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10
Forced Convection Heat
Transfer: External Flows
10.1 NORMALIZED BOUNDARY LAYER EQUATIONS
Conservation equations have been derived for physical variables such as velocity
components, pressure, and temperature. However, a lot can be learned about the
solution of these equations if those variables are normalized. Consider the two-
dimensional, steady-state boundary layer equations [1]:
(10.1)
U
U
x
V
U
y
P
x
U
y
X∂
∂
+
∂
∂
=−
∂
∂
+
∂
∂
+
1
ρ
ν
ρ
2
2
,
(10.2)
(10.3)
U
T
x
V
T
y
T
yC
U
y
g
C
pp
∂
∂
+
∂
∂
=
∂
∂
+
∂
∂
+α
ν
ρ
2
2
2
.
(10.4)
If L is a characteristic length of the ow, the normalized coordinates will be
dened a ...