Theoretical prediction of the onset of thermal instability in the thermal entrance region of horizontal rectangular channels

Analytical Solution to the Problem of Convective Heat Transfer in a Porous Rectangular Channel for Thermal Boundary Conditions of the Second Genus

“…An analysis of the obtained relation for calculating the length of the initial segment shows that the length is directly proportional to Re and for ε → 1, Da → ∞ coincides with the data of [27].…”

“…The calculations of the local Nusselt number for a porous heat exchanger according to the formula (26) with taking into account the ratio (27) and (28) prove (Fig. 5) that together with the increase of the porosity its meaning decreases with simultenuous decrease of the heat initial section because of the deceleration of the heat carrier in the matrix of the skeleton.…”

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

“…They assumed constant heat flux at the walls with different aspect ratios and showed that the secondary velocity induced due to buoyancy force significantly enhances the heat transfer process and reduces the thermal entrance length. Without the restriction of large Prandtl number, there are detailed numerical studies of mixed convective heat transfer in the entrance region of a horizontal rectangular channel by Abou-Ellai and Morcos [24], Incropera and Schutt [25], Mahaney et al [26], Lin and Chou [27] and Lin et al [28].…”

“…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].…”

Onset of secondary flow and enhancement of heat transfer in horizontal convergent and divergent channels heated from below

“…It is found that as the critical Rayleigh number increases or the Reynolds number decreases, the onset of instability moves upstream. Theoretical analysis [14][15][16] were also performed to predict the onset of the thermal instability. The predictions are close to the experimental [8,9], but were not reported in the experiments with air [2,6].…”