Evaporation of Water by Natural Convection in Partially Wetted Heated Vertical Plates: Effect of the Number of the Wetted Zone

This research consists of a numerical investigation of coupled heat and mass transfers by natural convection during water evaporation in a vertical channel. The two channel walls were symmetrically heated by a uniform flux density. One wall is partially wetted by an extremely thin water film and the other is dry. The partially humid plate is divided into 2N with equal lengths being alternatively wet and dry zones. The results are reported in terms of local Sherwood number, the inlet velocity and evaporative rate for different wet zone position and for different wet number zones. However, the mass transfer is extremely influenced by the number of the wetted zones and their positions. The evaporative rate is more intense when the wetted zone is situated at the channel exit. Finally, it is observed that the evaporation is intensified by increasing the number of wetted zones.