This article investigates the influence of diffusion-thermo effect on transient free convective heat and mass transfer flow in a channel bounded by two infinite vertical parallel plates. Fully developed laminar flow is considered when the boundaries are subjected to symmetric concentration and thermal input. The Dufour effect is taken into consideration. The velocity, temperature, and concentration profiles are obtained analytically using the Laplace transforms technique and used to compute the shear stress, Nusselt number, and mass flux. During the course of computation, it was found that transient solution at large time coincides with steady-state solution derived separately. Diffusion-thermo (Dufour effect) is observed to create an anomalous situation in temperature and velocity profiles for small Prandtl numbers. There is also flow reversal for a small Dufour number and negative values of the sustentation parameter (N). At steady-state, there is neither heat nor mass transfer between the fluid and the plates.

1.
Gebhart
,
B.
, and
Pera
,
L.
, 1971, “
The Nature of Vertical Natural Convection Flows Resulting From the Combined Buoyancy Effects of Thermal and Mass Diffusion
,”
Int. J. Heat Mass Transfer
0017-9310,
14
, pp.
2025
2050
.
2.
Soundalgekar
,
V. M.
, 1979, “
Effects of Mass Transfer and Free Convection Currents on the Flow Past an Impulsively Started Vertical Plate
,”
ASME J. Appl. Mech.
0021-8936,
46
, pp.
757
760
.
3.
Kafoussias
,
N. G.
, and
Williams
,
E. W.
, 1995, “
Thermal-Diffusion and Diffusion-Thermo Effects on Mixed Free-Forced Convective and Mass Transfer Boundary Layer Flow With Temperature Dependent Viscosity
,”
Int. J. Eng. Sci.
0020-7225,
33
(
9
), pp.
1369
1384
.
4.
Alam
,
M. S.
,
Rahman
,
M. M.
,
Ferdows
,
M.
,
Kaino
,
K.
,
Mureithi
,
E.
, and
Postelnicu
,
A.
, 2007, “
Diffusion-Thermo and Thermal-Diffusion Effects on Free Convective Heat and Mass Transfer Flow in a Porous Medium With Time Dependent Temperature and Concentration
,”
Int. J. Appl. Eng. Res.
,
2
(
1
), pp.
81
96
.
5.
Eckert
,
E. R. G.
, and
Drake
,
R. M.
, 1972,
Analysis of Heat and Mass Transfer
,
McGraw-Hill
,
New York
.
6.
Soundalgekar
,
V. M.
, and
Akolkar
,
S. P.
, 1983, “
Effects of Free Convective Currents and Mass Transfer Flow Past a Vertical Oscillating Plate
,”
Astrophys. Space Sci.
0004-640X,
89
, pp.
241
254
.
7.
Jha
,
B. K.
, and
Singh
,
A. K.
, 1990, “
Soret Effects on Free Convection and Mass Transfer Flow in the Stokes Problem for an Infinite Vertical Plate
,”
Astrophys. Space Sci.
0004-640X,
173
, pp.
251
255
.
8.
Jha
,
B. K.
, 1992, “
Unsteady Mixed Convection Flow With Thermal-Diffusion Effect
,”
Astrophys. Space Sci.
0004-640X,
191
, pp.
283
288
.
9.
Jha
,
B. K.
, 1994, “
Soret Effects on Free Convection and Mass Transfer Flow With Constant Heat Flux
,”
Modelling, Measurement and Control
,
ASME
,
New York
, Vol.
46
, pp.
55
64
.
10.
Soundalgekar
,
V. M.
,
Lahurikar
,
R. M.
, and
Pohanerkar
,
S. G.
, 1993, “
Mass Transfer Effects on the Unsteady Forced and Free Convective Flow Through a Porous Medium Past an Infinite Vertical Isothermal Plate
,”
ASME J. Heat Transfer
0022-1481,
115
, pp.
276
278
.
11.
Dursunkaya
,
Z.
, and
Worek
,
M. W.
, 1992, “
Diffusion-Thermo and Thermal-Diffusion Effects in Transient and Steady Natural Convection From a Vertical Surface
,”
Int. J. Heat Mass Transfer
0017-9310,
35
(
8
), pp.
2060
2065
.
12.
Alam
,
M. S.
,
Rahman
,
M. M.
, and
Samad
,
M. A.
, 2006, “
Dufour and Soret Effects on Unsteady MHD Free Convection and Mass Transfer Flow Past a Vertical Porous Plate in a Porous Medium
,”
Nonlinear Analysis: Modelling and Control
1392-5113,
11
(
3
), pp.
217
226
.
13.
Beg
,
O. A.
,
Beg
,
T. A.
,
Bakier
,
A. Y.
, and
Prasad
,
V. R.
, 2009, “
Chemically-Reacting Mixed Convective Heat and Mass Transfer Along Inclined and Vertical Plates With Soret and Dufour Effects: Numerical Solutions
,”
Int. J. Appl. Math. Mech.
0973-0184,
5
(
2
), pp.
39
57
.
14.
Lee
,
K. T.
, and
Yan
,
W. M.
, 1994, “
Laminar Natural Convection Between Partially Heated Vertical Parallel Plates
,”
Warme-und Stoffubertragung
,
29
, pp.
145
151
.
15.
Hajji
,
A.
, and
Worek
,
W. M.
, 1988, “
Analysis of Combined Fully-Developed Natural Convection Heat and Mass Transfer Between Two Inclined Parallel Plates
,”
Int. J. Heat Mass Transfer
0017-9310,
31
(
9
), pp.
1933
1940
.
16.
Nelson
,
D. J.
, and
Wood
,
B. D.
, 1989, “
Fully Developed Combined Heat and Mass Transfer Natural Convection Between Parallel Plates With Asymmetric Boundary Conditions
,”
Int. J. Heat Mass Transfer
0017-9310,
32
(
9
), pp.
1789
1792
.
17.
Singh
,
A. K.
, and
Paul
,
T.
, 2006, “
Transient Natural Convection Between Two Vertical Walls Heated/Cooled Asymmetrically
,”
Appl. Mech. Eng.
1425-1655,
11
(
1
), pp.
143
154
.
18.
Jha
,
B. K.
, 2001, “
Transient Free-Convective Flow in a Vertical Channel With Heat Sinks
,”
Appl. Mech. Eng.
1425-1655,
6
(
2
), pp.
279
286
.
19.
Jha
,
B. K.
,
Singh
,
A. K.
, and
Takhar
,
H. S.
, 2003, “
Transient free-convective flow in a vertical channel due to symmetric heating
,”
Appl. Mech. Eng.
1425-1655,
8
(
3
), pp.
497
502
.
20.
Churchill
,
R. V.
, 1972,
Operational Mathematics
,
3rd ed.
, International Student Edition,
McGraw-Hill
,
New York
, pp.
458
476
.
21.
Abramowitz
,
M.
and
Stegun
,
I. A.
, eds., 1965,
Handbook of Mathematical functions, With formulas, Graphs and Mathematical Tables
,
Dover
,
New York
.
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