ISSN Online: 2377-424X
ISBN Print: 978-1-56700-421-2
International Heat Transfer Conference 15
Flow Condensation Heat Transfer on Engineered Surfaces
Resumo
Condensation heat transfer has recently received a lot of renewed attention due to the development and use of
surfaces with micro- and nano-scale features. Most of the new surfaces tend to promote dropwise condensation
which leads to higher rates of heat transfer when compared with filmwise condensation. In the current study, the
effects of surface morphology and surface chemistry on the condensation mechanisms have been investigated
using engineered surfaces. Firstly, hybrid surfaces consisting of an array of micropillars with hydrophobic and
hydrophilic sites and other engineered surfaces have been designed to exhibit a distinct Cassie-Baxter wetting
behavior. Experiments have revealed that a nanoparticles-based hydrophobic surface depicts a unique wetting
behavior which could lead to enhanced dropwise condensation under the right ambient conditions. Experiments
have been conducted to determine the heat transfer performance of hybrid and other engineered surfaces under a
constant humidity level, surface-to-ambient temperature difference, and laminar flow conditions. Results to date
show that condensed droplet dynamics play an important role during the overall condensation process.
Palavras-chave:
Two-phase/Multiphase flow, Convection, Hybrid surfaces, dropwise condensation, hydrophobic, hydrophillic, droplet shedding