Enhanced Multiscale Boiling Surfaces (EMBOSS): From Fundamentals to Design

Lead Research Organisation: University of Edinburgh
Department Name: Sch of Engineering


Boiling phenomena are central to heating and cooling duties in many industries, such as cooling and refrigeration, power generation, and chemical manufacture. Limitations to boiling heat transfer arise through surface dry-out at high heat flux, leading to localised hot-spots on heat transfer surfaces and larger equipment requirements. Whilst this is a significant problem for many industries, it becomes even more of an issue when dealing with small-scale systems, such as those used for cooling of microelectronics, where failure to remove heat effectively leads to localised overheating and potential damage of components. Spatially non-uniform and unsteady dissipative heat generation in such systems is detrimental to their performance and longevity. The effective heat exchanger area is of order sq. cm, with heat fluxes of order MW/sqm. This requires a transformative, step-change, beyond the current state-of-the-art for cooling heat fluxes between 2-15 MW/sqm at local "hot spots" to prevent burn out.
A number of attempts have already been made to extend the upper boundary for the heat flux through alteration of surface characteristics with the aim of improved nucleation of vapour bubbles, bubble detachment, and subsequent rewetting of the surface by liquid. Despite the progress made, previous work on surfaces for pool- (and potentially flow-) boiling does not involve a rational approach for developing optimal surface topography. For instance, nucleate boiling heat transfer (NBHT) decreases with increasing wettability, and the designer must consider the nucleation site density, associated bubble departure diameter, and frequency related to the surface structure and fluid phase behaviour. For high surface wettability, the smaller-scale surface structure characteristics (e.g. cavities) can act as nucleation sites; for low wettability, the cavity dimensions, rather than its topology, will dominate. Therefore, characterising surfaces in terms of roughness values is insufficient to account for the changes in the boiling curve: the fluid-surface coupling must be studied in detail for the enhancement of NBHT and the critical heat flux.
EMBOSS brings together a multi-disciplinary team of researchers from Brunel, Edinburgh, and Imperial, and six industrial partners and a collaborator (Aavid Thermacore, TMD ltd, Oxford Nanosystems, Intrinsiq Materials, Alfa Laval, CALGAVIN, and OxfordLasers) with expertise in cutting-edge micro-fabrication, experimental techniques, and molecular-, meso- and continuum-scale modelling and simulation. The EMBOSS framework will inform the rational design, fabrication, and optimisation of operational prototypes of a pool-boiling thermal management system. Design optimality will be measured in terms of materials and energy savings, heat-exchange equipment efficiency and footprint, reduction of emissions, and process sustainability. The collaboration with our partners will ensure alignment with the industrial needs, and will accelerate technology transfer to industry. These partners will provide guidance and advice through the project progress meetings, which some of them will also host. In addition, Alfa Laval will provide brazed heat exchangers as condensers for the experimental work, Intrinsiq will provide copper ink for coating surfaces and Oxford nanoSystems will provide nano-structured surface coatings. The project will integrate the challenges identified by EPSRC Prosperity Outcomes and the Industrial Strategy Challenge Fund in Energy (Resilient Nation), manufacturing and digital technologies (Resilient Nation, Productive Nation), as areas to drive economic growth.


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Description The project started six months ago. The main key findings are:

-The upgrade of the pool boiling rig and its instrumentation.
- the buildings of the first substrates and boiling test section with artificial cavities.
-The modeling is progressing with coordination with partners at Imperial College.
-Significant data on the effect of wettability and cavities influence on bubbles nucleation, growth and interactions are obtained.
-We anticipate some significant outputs from these data.
Exploitation Route This award is still ongoing and we anticipate to have more of the above in the future.
Sectors Aerospace, Defence and Marine,Chemicals,Electronics

