20.500.12556/RUL-127676 Pool boiling performance of water and self-rewetting fluids on hybrid functionalized aluminum surfaces The boiling performance of functionalized hybrid aluminum surfaces was experimentally investigated for water and self-rewetting mixtures of water and 1-butanol. Firstly, microstructured surfaces were produced via chemical etching in hydrochloric acid and the effect of the etching time on the surface morphology was evaluated. An etching time of 5 min was found to result in pitting corrosion and produced weakly hydrophilic microstructured surfaces with many microcavities. Observed cavity-mouth diameters between 3.6 and 32 µm are optimal for efficient nucleation and provided a superior boiling performance. Longer etching times of 10 and 15 min resulted in uniform corrosion and produced superhydrophilic surfaces with a micropeak structure, which lacked microcavities for efficient nucleation. In the second stage, hybrid surfaces combining lower surface energy and a modified surface microstructure were created by hydrophobization of etched aluminum surfaces using a silane agent. Hydrophobized surfaces were found to improve boiling heat transfer and their boiling curves exhibited a significantly lower superheat. Significant heat transfer enhancement was observed for hybrid microcavity surfaces with a low surface energy. These surfaces provided an early transition into nucleate boiling and promoted bubble nucleation. For a hydrophobized microcavity surface, heat transfer coefficients of up to 305 kW m$^{−2}$ K$^{−1}$ were recorded and an enhancement of 488% relative to the untreated reference surface was observed. The boiling of self-rewetting fluids on functionalized surfaces was also investigated, but a synergistic effect of developed surfaces and a selfrewetting working fluid was not observed. An improved critical heat flux was only obtained for the untreated surface, while a lower critical heat flux and lower heat transfer coefficients were measured on functionalized surfaces, whose properties were already tailored to promote nucleate boiling. pool boiling nucleate boiling surface modification functionalized surfaces heat transfer enhancement self-rewetting fluids vrenje v bazenu mehurčkasto vrenje površinska modifikacija funkcionalizirane površine izboljšan prenos toplote samoomočljivi fluidi true false true Angleški jezik Slovenski jezik Članek v reviji 2021-06-18 13:57:28 2021-06-18 13:57:29 2023-11-29 09:16:21 0000-00-00 00:00:00 2021 0 0 27 str. iss. 6, art. 1058 Vol. 9 Jun. 2021 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 536.242:66.046.7 2227-9717 10.3390/pr9061058 67560707 RAZ_Moze_Matic_2021.pdf RAZ_Moze_Matic_2021.pdf 1 26FB7A2F8526B3981200B5C02D149D75 f597e1000c4cee8bee3c3d49032972b35bafca920e23be1c360a148fd0bec8b7 8c5cf63d-ab4e-11ec-8aca-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=154890 RAZ_Moze_Matic_2021.pdf RAZ_Moze_Matic_2021.pdf 1 A99ED7AE8C16E37021CACA14392D91F7 ee990d1edfccedf3ab5f7ba0f8317dd7d855cf5eca02d529554e76e1c6cab628 cdd5d702-d02d-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=144157 https://www.mdpi.com/2227-9717/9/6/1058 1 41b9798e-d02c-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=144155 Fakulteta za strojništvo 0 0 0