Effect of hydrophobicity on enhancement of condensation heat transfer-numerical investigation

In this work, a numerical study has been performed to investigate the effect of surface wettability on the condensation process at different subcooled temperatures using Computational Fluid Dynamics (CFD) simulation in Ansys Fluent. A new CFD model is developed to simulate vapour condensation on vertical smooth surface and surfaces with different hydrophobic coatings in terms of contact angle. Results revealed that the enhancement in condensation heat transfer in terms of heat flux for hydrophobic coatings with contact angle 140° and 150° are about 3 and 2 times, respectively, compared with the plain surface (90°), while less enhancement was achieved for others contact angles. In addition, the highest value of the liquid volume fraction is achieved when hydrophobic coating with contact angle 140° is used.