An analysis of experimental data and prediction methods for two-phase frictional pressure drop and flow boiling heat transfer in micro-scale channels

Journal Article · Sun Oct 15 00:00:00 EDT 2006 · Experimental Thermal and Fluid Science

DOI:https://doi.org/10.1016/J.EXPTHERMFLUSCI.2006.01.006· OSTI ID:20824167

Ribatski, Gherhardt; Wojtan, Leszek; Thome, John R ^[1]

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1. Laboratory of Heat and Mass Transfer (LTCM), Faculty of Engineering Science (STI), Ecole Polytechnique Federale de Lausanne (EPFL), Station 9, CH-1015 Lausanne (Switzerland)

Experimental results for two-phase frictional pressure drop and flow boiling heat transfer in micro-scale channels were obtained from the literature. The extensive pressure drop database comprises both diabatic and adiabatic results covering eight fluids, mass velocities from 23 to 6000kg/m{sup 2}s and vapor qualities up to 1. These data were carefully analyzed and compared against 12 two-phase frictional pressure drop prediction methods, including both macro- and micro-scale methods. Overall, the methods by Muller-Steinhagen and Heck and by Mishima and Hibiki, as well as the homogenous model, using the two-phase viscosity definition proposed by Cicchitti and coworkers, provide the most accurate predictions. However, they worked poorly at vapor qualities higher than 0.5 where annular, partial dryout and mist flow patterns would be expected. Similarly, a large database for micro-scale flow boiling heat transfer for eleven fluids covering mass velocities from 100 to 800kg/m{sup 2}s, reduced pressures from 0.03 to 0.77 and heat fluxes from 5 to 180kW/m{sup 2} were compared against three recently proposed micro-scale and one well-known macro-scale heat transfer prediction method. Although some heat transfer trends were captured by the methods, in general they poorly predicted the database. This is not surprising since an analysis of the trends of the experimental results revealed large discrepancies between different data sets, even at similar experimental conditions, and no present method could capture such contrasting trends. The study concludes that the 3-zone model proposed by Thome and coworkers based on the transient conduction through an evaporating liquid film seems to be the most promising approach to predict heat transfer coefficients in micro-scale channels but is still not sufficiently developed to use as a general design tool. (author)

• OSTI ID: 20824167
• Journal Information: Experimental Thermal and Fluid Science, Vol. 31, Issue 1; Other Information: Elsevier Ltd. All rights reserved; ISSN 0894-1777
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
PRESSURE DROP
TWO-PHASE FLOW
BOILING
HEAT TRANSFER
CALCULATION METHODS
ACCURACY
DUCTS