Convective instability of heat and mass transfer for laminar forced convection in the thermal entrance region of horizontal rectangular channels

Combined heat and mass transfer for laminar flow of moist air in a 3D rectangular duct: CFD simulation and validation with experimental data

“…This will verify the CFD model and experimental data. Contrary to the previous numerical work of Lin and Tzeng [21] which is the closest to the experimental test configuration of [23], a cold water surface is assumed to represent the bottom boundary of the rectangular enclosure in this paper instead of a hot water film as in [21]. In addition, the modeling of boundary condition at the water surface is done in a different way in this work.…”

“…A uniform temperature and uniform concentration was assumed at the bottom wall whereas other walls were kept at zero heat or mass flux. To investigate the onset of convective instability, similar studies were carried out by Lin and Tzeng [21] for flow of humid air in a 3D rectangular duct. They performed a numerical study considering buoyancy forces due to temperature and concentration gradients and latent heat transfer due to the vaporization of a liquid-water film.…”

“…In addition, the modeling of boundary condition at the water surface is done in a different way in this work. Instead of a constant temperature and concentration boundary condition [20,21], temperature and concentration at the water surface is calculated based on the fact that latent heat of evaporation is equal to the sensible heat transfer from air to water. In addition, heat and mass transfer analogy is defined with a new non-dimensionless parameter.…”

“…There are a lot of research works on the determination of heat and mass transfer coefficients considering the effect of buoyancy forces and a large share of it belongs to the internal flows . Whereas some of the works consider only heat transfer [9][10][11][12][13][14][15][24][25][26][27][28] to quantify Nusselt number, many of them treat simultaneous heat and mass transfer [16][17][18][19][20][21][22][23]29,30] to determine Nusselt and Sherwood numbers together. Most of the works in the literature present numerical data and correlations [9][10][11][12][13][16][17][18][19][20][21][22][24][25][26][27][28]30] with only a few presenting experimental data and correlations [14,15,23,29].…”

Mixed Convection Heat and Mass Transfer with Phase Change and Flow Reversal in Channels

“…Their results show that large film evaporation rates are obtained for larger tube wall temperature. Convective instability of heat and mass transfer for laminar forced convection in the thermal entrance region of a horizontal rectangular channel has been examined by Lin et al (1992). The rectangular channel is thermally insulated except for the bottom wall.…”