Hydraulic entrance length, X f,h
Velocity
X f,h
X f,t
X f,h
= 0.05Re D
D Lam
X f,h
≅ 20 +
D Turb
Thermal entrance length, X f,t
Prandtl
X f,t
= 0.05Re D Pr
D Lam
168
Analytical Heat Transfer
x
r
R
max
U
Developing flow
Fully developed flow
Re D
τ w
x
0
FIGURE 8.1
Velocity profile and shear stress distribution in a circular tube or between two parallel plates.
FIGURE 8.2
Hydraulic entrance length and thermal entrance length in a circular tube or between two parallel
plates.
Velocity
X f,h
X f,t
X f,h
= 0.05Re D
D Lam
X f,h
≅ 20 +
D Turb
Thermal entrance length, X f,t
Prandtl
X f,t
= 0.05Re D Pr
D Lam
168
Analytical Heat Transfer
x
r
R
max
U
Developing flow
Fully developed flow
Re D
τ w
x
0
FIGURE 8.1
Velocity profile and shear stress distribution in a circular tube or between two parallel plates.
FIGURE 8.2
Hydraulic entrance length and thermal entrance length in a circular tube or between two parallel
plates.