TY - JOUR

T1 - Modification of the Lockhart-Martinelli model for prediction two-phase frictional pressure drop in microchannels taking into account gas quasi-compressibility effect

AU - Dementyev, Yu A.

AU - Vozhakov, I. S.

AU - Degtyarev, S. A.

AU - Chashina, M. S.

AU - Chinnov, E. A.

N1 - Текст о финансировании The study was supported by the Russian Science Foundation (project no. 22-19-20090) and the Government of the Novosibirsk region (agreement no. p-13).

PY - 2025/5/1

Y1 - 2025/5/1

N2 - Currently, several models and their modifications exist for predicting two-phase pressure drop due to friction in microchannels. However, none of analytical these models account for the compressibility of gases, which becomes significant in channels with heights of around 500 μm. This study demonstrates the applicability of the Lockhart-Martinelli approach for two-phase flows in long microchannels (for L >> Dh), using a slit microchannel with a height of 51.2 μm, width of 10 mm, and length of 50 mm, while considering gas quasi-compressibility effect. Single- and two-phase pressure drops have been experimentally measured where HFE-7100 and water have been utilized as the working liquids, and nitrogen as the working gas. The results reveal a nonlinear dependence of pressure drop on gas mass flux, indicating pressure-dependent gas density in the range of pressure drop from 1.8 to 92.4 kPa for single-phase gas flow and 1.78 to 228.62 kPa for two-phase flow. The experimental two-phase interaction parameter (Chisholm parameter) has been determined, describing its evolution mechanisms with variations in liquid and gas mass fluxes. A comparison of the Chisholm parameter with that of incompressible fluids has been also provided. A modified Lockhart-Martinelli separated flow model has been proposed for laminar flows of both liquid and gas for predicting two-phase frictional pressure drop, implicitly accounting for gas pressure drop in the microchannel. It has been shown, that this model accurately predicts the Chisholm parameter within 10 % accuracy, consistent with the described mechanisms of parameter evolution.

AB - Currently, several models and their modifications exist for predicting two-phase pressure drop due to friction in microchannels. However, none of analytical these models account for the compressibility of gases, which becomes significant in channels with heights of around 500 μm. This study demonstrates the applicability of the Lockhart-Martinelli approach for two-phase flows in long microchannels (for L >> Dh), using a slit microchannel with a height of 51.2 μm, width of 10 mm, and length of 50 mm, while considering gas quasi-compressibility effect. Single- and two-phase pressure drops have been experimentally measured where HFE-7100 and water have been utilized as the working liquids, and nitrogen as the working gas. The results reveal a nonlinear dependence of pressure drop on gas mass flux, indicating pressure-dependent gas density in the range of pressure drop from 1.8 to 92.4 kPa for single-phase gas flow and 1.78 to 228.62 kPa for two-phase flow. The experimental two-phase interaction parameter (Chisholm parameter) has been determined, describing its evolution mechanisms with variations in liquid and gas mass fluxes. A comparison of the Chisholm parameter with that of incompressible fluids has been also provided. A modified Lockhart-Martinelli separated flow model has been proposed for laminar flows of both liquid and gas for predicting two-phase frictional pressure drop, implicitly accounting for gas pressure drop in the microchannel. It has been shown, that this model accurately predicts the Chisholm parameter within 10 % accuracy, consistent with the described mechanisms of parameter evolution.

KW - Compressibility

KW - Flow patterns

KW - Pressure drop

KW - Slit microchannel

KW - Two-phase flow

UR - https://www.mendeley.com/catalogue/7769a57c-888f-3101-8ba8-8fc5acfc613b/

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85213516377&origin=inward&txGid=fba6c83c4215e85b2857c36990e51a8f

U2 - 10.1016/j.ijheatmasstransfer.2024.126605

DO - 10.1016/j.ijheatmasstransfer.2024.126605

M3 - Article

VL - 240

JO - International Journal of Heat and Mass Transfer

JF - International Journal of Heat and Mass Transfer

SN - 0017-9310

M1 - 126605

ER -