sub TP} {>=} 8000. The laminar zone yields a much sharper gradient than in single-phase flow. The transition regime is not predicted well by any of the prediction methods for two-phase frictional pressure drops available in the literature. This is not unexpected since only a few data are available for this region in the literature and most methods ignore this regime, jumping directly from laminar to turbulent flow at Re{sub TP} = 2000. The turbulent zone is best predicted by the Mueller-Steinhagen and Heck correlation. Also, a new homogeneous two-phase frictional pressure drop has been proposed here with a limited range of application. (author)

• OSTI ID: 20885459
• Journal Information: Experimental Thermal and Fluid Science, Journal Name: Experimental Thermal and Fluid Science Journal Issue: 7 Vol. 31; ISSN 0894-1777; ISSN ETFSEO
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
CORRELATIONS
FORECASTING
FRICTION FACTOR
GLASS
LAMINAR FLOW
PRESSURE DROP
REFRIGERANTS
REYNOLDS NUMBER
TUBES
TURBULENT FLOW
TWO-PHASE FLOW
VARIATIONS
ZONES