{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,1]],"date-time":"2026-01-01T10:04:48Z","timestamp":1767261888527,"version":"build-2065373602"},"reference-count":38,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2021,5,2]],"date-time":"2021-05-02T00:00:00Z","timestamp":1619913600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Symmetry"],"abstract":"<jats:p>In this paper the mathematical and physical correlation between fundamental thermophysical properties of materials, with their structure, for nanofluid thermal performance in spray cooling applications is presented. The present work aims at clarifying the nanofluid characteristics, especially the geometry of their nanoparticles, leading to heat transfer enhancement at low particle concentration. The base fluid considered is distilled water with the surfactant cetyltrimethylammonium bromide (CTAB). Alumina and silver are used as nanoparticles. A systematic analysis addresses the effect of nanoparticles concentration and shape in spray hydrodynamics and heat transfer. Spray dynamics is mainly characterized using phase Doppler interferometry. Then, an extensive processing procedure is performed to thermal and spacetime symmetry images obtained with a high-speed thermographic camera to analyze the spray impact on a heated, smooth stainless-steel foil. There is some effect on the nanoparticles\u2019 shape, which is nevertheless minor when compared to the effect of the nanoparticles concentration and to the change in the fluid properties caused by the addition of the surfactant. Hence, increasing the nanoparticles concentration results in lower surface temperatures and high removed heat fluxes. In terms of the effect of the resulting thermophysical properties, increasing the nanofluids concentration resulted in the increase in the thermal conductivity and dynamic viscosity of the nanofluids, which in turn led to a decrease in the heat transfer coefficients. On the other hand, nanofluids specific heat capacity is increased which correlates positively with the spray cooling capacity. The analysis of the parameters that determine the structure, evolution, physics and both spatial and temporal symmetry of the spray is interesting and fundamental to shed light to the fact that only knowledge based in experimental data can guarantee a correct setting of the model numbers.<\/jats:p>","DOI":"10.3390\/sym13050788","type":"journal-article","created":{"date-parts":[[2021,5,2]],"date-time":"2021-05-02T08:05:21Z","timestamp":1619942721000},"page":"788","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":23,"title":["Nanofluids Characterization for Spray Cooling Applications"],"prefix":"10.3390","volume":"13","author":[{"given":"Miguel","family":"Sanches","sequence":"first","affiliation":[{"name":"IN+ Center for Innovation, Technology and Policy Research, Instituto Superior T\u00e9cnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal"}]},{"given":"Guido","family":"Marseglia","sequence":"additional","affiliation":[{"name":"Escuela T\u00e9cnica Superior de Arquitectura de Sevilla, Av. de la Reina Mercedes, 2, 41012 Seville, Spain"},{"name":"Instituto de Matem\u00e1ticas de la Universidad de Sevilla, (IMUS), Universidad de Sevilla, 41012 Seville, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4323-4328","authenticated-orcid":false,"given":"Ana P. C.","family":"Ribeiro","sequence":"additional","affiliation":[{"name":"Centro de Qu\u00edmica Estrutural, Instituto Superior T\u00e9cnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5333-5056","authenticated-orcid":false,"given":"Ant\u00f3nio L. N.","family":"Moreira","sequence":"additional","affiliation":[{"name":"IN+ Center for Innovation, Technology and Policy Research, Instituto Superior T\u00e9cnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9801-7617","authenticated-orcid":false,"given":"Ana S.","family":"Moita","sequence":"additional","affiliation":[{"name":"IN+ Center for Innovation, Technology and Policy Research, Instituto Superior T\u00e9cnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal"},{"name":"CINAMIL\u2014Military Academy Research Center, Portuguese Military Academy, 1169-203 Lisbon, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2021,5,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"636","DOI":"10.1016\/j.applthermaleng.2016.05.096","article-title":"A review of the capabilities of high heat flux removal by porous materials, microchannels and spray cooling techniques","volume":"112","author":"Smakulski","year":"2016","journal-title":"Appl. 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