ISSN Online: 2688-7231
ISBN Online: 978-1-56700-524-0
Proceedings of the 26thNational and 4th International ISHMT-ASTFE Heat and Mass Transfer Conference December 17-20, 2021, IIT Madras, Chennai-600036, Tamil Nadu, India
Mathematical Modeling of Dropwise Condensation of Pure Vapor on a Horizontal Tube
A mathematical model is developed to depict the real-time dropwise condensation cycle of saturated vapor on a horizontal textured copper tube. A single droplet heat transfer model is established by including all thermal resistances, namely interfacial, curvature, conduction, and coating layer resistance, in a series network. The tube curvature effect is incorporated in the calculation of the drop volume, conduction inside drop and critical drop size calculations. The gravitational instabilities that lead to the sweeping and falling of droplets from the substrate are analyzed by balancing the forces of surface tension, gravity and internal pressure. The vapor is saturated at a pressure of 0.1 MPa with tube wall temperature selected for degrees of sub-cooling of 1, 3, and 5 K, respectively. For the heat transfer calculations, three coating layer thicknesses of 1, 5, and 10 µm are parametrically analyzed. The intrinsic contact angle of water on a copper tube of diameter 20 mm is 120°. The predictions of the model developed in the present study are seen to be in good agreement with the literature.