Description Coolboration with teh International Centre for Carbon Neutral Energy Research (I2CNER) at Kyushu University, Japan 
Organisation Kyushu University
Country Japan 
Sector Academic/University 
PI Contribution The collaboration started in 2015 when Profesor K. Sefiane was awarded a Progress100 grant by Kyushu University to support collaboration between the two Universities. The initial grant was for 18 months. Professor Sefiane has been succesful in renewing this grant in 2018 for another 3 years.#The funding provided support to appoint a research assistant at Kyushu University and pay for travel expenses between Edinburgh and Kyushu for staff from the two groups.
Collaborator Contribution Two research awards: 2015-2016 2018-2021 The total amounts of these two awards was about 100,000 £.
Impact J Chen, YH; Askounis, A; Koutsos, V; Valluri, P; Takata, Y; Wilson, SK; Sefiane, K Chen, Yuhong; Askounis, Alexandros; Koutsos, Vasileios; Valluri, Prashant; Takata, Yasuyuki; Wilson, Stephen K.; Sefiane, Khellil On the Effect of Substrate Viscoelasticity on the Evaporation Kinetics and Deposition Patterns of Nanosuspension Drops LANGMUIR 0743-7463 JAN 14 2020 36 1 204 213 10.1021/acs.langmuir.9b02965 WOS:000507721200022 31860312 J Zhang, HC; Kita, Y; Zhang, DJ; Nagayama, G; Takata, Y; Sefiane, K; Askounis, A Zhang, Huacheng; Kita, Yutaku; Zhang, Dejian; Nagayama, Gyoko; Takata, Yasuyuki; Sefiane, Khellil; Askounis, Alexandros Drop Evaporation on Rough Hot-Spots: Effect of Wetting Modes HEAT TRANSFER ENGINEERING Kita, Yutaku/AAC-5533-2020; Askounis, Alexandros/O-9585-2014 Kita, Yutaku/0000-0003-4994-4689; Askounis, Alexandros/0000-0003-0813-7856; , nagayamakit/0000-0002-6836-9387 0145-7632 1521-0537 10.1080/01457632.2019.1640458 AUG 2019 WOS:000480615200001 J Wang, ZY; Orejon, D; Sefiane, K; Takata, Y Wang, Zhenying; Orejon, Daniel; Sefiane, Khellil; Takata, Yasuyuki Coupled thermal transport and mass diffusion during vapor absorption into hygroscopic liquid desiccant droplets INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER Orejon, Daniel/G-4468-2013 Orejon, Daniel/0000-0003-1037-5036; Wang, Zhenying/0000-0002-2651-1808 0017-9310 1879-2189 MAY 2019 134 1014 1023 10.1016/j.ijheatmasstransfer.2019.01.084 WOS:000462418300086 J Wang, ZY; Orejon, D; Sefiane, K; Takata, Y Wang, Zhenying; Orejon, Daniel; Sefiane, Khellil; Takata, Yasuyuki Water vapor uptake into hygroscopic lithium bromide desiccant droplets: mechanisms of droplet growth and spreading PHYSICAL CHEMISTRY CHEMICAL PHYSICS Orejon, Daniel/G-4468-2013 Orejon, Daniel/0000-0003-1037-5036; Wang, Zhenying/0000-0002-2651-1808 1463-9076 1463-9084 JAN 21 2019 21 3 10.1039/c8cp04504f WOS:000456147000073 30320327 J Kita, Y; Dover, CM; Askounis, A; Takata, Y; Sefiane, K Kita, Yutaku; Dover, Coinneach Mackenzie; Askounis, Alexandros; Takata, Yasuyuki; Sefiane, Khellil Drop mobility on superhydrophobic microstructured surfaces with wettability contrasts SOFT MATTER Askounis, Alexandros/O-9585-2014; Kita, Yutaku/AAC-5533-2020 Askounis, Alexandros/0000-0003-0813-7856; Kita, Yutaku/0000-0003-4994-4689 