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Volume 5, Issue 6 (Suppl) J Mat. Sci.
ISSN: 2321-6212 Advanced Materials 2017
October 26-28, 2017
OCTOBER 26-28, 2017 OSAKA, JAPAN
13TH INTERNATIONAL CONFERENCE ON
Advanced Materials and Nanotechnology
Smart materials for energy harvesting and thermal management: Adaptive control and self-driven
devices for heat transfer
Yuyan Jiang1, 2, Chaohong Guo1, 2 and Tao Wang1, 2
1Institute of Engineering Thermophysics-Chinese Academy of Sciences, China
2University of Chinese Academy of Sciences, China
S mart materials, that can change structures and/or physical-chemical properties by active or passive control, has potential
applications in energy engineering. They can be used to design cute and efficient energy converting systems, e.g., waste
heat generation systems made of Shape-Memory-Alloys (SMA). The advances of electronic and aerospace engineering calls
for more robust thermal management technologies that can help the devices to discharge intensive heat release and mitigate
the temperature fluctuation. To this end, smart materials can take their inherent advantages in heat transfer enhancing and in
providing extra measures for driving coolant flow. In our latest studies, a novel deformable structured surface was fabricated
by SMA for the enhancement of boiling heat transfer. Pool boiling heat transfer on deformable structures were performed in
three fluids (ethanol, FC-72, water) with different thermal properties was explored. Comparing heat flux versus wall superheat
and HTC at different fluxes with fixed geometry, it is found that deformable structure combines the merits of closed-tunnel
and open-tunnel. At low heat fluxes, it can increase the numbers of nucleation sites inside the closed tunnels with bent fins
and after recovering with open tunnels, the nucleation sites are activated and the bubble growth and departure is accelerated
to enhance the HTC significantly. On the other hand, by choosing the appropriate time and opportunity for different fluid to
open the tunnels, the deformable structures can be used to achieve adaptive-control of boiling heat transfer. In another study,
researchers from POSTECH proposed a smart TiO2-Coated Surface (TCS) for boiling heat transfer. The surface changes its
wettability with temperature. Measurement of the contact angle of a water droplet on the tested surfaces after heat treatment
showed a wettability increase of TCS, a contact angle reduction from 83.1o to 32.7o when the heat treatment temperature
changed from 100oC to 200oC, in other words, TCS is hydrophobic at a low wall temperature and becomes hydrophilic as
the wall temperature increases. Hydrophobicity of TCS at low wall temperatures. The TCS improved both the heat transfer
coefficient near the boiling inception point at low heat flux regime and critical heat flux at high wall temperatures. People
are also developing heat transfer devices that have SMA self-driven unit for flow circulations that working with temperature
differences. The study on energy harvesting and thermal management by use of smart materials is a quite young interdiscipline
research field, which is still in the initial stage. This presentation gives a critical review to the latest pioneering work. By
summarizing the advancements, we propose some comments on the principles and prospect for the future development.
Biography
Yuyan Jiang is a Professor in the Institute of Engineering Thermophysics (IET), Chinese Academy of Sciences (CAS). He has received BE degree from Xi'an
Jiaotong University (1996), ME degree from Tsinghua University (1999) and PhD from the University of Tokyo (2002). He has been a Post-doctoral Researcher in
IIS, the University of Tokyo (2002-2005), a Senior Research Fellow in AdvanceSoft Inc. (2005-2008) and a Visiting Researcher in Toyota Central R&D Labs Inc.
(2008-2011). He has also been working with CD-Adapco as a Senior Software Engineer. His research interests include the boiling heat transfer, computations of
two-phase flows with phase change. He is one of the major developers of the general-purpose CFD code, FrontFlow/Red. He has published more than 70 peer
reviewed journal papers and has 30 disclosed patents.
Yuyan Jiang et al., J Mat. Sci. 2017, 5:6
DOI: 10.4172/2321-6212-C1-008