Energy harvesting from thermal energy
has been widely exploited
to achieve energy savings and clean technologies. In this research,
a new cost-effective and environment-friendly solution is proposed
for the growing individual energy needs thanks to the energy application
of cavitating flows. With the aid of cavitating jet flows from microchannel
configurations of different sizes, it is shown that significant temperature
rise (as high as 5.7 °C) can be obtained on the surface of the
thin plate. The obtained heat energy could be integrated to a thermoelectric
power generator, which can be used as a power resource for consumer
devices, such as cell phones and laptops. To explore the difference
in the temperature rise with different microtube diameters, namely,
152, 256, 504, and 762 μm, and also with different upstream
pressures of 10, 20, 40, and 60 bar, the cavitation flow patterns
are captured and analyzed using an advanced high-speed visualization
system. The analysis of the captured data showed that different flow
patterns exist for different diameters of the microtubes, including
a pattern shift from micro- to macroscale, which accompanied the pattern
of temporal results very well.
Boiling
is an efficient heat-transfer mechanism because of the
utilization of latent heat of vaporization and has the potential to
be used for cooling high-power electronic devices. Surface enhancement
is one of the widely used techniques for heat-transfer augmentation
in boiling systems. Here, an experimental investigation was conducted
on chemical vapor deposition-grown three-dimensional (3D) foamlike
graphene-coated silicon surfaces to investigate the effect of pore
structures on pool boiling heat transfer and corresponding heat-transfer
enhancement mechanisms. 3D graphene-coated samples with four graphene
thicknesses were utilized along with a plain surface to investigate
boiling heat-transfer characteristics and enhancement mechanisms.
A high-speed camera was used to provide a deeper understanding of
the bubble dynamics upon departure of emerging bubbles and visualize
vapor columns in different boiling regimes. On the basis of the obtained
results, in addition to interfacial evaporation, mechanical resonance
of the 3D structure had also a considerable effect on vapor column
formation. The results indicated that there is an optimum thickness,
which exhibits the best performance in terms of boiling heat transfer.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.