
376 Heat Transfer: Thermal Management of Electronics
(14.83)
(14.84)
(14.85)
−=
∂
∂
+
∂
∂
UV
U
x
V
y
t
′′ ν ,
(14.86)
−=
∂
∂
+
∂
∂
UW
U
z
W
z
t
′′ν ,
(14.87)
−=
∂
∂
+
∂
∂
VW
V
z
W
y
t
′′ν ,
(14.88)
where
(14.89)
is the turbulent kinetic energy, and dening turbulent diffusivity, α
t
, or turbulent
Prandtl number, Pr
t
= ν
t
/α
t
, such that
(14.90)
(14.91)
(14.92)
It is seen that the problem of determining turbulent shear stresses and turbulent
heat uxes was reduced to the problem of determining the turbulent ...