Prof. Yuan WANG

College of Aerospace Science and Engineering, National University of Defense Technology, Changsha, Hunan 410073, China.

E-mail: y.wang@nudt.edu.cn

Bio

Yuan Wang, Ph.D., Associate Professor. College of Aerospace Science and Engineering, National University of Defense Technology.

She obtained her Ph.D. in Chemical Engineering from the University of Edinburgh in 2011 and joint NUDT ever since. Her research interests include aero-engine thermal protection, icing and anti-icing, and heat and mass transfer in phase-change processes. She has published over 90 academic papers and has been authorized 16 national patents. She is selected for the High-level Innovative Talent Training Program of Hunan Province and National University of Defense Technology.

Title

Experimental observation of thermal pattern transition across an evaporating meniscus

Abstract

Evaporation of curved liquid surfaces or sessile droplets is a complex thermo-fluidic phenomenon that has been extensively studied due to its wide range of applications in fields such as material processing, cooling systems, and microfluidics. The thermal behaviors of an evaporating meniscus significantly impact the performance of high-heat-flux components in fields such as data centers, supercomputers, etc. We investigate the thermal patterns and convection mechanisms in an evaporating ethanol meniscus. Infrared thermography is employed to capture the temperature evolution of the meniscus formed in quartz cuvettes with different inner diameters. High-resolution spatiotemporal thermal images are obtained. Four distinct convection stages are identified. Analysis reveals that larger cuvettes with thinner films suppress fractal “croissant-shaped” thermal cells while enhancing the Marangoni stress-dominated radial migration of small-scale cells. The Marangoni-to-Rayleigh numbers ratio exhibits weak temperature dependence but can be used to calculate the liquid layer thickness threshold below which Marangoni effects govern interfacial transport.