Civil Engineering Reference
In-Depth Information
T
1
a
b
c
T
2
x
5
8 in.
2 in.
5
8 in.
(a)
1
2
3
1
4
2
3
(b)
Figure P7.15
7.16
The wall of Problem 7.15 carries a centrally located electrical cable, which is
to be treated as a line heat source of strength
Q
∗
=
constant
,
as shown in
Figure P7.16. With this change, can the problem still be treated as one
dimensional? If your answer is yes, solve the problem using three elements
as in Problem 7.15. If your answer is no, explain.
Q
*
Figure P7.16
7.17
A common situation in polymer processing is depicted in Figure P7.17, which
shows a “jacketed” pipe. The inner pipe is stainless steel having thermal
conductivity
k
; the outer pipe is carbon steel and assumed to be perfectly
insulated. The annular region between the pipes contains a heat transfer medium
at constant temperature
T
1
. The inner pipe contains polymer material flowing
Carbon steel
T
1
Stainless steel
t
Flow
R
x
Figure P7.17
