THESIS
2023
1 online resource (101 volume (unpaged)) : illustrations (some color)
Abstract
Interfacial phase change is of fundamental importance to many industrial processes
and in daily life. In respect to this, research focusing on the interaction between surfaces and
phase change phenomena had been attracting many scientists and engineers to investigate
since the early days, and will be focused on the future research. Phase change phenomena are
fundamental to many industrial heat transfer process, such as condensation and boiling,
which are fundamental process determining the efficiency of steam turbine power generation.
On the other hand, freezing phenomenon occurring in cold area affects the safety of machine
operations and even daily life. Researchers had devoted themselves in the understanding of
icing physics and contributed to the design of different anti-icing strat...[
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Interfacial phase change is of fundamental importance to many industrial processes
and in daily life. In respect to this, research focusing on the interaction between surfaces and
phase change phenomena had been attracting many scientists and engineers to investigate
since the early days, and will be focused on the future research. Phase change phenomena are
fundamental to many industrial heat transfer process, such as condensation and boiling,
which are fundamental process determining the efficiency of steam turbine power generation.
On the other hand, freezing phenomenon occurring in cold area affects the safety of machine
operations and even daily life. Researchers had devoted themselves in the understanding of
icing physics and contributed to the design of different anti-icing strategies. Despite a great
progression in the understanding of icing in recent years, most of the research regarding
freezing are still confined in standard room conditions, with little attention put into the
freezing phenomenon beyond atmospheric environment.
Complex phase change and transport phenomena arise when sessile water droplets are
exposed to low pressure. These intriguing processes have attracted growing interest due to
their fundamental significance in various industries. Here, we report two novel icing
phenomena correlated to the jumping of freezing droplet in low pressure (~ 100 Pa)
environment. These two novel jumping phenomena are driven by different mechanisms,
including the Vaporization Momentum and the Freezing-induced non-condensable gas (NCG)
bubble bursting. The vaporization momentum is contributed by the recalescence induced
vapor flux, while the latter is due to the supersaturation of NCG concentration resulted from
the freezing front propagation. Our findings on these two phenomena provide new insights
into the phase change of supercooled water droplets in reduced pressure conditions, which
will facilitate the design of environment-controlled water-surface interaction systems for coating, cooling, vacuum-freezing, flash distillation, aerospace and deep space exploration-related applications.
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