In the present paper, closed form solutions for the Nusselt number are obtained for hydrodynamically and thermally fully developed combined electroosmotic and pressure-driven flows in narrow confinements for the constant wall heat flux boundary condition. Overcoming the constraints of the standard models that are valid only within thin electrical double layer (EDL) limits, the effects of thick electric double layers are accounted for as a distinctive feature of this model. Along with Joule heating, viscous dissipation effects, which are particularly important for ultrathin channel dimensions (typically conforming to the cases of thick EDLs), are taken into account. The results are presented in terms of appropriate nondimensional parameters depicting the relative EDL thickness with respect to the channel height, as well as relative strengths of Joule heating and viscous dissipation effects.

1.
Maynes
,
D.
, and
Webb
,
B. W.
, 2003, “
Fully Developed Electro-Osmotic Heat Transfer in Microchannels
,”
Int. J. Heat Mass Transfer
0017-9310,
46
, pp.
1359
1369
.
2.
Maynes
,
D.
, and
Webb
,
B. W.
, 2003, “
Fully Developed Thermal Transport in Combined Pressure and Electro-Osmotically Driven Flow in Microchannels
,”
ASME J. Heat Transfer
0022-1481,
125
, pp.
889
895
.
3.
Maynes
,
D.
, and
Webb
,
B. W.
, 2004, “
The Effect of Viscous Dissipation in Thermally Fully Developed Electro-Osmotic Heat Transfer in Microchannels
,”
Int. J. Heat Mass Transfer
0017-9310,
47
, pp.
987
999
.
4.
Chakraborty
,
S.
, 2006, “
Analytical Solutions of Nusselt Number for Thermally Fully Developed Flow in Microtubes Under a Combined Action of Electroosmotic Forces and Imposed Pressure Gradients
,”
Int. J. Heat Mass Transfer
0017-9310,
49
, pp.
810
813
.
5.
Zade
,
A. Q.
,
Manzari
,
M. T.
, and
Hannani
,
S. K.
, 2007, “
An Analytical Solution for Thermally Fully Developed Combined Pressure-Electroosmotically Driven Flow in Microchannels
,”
Int. J. Heat Mass Transfer
0017-9310,
50
, pp.
1087
1096
.
6.
Jain
,
A.
, and
Jensen
,
M. K.
, 2007, “
Analytical Modeling of Electrokinetic Effects on Flow and Heat Transfer in Microchannels
,”
Int. J. Heat Mass Transfer
0017-9310,
50
, pp.
5161
5167
.
7.
Chen
,
C. -H.
, 2009, “
Thermal Transport Characteristics of Mixed Pressure and Electro-Osmotically Driven Flow in Micro- and Nanochannels With Joule Heating
,”
ASME J. Heat Transfer
0022-1481,
131
, pp.
022401
.
8.
Sharma
,
A.
, and
Chakraborty
,
S.
, 2008, “
Semi-Analytical Solution of the Extended Graetz Problem for Combined Electroosmotically and Pressure-Driven Microchannel Flows With Step-Change in Wall Temperature
,”
Int. J. Heat Mass Transfer
0017-9310,
51
, pp.
4875
4885
.
9.
Kirby
,
B. J.
, and
Hasselbrink
,
E. F.
, Jr.
, 2004, “
Zeta Potential of Microfluidic Substrates: 2. Data for Polymers
,”
Electrophoresis
0173-0835,
25
, pp.
203
213
.
10.
Karniadakis
,
G.
,
Beskok
,
A.
, and
Aluru
,
N.
, 2005,
Microflows and Nanoflows: Fundamentals and Simulation
,
Springer Science Business Media, Inc.
,
New York
.
11.
Probstein
,
R. F.
, 1994,
Physicochemical Hydrodynamics: An Introduction
,
2nd ed.
,
Wiley
,
New York
.
12.
Bejan
,
A.
, 2004,
Convective Heat Transfer
,
3rd ed.
,
Wiley
,
New York
.
This content is only available via PDF.
You do not currently have access to this content.