Microlayer in nucleate boiling seen as Landau-Levich film with dewetting and evaporation

• Main Authors: Tecchio, Cassiano, Zhang, Xiaolong, Cariteau, Benjamin, Zalczer, Gilbert, Cabarrocas, Pere Roca i, Bulkin, Pavel, Charliac, Jérôme, Vassant, Simon, Nikolayev, Vadim S
• Format: Journal Article
• Language: English
• Published: 16-06-2023
• Subjects: Physics - Fluid Dynamics
• DOI: 10.48550/arxiv.2306.09838

Both experimental and theoretical studies on the microscale and fast physical
phenomena occurring during the growth of vapor bubbles in nucleate pool boiling
are reported. The focus is on the liquid film of micrometric thickness
(``microlayer'') that can form between the heater and the liquid-vapor
interface of a bubble on the millisecond time scale. The microlayer strongly
affects the macroscale heat transfer and is thus important to be understood. It
is shown that the microlayer can be seen as the Landau-Levich film deposited by
the bubble foot edge during its receding when the bubble grows. The microlayer
profile measured with white-light interferometry, the temperature distribution
over the heater, and the bubble shape were observed with synchronized
high-speed cameras. The microlayer consists of two regions: a ridge near the
contact line followed by a longer and flatter part. The ridge could not be
measured because of the intrinsic limitation of interferometry, which is
analyzed. The simulations show that the ridge grows over time due to collection
of liquid at contact line receding, the theoretical dynamics of which agrees
with the experiment. The flatter part of the microlayer is bumped and its
physical origin is explained.