ire difference in a
if some chemical
in diﬂerence in a
)r heat transfer, a
otential for trans
:rm mass transfer
)ulk ﬂuid motion,
arm mass transfer
an of water being
id motion due to
felative motion of
5. One example is
Dke stack into the
‘0 dry air, a
724 Chapter 12 I Radiation: Processes and Properties
Whave come to recognize that heat transfer by conduction and convec
requires the presence of a temperature gradient in some form of matter. In con _
heat transfer by ther
970
Appendix C l OneDimensional, SteadySlate Conduction with Generation
TABLE C.3 One—Dimensional, Steady—State Solutions to the Heat
Equation for Uniform Generation in a Plane Wall with One
Adiabatic Surface, a Solid Cylinder, and a Solid Sphere
Temp
694 Chapter 11 I Heat Exchangers
or
: 2.1(1889 W/K) =
2
100 W/m2  K 39‘7 m
I!
Comments: With the heat exchanger sized (A, = 39.7 ml) and placed into 0
tion, its actual performance is subject to uncontrolled variations in the exhau
=oo335
I: 0.9664
= 0.84 <1
at the cover plate is
9E EM, (5800 K). It
, in which case it is
I}, appearing in both
in possible to replace
: properties associated
ionsider conditions for
rature T5, within which
LbOdlCS are small rela
adiation ﬁeld, which is
13.1 I The View Factor 815
summation rule, Equation 13.4, to each of the surfaces in the enclosure, In addition,
N(N — l)/2 view factors may be obtained from the MN — l)/2 applications of the
reciprocity relation, Equation 13.3, which are possible for the
late of length 0.5 m and
,‘ajrstream at a tempera
pf 10 m/s. Because of
t is turbulent over the
ties of segmented, inde—
'5 attached to the lower
pproximately isothermal
.e. The electrical heater
he positions x, = 0.2 m
schematic.
Heater segment,
T, = 47
634
Chapter 10 I Boiling and Condensation
where C” = 0.0128 and n = 1.0. Substituting numerical values, the bo‘_
heat ﬂux is
q’; = 279 x 10‘6 N  s/m2 x 2257 x 103 J/kg
X [9.8 m/s2 (957.9 — 0.5956) kg/m3 1’2
58.9 x 10‘3 N/m
x< 4.217 x 103J/kg  K x 18°C
0
I Problems
gig/$2,111, = 440 x 10‘6
Iiion, the nucleate boil
d n = 1.7.
atmospheric pressure, and values of TI = 133.7°C
and T2=158.6°C are recorded. If n = 1, what
value of the coefﬁcient CL] is associated with the
I Problems
7.70 A spherical, underwater instrument pod used to make
soundings and to measure conditions in the water has a
diameter of 85 mm and dissipates 300 W.
with the observa '
he
ml; 9.7 ‘
ancydriven ﬂows on
ontal cold (T, < Tm):
hot (T5 > Tm) plates: '
_ p surface of cold plal;
tlom surface of cold
' , (0) top surface of hot
, and (d) bollom
cc of hot plate.
Since then, howev_
or the top and bot an
ppropriate for the t 
ely, wh
498
Chapter 8 I Internal Flow
or
dqconv : mcpdTm ( '
Equation 8.36 may be cast in a convenient form by expressing the rate of .5
surface perimeter (P = 7TD for a circular tube). Substituting from Equation 8.7 .'
follows tha
528
8.9
Convection Mass Transfer
Chapter 8 l Internal Flow
2. Solving Equation 8.42 over the range 0 S x S L yields the axial variation of
mean temperature for the two extreme processing temperature channels;
shown below.
150
100 .
idii r, and r0, re—
hiponents, and at
Lstribution in the
int? How do the
o
.
l in a thinwalled
i, and the exother
i but temperature
ip(—A/Ta), where
mixture temper—
' by an insulating
nductivity k, and
nsulation experi
tdiation exchange
ings, respec


l:=i.5W/mK,a=
lNeglecting convecti I
in of 10 mm, determin'
'e and 30 mm from th
ie of 1 min.
1 .
Eper in Example 5.
F temperature of 20°
53 net radiant ﬂux a
iDiﬂerence Equatio _
ll
420 Chapter 7 I External Flow
respectively, and the results are represented by the solid curves of the follo '
schematic:
300
250 r
200
h, (W/mZK)
G
O
100
50
8.00 0.05 0.10 0.15 0.20 0.25 0.30
The {"2 decay of the laminar convection coefﬁcient is
e that the solution to
(6.44)
geometry and may be
the free stream, the
:e of geometry on the;
inay be expressed as
efficient is
(6.45)
i (6.46)
Equation 6.46 states
liderable importance
dimensionless space
geometry we expect
lblicable. That is, we
Elues f
.symbolic form,
'stribution.
eter D = ax,
banal conditions
l .
pnstant 1ndepen
ed to determine
3.2 I An Alternative Conduction Analysis 1 15
where A = 7702/4 = wa2x2/4. Separating variables,
4th dx
nazxz
= ~de
Integrating from x, to any x withi
{abolic proﬁles).
Ectangular ﬁn with
n is of nonuniform
; must be retained,
ttial or hyperbolic
3.6 I Heat Transfer ﬁom Extended Surfaces I 5 1
functions. As a special case, consider the annular ﬁn shown in the inset of Figure 3.19.
Although the ﬁn t
[\D
[\9
5.5
The Plane Wall with Convection
Chapter 5 l Transient Conduction,
where the Biot number is Bi E hL/k. In dimensionless form the functional depe
dence may now be expressed as
0* =ﬂx*, F0, Bi)
Recall that a similar functional depend
302
5.10
F miteDifference Methods
«5.3; Analytical solutions
for some simple
two and three—
dimensional
geometries are found
in Section 55.2.
Chapter 5 I Transient Conduction
Analytical solutions to transient problems are restricted to simple geomet
214
Chapter 4 I TwoDimensional, SteadyState Conduction
Each node represents a certain region, and its temperature is a measure of
average temperature of the region. For example, the temperature of the node m, n
Figure 4.4a may be viewed as the av
250
4.73
T
6mm
Assuming onedimensional conduction and using a
ﬁnitedifference method representing the grid by ten
nodes in the x direction, estimate the temperature distri
bution for the grid. Him: For each node requiring an
energy balance, use the lin
58 Chapter 2 I Introduction to Conduction
Recall that conduction refers to the transport of energy in a medium due to a
temperature gradient, and the physical mechanism is one of random atomic or mole
cular activity. In Chapter 1 we learned that conduc
contact resistance of R2,. = 3 X 10“4 m2  K/W. The
convection heat transfer coefﬁcient at the outer surface of
the sheath is 10 W/m2  K, and the temperature of the am—
bient air is 20°C. If the temperature of the insulation may
not exceed 50°C, what is
fixed geome
is on the rate
:tric current.
L4 Q/m) in a
.is circulated
16 foregoing
rrents in the
safety rea
nansfer by
10.4 W/m).
ing the rod
tld have to
Dr 11 = 250
5‘.
ext is espe
amment 1,
r this pur
freeform
determine
feature to
ature and
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Chapter 6 Viscous Flow in Ducts
P6.55 The reservoirs in Fig. P6.55 contain water at 20C. If the
EES
pipe is smooth with L 4500 m and d 4 cm, what
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Comprehensive Problems
451
Q
Weee!
Tube
4.00 m
Ladder
Sliding board
Pump
Water
1.00 m
C6.3
C6.5
the pipe inlet to its exit. Neglect any minor losses