Numerical and experimental studies on flow condensation in hydrophilic microtubes

Sadaghiani, Abdolali Khalili (2021) Numerical and experimental studies on flow condensation in hydrophilic microtubes. Applied Thermal Engineering, 197 . ISSN 1359-4311 (Print) 1873-5606 (Online)

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Microchannels have increasingly been used to miniaturize heat transfer equipment, improve energy efficiency, and minimize heat transfer fluid inventory. A fundamental understanding of condensation in microscale will yield far-reaching benefits for the different areas of industry. In this study, microtubes with inner diameters of 250, 500, 600, and 900 µm were used to investigate the effect of microtube diameter, inlet quality, and mass flux on the liquid/vapor interface near the wall boundaries in condensing flow. After validation with the experimental results, a transient numerical model (based on the Volume of Fluid approach) was developed to investigate the hydrothermal properties of condensing such as bubble dynamics, flow map transitions, transient interface shear force, and temperature on flow condensation performance in terms of heat transfer coefficient and pressure drop. The liquid film thickness, slug velocity, and location of transition from annular flow to slug flow inside the microtube were characterized for different microtubes, and the resultant alteration in condensation flow heat transfer and pressure drop is discussed in detail. Using non-dimensional analysis, a flow map was constructed and compared with the available flow maps for flow condensation in microchannels. The obtained results indicated that the interfacial characteristics of condensing flow in microtubes with hydraulic diameters lower than 500 µm are majorly different from those with D > 500 µm.
Item Type: Article
Uncontrolled Keywords: Dynamic contact angle; Flow condensation; Flow pattern; Liquid film thickness, Bubble dynamics; Liquid/vapor interface; Non-dimensional analysis
Divisions: Faculty of Engineering and Natural Sciences
Sabancı University Nanotechnology Research and Application Center
Depositing User: Abdolali Khalili Sadaghiani
Date Deposited: 30 Aug 2022 13:03
Last Modified: 30 Aug 2022 13:03

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