Moist Air Flow Analysis in an Open Enclosure. Part A: Parametric Study

Heat and mass transfer in many systems is widely accomplished by applying natural convection processes due to their low cost, reliability, and easy support. Typical applications include different mechanisms in various fields such as solar energy, solar distillers, stream cooling, etc. This paper examines the turbulent natural convection and mass transfer in an open enclosure for different Aspect Ratios (AR = 0.5, 1, and 2) with humid air. Mass fraction and local Nusselt number were examined to investigate the heat and mass transfer. Heat flux boundary conditions were subjected to the lateral walls, the bottom one was an adiabatic wall while the top area was a free surface. The effects of Rayleigh numbers (106 <= Ra <= 108) on natural convection and mass flow behavior were analyzed. The governing equations were solved using the CFD Fluent code based on the SIMPLE algorithm. Results showed that a cavity with an aspect ratio of AR=2 enhanced the rates of both heat and mass transfer. Maximum heat transfer rates were observed when the Rayleigh number increased due to the more vigorous fluid flow. However, mass transfer improved when the Rayleigh number decreased.