Abstract
This work entails experimental measurement and theoretical modeling of heat transfer coefficient (HTC) for annular flow boiling in upward and downward flow configurations. The working fluid used was HFE-7000 and experimental measurements were carried out inside a sapphire tube coated externally with indium-tin-oxide (ITO) for Joule heating. The range of vapor quality, mass flux, and heat flux investigated were 0.15 − 0.7, 75–400 kg/(m2s), and 0.5 − 3.0 W/cm2, respectively. Theoretical models for predicting HTC in upward and downward flows were developed using heat-flux-dependent wall shear stress correlations and roll-wave-velocity-based interfacial damping function. It was found that interfacial damping depends on the Reynolds number of the liquid film. The proposed models predicted over 96% of the measured HTC within ±20% in both upward and downward flows and reproduced the heat flux dependence of the HTC. The models also predicted over 96% of the measured liquid film thickness within ±30% in both upward and downward flows.
Acknowledgments
Petroleum Technology Development Fund (PTDF) is acknowledged for the PhD grant funding of P. Ayegba. The European Space Agency (ESA) and the French Space Agency (CNES) through the GDR 2799 Micropesanteur Fondamentale et Appliquée are acknowledged for the financial support in the building of the experimental set-up.
Disclosure statement
No potential conflict of interest was reported by the authors.
Additional information
Funding
Notes on contributors
Paul Onubi Ayegba
Paul O. Ayegba is a PhD student at Institut National Polytechnique de Toulouse, France/Institut de Mécanique des Fluides de Toulouse, France. His PhD subject is in fluid mechanics. He was a recipient of the J.W. Fulbright Visiting Scholar Grant at the University of California Berkeley (2018–2019) and a recipient of the Petroleum Technology Development Fund (PTDF) PhD Scholarship (2019–2022). He has a good academic research profile with over 10 publications as well as field work experience.
Julien Sebilleau
Julien Sebilleau is an Assistant Professor at the University of Toulouse and Researcher at the Institute of Fluid Mechanics in Toulouse (IMFT). He obtained his PhD in 2009 in Paris and joined IMFT in 2011. His main research topics are two-phase flow in normal and microgravity conditions, phase change, wetting, and capillary flows. He is involved in several national and international networks and projects on two-phase flow for space applications and nuclear industry. He has authored 39 publications in peer-reviewed journals or proceedings of international conferences.
Catherine Colin
Catherine Colin is a Professor at the University of Toulouse and Researcher at the Institute of Fluid Mechanics in Toulouse (IMFT). She obtained her PhD in 1990 in Toulouse and joined IMFT as CNRS researcher. She became full Professor in 2002. Her main research topics are two-phase flow in normal and microgravity conditions, bubble dynamics, breakup and coalescence, turbulence modeling, pool, and convective boiling. She is involved in several national and international networks and projects on two-phase flow for space applications and nuclear industry. She has authored 150 publications in peer-reviewed journals or proceedings of international conferences and 15 keynote lectures in international conferences. She was associate editor of Experimental Thermal and Fluid Science (2010–2018) and is associate editor of International Journal of Multiphase flows since 2018. She is involved in the scientific committees or co-chair of several international conferences (International Conference on Multiphase Flow, International Conference on Boiling and Condensation Heat Transfer, Experimental Heat Transfer Fluid Flow and Thermodynamics). She was Vice Chair in charge of research at the Polytechnic National Institute of Toulouse (2016–2020).