TY - JOUR
T1 - Algebraic turbulence modeling in adiabatic and evaporating annular two-phase flow
AU - Cioncolini, Andrea
AU - Thome, John R.
N1 - Funding Information:
Part of the experimental data used was provided by Professors A. Ghajar, C. Lombardi and R.V.A. Oliemans, who are gratefully acknowledged. A. Cioncolini is supported by the Swiss National Science Foundation (SNSF) under Contract No. 200020-129624/1.
PY - 2011/8
Y1 - 2011/8
N2 - The study considers algebraic turbulence modeling in adiabatic and evaporating annular two-phase flow, focusing in particular on momentum and heat transfer (so-called 'convective boiling') through the annular liquid film. In contrast with single-phase wall-bounded flow theory, shear-driven annular liquid films are assumed here to behave as fluid-bounded flows, mostly interacting with the shearing gas-entrained droplets core flow. Besides providing velocity and temperature profiles through the liquid film, the turbulence model proposed here predicts key parameters such as the average liquid film thickness, the void fraction and the convective boiling heat transfer coefficient with accuracies comparable or better than those of leading design correlations. This turbulence model is part of a unified annular flow modeling suite that includes methods to predict the entrained liquid fraction and the axial frictional pressure gradient. The underlying heat transfer database covers nine fluids (water, two hydrocarbons and six refrigerants) for vertical and horizontal tubes of 1.03-14.4. mm diameter and pressures of 0.1-7.2. MPa. Importantly, this study shows that there appears to be no macro-to-microscale transition when it comes to annular flow. Simply better physical modeling is required to span this range.
AB - The study considers algebraic turbulence modeling in adiabatic and evaporating annular two-phase flow, focusing in particular on momentum and heat transfer (so-called 'convective boiling') through the annular liquid film. In contrast with single-phase wall-bounded flow theory, shear-driven annular liquid films are assumed here to behave as fluid-bounded flows, mostly interacting with the shearing gas-entrained droplets core flow. Besides providing velocity and temperature profiles through the liquid film, the turbulence model proposed here predicts key parameters such as the average liquid film thickness, the void fraction and the convective boiling heat transfer coefficient with accuracies comparable or better than those of leading design correlations. This turbulence model is part of a unified annular flow modeling suite that includes methods to predict the entrained liquid fraction and the axial frictional pressure gradient. The underlying heat transfer database covers nine fluids (water, two hydrocarbons and six refrigerants) for vertical and horizontal tubes of 1.03-14.4. mm diameter and pressures of 0.1-7.2. MPa. Importantly, this study shows that there appears to be no macro-to-microscale transition when it comes to annular flow. Simply better physical modeling is required to span this range.
KW - Algebraic turbulence modeling
KW - Annular two-phase flow
KW - Convective boiling heat transfer
KW - Macroscale
KW - Microscale
KW - Shear-driven liquid film
UR - http://www.scopus.com/inward/record.url?scp=79959539192&partnerID=8YFLogxK
U2 - 10.1016/j.ijheatfluidflow.2011.05.006
DO - 10.1016/j.ijheatfluidflow.2011.05.006
M3 - 文章
AN - SCOPUS:79959539192
SN - 0142-727X
VL - 32
SP - 805
EP - 817
JO - International Journal of Heat and Fluid Flow
JF - International Journal of Heat and Fluid Flow
IS - 4
ER -