Effect of wall surface roughness on droplet cooling over a rectangular heated plate in an enclosure

Abstract

Study of evaporation of single droplet plays a very important role in analyzing the process operations of fuel cooling and spraying systems. This has been a pioneering area of research among chemical and heat transfer engineers. In the present work, an experimental and numerical study of the dynamics of droplet evaporation inside a rectangular enclosure is carried out. The width of the enclosure is less than the spreading radius of the droplet which generates two contact angles, one with the heated surface and the other with the enclosure and this makes the study important. The droplet absorbs a considerable amount of heat as it evaporates on the plate thereby reducing its temperature. The introduction of enclosure enhances the cooling effect when compared to droplet cooling in the plate without enclosure. The effect of heat transfer with the introduction of rectangular enclosure is studied based on the numerical analysis. Turbulence modelling is used with standard wall treatment to study the effect of surface roughness on droplet evaporation in the presence of a rectangular enclosure. A change in the dynamics of the droplet with change in surface roughness of the heated plate and wall enclosure is reported in terms of variation in contact angle and heat transfer characteristics.