Ks to Clelia Isca for the useful recommendations for the drafting of this text. Conflicts of Interest: The author has no conflict of interest to declare.
applied sciencesArticleDropwise condensation Mechanism on Smooth Hydrophilic SurfacesShahab Bayani Ahangar 1 , Kyung-Bon Lee 2, and Chang Kyoung Choi 1, Department of Mechanical Engineering-Engineering Mechanics, Michigan Technological University, Houghton, MI 49931, USA; [email protected] Division of Biology Education, College of Education, Chonnam National University, Bromfenac Technical Information Gwangju 61186, Korea Correspondence: [email protected] (K.-B.L.); [email protected] (C.K.C.)Featured Application: This operate shows ultra-thin film measurements utilizing surface plasmon resonance imaging (SPRi), which can assist allow a much better understanding on the mechanism of dropwise condensation. Abstract: The objective of this perform is to recognize the mechanism of dropwise condensation on a smooth solid surface. We investigate the steady dropwise condensation that happens at a droplet growth price of 1 /s in diameter on a gold-coated glass surface. Additionally, we present our observations on unstable dropwise condensation, i.e., degradation of dropwise condensation of steam on a gold surface. Surface Plasmon Resonance Imaging (SPRi) is used to evaluate the existence and structure of thin films and occurrence of initial nuclei throughout condensation. SPRi method applied in this study has lateral resolutions of 40 , thickness resolutions of 0.1 nm, and temporal resolutions of 2000,000 frames per second (FPS). Visualization on the onset of steady dropwise condensation suggests droplets type at heterogeneous nucleation internet sites and that no film higher than a monolayer exists on the surface just before the formation of droplets. Observation in the unstable dropwise condensation of steam shows the existence of water films which might be several nanometers thick involving droplets. This perform shows that neither the nucleation theory nor film rupture theory can individually clarify the physics of dropwise condensation. Consequently, there’s a will need for any far more comprehensive theory that will explain the mechanism of dropwise condensation. Keywords and phrases: surface plasmon resonance; thin film; dropwise condensation; monolayer; dropwise condensation mechanism; nucleation; film rupture theory; degradation of dropwise condensationCitation: Bayani Ahangar, S.; Lee, K.-B.; Choi, C.K. Dropwise Condensation Mechanism on Smooth Hydrophilic Surfaces. Appl. Sci. 2021, 11, 9184. https://doi.org/10.3390/ app11199184 Academic Editor: Agnese Magnani Received: 25 August 2021 Accepted: 28 September 2021 Published: two October1. Introduction Dropwise condensation has the prospective to improve efficiency and decrease upkeep costs of heat transfer systems. However, efforts to style and fabricate surfaces to sustain long-term dropwise condensation have not been productive [1,2]. The primary explanation for this lack of success is the fact that the physics behind dropwise condensation is just not fully understood [3]. Presently, you will discover two competing theories on the mechanism of dropwise condensation, particularly, the classical nucleation and film rupture theories [4]. Nucleation theory, 1st introduced by Tammann and Boehme in 1935 [5], claims that droplets nucleate heterogeneously on a surface. Then, the droplets develop and coalesce to make bigger droplets. Heat transfer is dominant by way of the droplets (defined because the active region) along with the location among the droplets is thought of inactive. Umur and Griffith.