In this work we aim to develop a theoretical framework for evaluating the feasibility of attaining significant improvement of fuel cells performance and stability by enhancing the transport processes in porous partially-fluid-filled cathode compartments through applying acoustic and structural excitations. A generic unified model has been derived of the structural/acoustic wave propagation in the porous media with consideration of its coupling with mass transfer. It has been demonstrated that the phase saturation has a strong impact on the wave dynamics in porous media. Explicit expressions have been obtained for the generalized multiphase Biot-type coefficients. A generalized filtration equation has been derived that takes into account the effects on mass transfer of dynamic loading, varying saturation, and solid structure distortion in this complex system. For model calibration a series of tests has been conducted to measure water flows through porous media with and without acoustic excitations. It has been demonstrated that the excitations may result in a net change of the saturation inside the porous medium and the applied structural/acoustic loading can intensify the transportation process. Based on the numerical and experimental results, certain recommendations have been made in regards to the selection of materials and the optimization of performance regime.

1.
K. Kordesch, G. Simader, Fuel Cells and their applications. VCH, 1996, 374 p
2.
Biot
M. A.
,
Theory of Propagation of Elastic Waves in a Fluid Saturated Porous Solid. I. Low Frequency Range. II. Higher Frequency Range
.
The Journal of the Acoustical Society of America
28
(
2
)
168
191
,
1956
3.
J. Allard. Propagation of Sound in Porous Media. Elsever Applied Science, 1993
4.
Gray
W.
and
Hassanizadeh
S.
.
Macroscale continuum mechanics for multiphase porous-media flow including phases, interfaces, common lines and common points
.
Advances in Water Resources
,
21
, pp.
261
281
,
1998
.
5.
S. Nemat_Nasser and M. Hori. Micromechanics: overall properties of heterogeneous materials. Elsevier 1999
6.
L. Molotkov. On tortuosity coefficients in effective Biot model. Notes of scientific seminars of POMI, 257, 1999, pp. 157–163. (In Russian).
7.
L. Landau and E. Lifshitz. Theory of Elasticity. 1987.
8.
Hassanizadeh
S. M.
and
Gray
W. G.
.
Mechanics and thermodynamics of multiphase flow in porous media including interphase boundaries
.
Advanced Water Resources
,
13
, pp.
169
186
.
9.
Beliaev
A.
and
Hassanizadeh
S. M.
.
A Theoretical Model of Hysteresis and Dynamic Effects in the Capillary Relation for Two-phase Flow in Porous Media
.
Transport in Porous Media
,
43
, pp.
487
510
, 2001.
10.
Barenblatt
G. I.
.
Filtration of Two Non-mixing Fluids in a Homogeneous Porous Medium
.
Mechanics of Gas and Fluids
,
5
, pp.
857
864
,
1971
.
11.
O. Coussy, Mechanics of Porous Continua, J. Wiley & Sons, 1995, 455p.
12.
J. Bear. Dynamics of Fluids in Porous Media. Dover Publications, INC. 1988.
13.
Maksimov
A. M.
,
Radkevich
E. V.
and
Edelman
I. Ja.
.
The Mechanism of Nonperiodic Motion in Porous Media as a Result of the Accumulating Effect of Nonlinear Waves
.
Journal of Engineering Physics and Thermophysics
,
70
, pp.
1
8
,
1997
.
14.
A. Lubag and J. Yi Studies on Water Permeation through the Sub-layer. UTCFC report, 2002.
15.
W.L. Nyborg. Acoustic streaming. In: Mason W.P., ed., Physical acoustics, IIB, New York: Academic Press; pp. 265–331, 1965.
16.
Carlstrom Jr., Maynard, W., Fuel Cell with Selective Pressure Variation and Dynamic Inflection, US6093502
This content is only available via PDF.
You do not currently have access to this content.