
235Heat and Mass Transfer in Fuel Cells
where index i represents the anode and cathode gas stream. The velocity com-
ponents u, v, and w are given by the solution of the Navier-Stokes equation.
6.2.3.2 Electrode–Gas Diffusion Layer
For the porous electrode–gas diffusion layer, the heat equation involves pri-
marily heat generation caused by ohmic heating and heat transfer by con-
duction and convection. The heat equation is expressed as
ρυ
ip
i
i
c
T
t
u
T
x
T
y
w
T
z
x
k
T
x
∂
∂
+
∂
∂
+
∂
∂
+
∂
∂
=
∂
∂
∂
∂
+
∂
∂
∂
∂
+
∂
∂
∂
∂
+
x
k
T
xx
k
T
x
Q
i
,
(6.49)
where index i represents the anode and cathode electrode–gas diffusion
layer. The velocity components u, v, and w are ...