ie9b06094_si_004.mp4 (3.8 MB)
Significance of Chemical Engineering in Surface Wettability Tuning and Its Boiling Hydrodynamics: A Boiling Heat Transfer Study
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posted on 2020-02-28, 16:37 authored by Jothi Prakash Chakrapani Gunarasan, Prasanth RavindranExperimental
studies are shown to have higher enhancement in critical
heat flux (CHF) with a nanoporous surface. Understanding the mechanism
of CHF is the key to enhance heat transfer through boiling. In general,
the classical theories account some aspects of surface, liquid, and
interfacial properties and boiling phenomena. In this study, the experimental
observations on pool boiling heat transfer are compared with the standard
theoretical models. The porous nanotube surface enabled capillary
wicking (wicking length, ∼0.4 mm) that induced faster dry-spot
rewetting. The post-treatment of the nanotube surface with stearic
acid resulted with hydrophobicity due to alkyl chain adherence to
the nanotube pores. The loss of superhydrophilicity increases thermal
resistance for pool boiling. Hence, the nanoporous superhydrophilic
surface enabled a higher CHF (119 W/cm2) of 36% than that
of the low-surface-energy hydrophobic surface (91 W/cm2). The experimental results observed here follow the trend of the
Liaw and Dhir model accounting surface wettability as the governing
factor.