1744-683X 1744-6848 DEC 14 2018 14 46 9418 9424 10.1039/c8sm01762j WOS:000451843300013 30427033 J Kita, Y; Okauchi, Y; Fukatani, Y; Orejon, D; Kohno, M; Takata, Y; Sefiane, K Kita, Yutaku; Okauchi, Yuya; Fukatani, Yuki; Orejon, Daniel; Kohno, Masamichi; Takata, Yasuyuki; Sefiane, Khellil Quantifying vapor transfer into evaporating ethanol drops in a humid atmosphere PHYSICAL CHEMISTRY CHEMICAL PHYSICS Kita, Yutaku/AAC-5533-2020; Orejon, Daniel/G-4468-2013 Kita, Yutaku/0000-0003-4994-4689; Orejon, Daniel/0000-0003-1037-5036 1463-9076 1463-9084 AUG 7 2018 20 29 19430 19440 10.1039/c8cp02521e WOS:000448132600017 29993049 J Tomo, Y; Askounis, A; Ikuta, T; Takata, Y; Sefiane, K; Takahashi, K Tomo, Yoko; Askounis, Alexandros; Ikuta, Tatsuya; Takata, Yasuyuki; Sefiane, Khellil; Takahashi, Koji Superstable Ultrathin Water Film Confined in a Hydrophilized Carbon Nanotube NANO LETTERS Askounis, Alexandros/O-9585-2014 Askounis, Alexandros/0000-0003-0813-7856; Tomo, Yoko/0000-0001-6002-1506 1530-6984 1530-6992 MAR 2018 18 3 1869 1874 10.1021/acs.nanolett.7b05169 WOS:000427910600043 29424547 J Barletta, A; Bejan, A; Briggs, A; Cavallini, A; Cotta, R; Garimella, S; Glicksman, L; Hewitt, G; Karayiannis, T; Manglik, R; Minkowycz, WJ; Sefiane, K; Takata, Y; Thome, J; Utaka, Y; Wang, HS; Yoshida, H Barletta, Antonio; Bejan, Adrian; Briggs, Adrian; Cavallini, Alberto; Cotta, Renato; Garimella, Srinivas; Glicksman, Leon; Hewitt, Geoffrey; Karayiannis, Tassos; Manglik, Raj; Minkowycz, W. J.; Sefiane, Khellil; Takata, Yas; Thome, John; Utaka, Yoshio; Wang, Huasheng; Yoshida, Hideo Professor John W. Rose BScEng PhD DScEng(Lond) CEng FIMechE FASME on his 80th birthday In Celebration INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER Barletta, Antonio/O-8888-2019; Cotta, Renato M/H-5336-2012; Bejan, Adrian/D-3909-2012; Utaka, Yoshio/Q-8596-2019 Cotta, Renato M/0000-0003-0965-0811; Bejan, Adrian/0000-0002-2419-2698; 0017-9310 1879-2189 SEP 2017 112 169 170 10.1016/j.ijheatmasstransfer.2017.04.038 WOS:000404198600016 J Askounis, A; Kita, Y; Kohno, M; Takata, Y; Koutsos, V; Sefiane, K Askounis, Alexandros; Kita, Yutaku; Kohno, Masamichi; Takata, Yasuyuki; Koutsos, Vasileios; Sefiane, Khellil Influence of Local Heating on Marangoni Flows and Evaporation Kinetics of Pure Water Drops LANGMUIR Kita, Yutaku/AAC-5533-2020; Askounis, Alexandros/O-9585-2014; Koutsos, Vasileios/B-9651-2008 Kita, Yutaku/0000-0003-4994-4689; Askounis, Alexandros/0000-0003-0813-7856; Koutsos, Vasileios/0000-0002-2203-8179 0743-7463 JUN 13 2017 33 23 5666 5674 10.1021/acs.langmuir.7b00957 WOS:000403530200008 28510453 J Yamada, Y; Askounis, A; Ikuta, T; Takahashi, K; Takata, Y; Sefiane, K Yamada, Yutaka; Askounis, Alexandros; Ikuta, Tatsuya; Takahashi, Koji; Takata, Yasuyuki; Sefiane, Khellil Thermal conductivity of liquid/carbon nanotube core-shell nanocomposites JOURNAL OF APPLIED PHYSICS Askounis, Alexandros/O-9585-2014 Askounis, Alexandros/0000-0003-0813-7856 0021-8979 1089-7550 JAN 7 2017 121 1 015104 10.1063/1.4973488 WOS:000392839400041
Start Year 2015