heat and mass transfer data book by c kothandaraman
CONVECTIVE HEAT AND MASS TRANSFER ppt
Ngày tải lên :
30/03/2014, 19:20
... 10
6
kg/m
2
/s.
1.4.5 Convention for Thermal and Mass Transfer Boundary Conditions
A wide variety of thermal and mass transfer boundary conditions can be encoun-
tered in practice. Standard thermal and mass transfer ... mass fraction
β
∗
ma
Coefficient of volumetric expansion with respect to concentration
(kg/m
3
)
−1
˜
β
ma
Coefficient of volumetric expansion with respect to mole fraction
Correction factor for ... with the characteristic
length of the flow filed is the Knudsen number:
Kn
l
c
= λ
mol
/l
c
. (1.6.1)
Conventional fluid mechanics and heat transfer theory, in which fluids act as
continua and there...
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Heat and Mass Transfer in Porous Media pdf
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31/03/2014, 16:20
... vapour core and a 2D capillary structure, such as metallic meshes or crossed
grooves.
1.7 Variable Conductance Heat Pipe
A variable conductance heat pipe (VCHP) is an active thermal control device ... applications where there is a demand to reduce (controlled conductance) or to
block (OFF mode) the thermal conductance during some operational modes of the
spacecraft. The heat pipe conductance ... devices. Appeared almost three decades ago for space applications,
heat pipes are now extensively and successfully applied to electronics and
microelectronics cooling (Fig. 8), bio-medical products...
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heat and mass transfer
Ngày tải lên :
02/04/2014, 15:27
... as
convective mass transfer corresponds to convective mass transfer. Mass transfer
by diffusion and convection are the only sorts of mass transfer. Radiative heat
transfer has no corresponding mass transfer ... 1.34:Ratio(kA)
co
/ (kA)
cc
= N
co
i
/N
cc
i
of the transfer capabilities in cocur-
rent (index co) and countercurrent (index cc) flows as a function of ε
i
and C
i
ϑ
i
(i =1,2) are important, cf. Fig. ... characteristic of a countercurrent heat ex-
changer. It is invariant with respect to an exchange of the indices 1 and 2. Using
the ratios of C
1
and C
2
=1 /C
1
from (1.99) and (1.100), explicit...
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fundamentals of heat and mass transfer
Ngày tải lên :
02/04/2014, 15:51
... Circular Tubes 544
8.6 Convection Correlations: Noncircular Tubes and the Concentric
Tube Annulus 552
8.7 Heat Transfer Enhancement 555
Contents
xv
FMContents.qxd 2/21/11 6:10 PM Page xv
(Carnot) ... surface
temperature of 200 C in a room for which the air
and the walls are at 25 C. The coefficient character-
izing heat transfer by natural convection depends
on the surface temperature and, ... analysis of convection.
Convection heat transfer may be classified according to the nature of the flow. We speak
of forced convection when the flow is caused by external means, such as by a fan, a...
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fundamentals of momentum, heat, and mass transfer 5th edition
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02/04/2014, 15:51
... physical contact, for example, gravity and
electrostatic forces. On the contrary, pressure and frictional forces requi re physical contact
for transmission. As a surface is required for the action ... Heat- Transfer Coefficient 392
23.13 Closure 393
24. Fundamentals of Mass Transfer 398
24.1 Molecular Mass Transfer 399
24.2 The Diffusion Coefficient 407
24.3 Convective Mass Transfer 428
24.4 Closure ... general case is one in which the velocity
varies over the cross-sectional area.
EXAMPLE 2 Let us consider the case of an incompressible flow, for which the flow area is circular and the
velocity profile...
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incropera fundamentals of heat and mass transfer
Ngày tải lên :
02/04/2014, 15:52
...
function of current for selected convection coefficients.
COMMENTS: (1) For forced convection over the cylinder, the convection heat transfer coefficient is ... of heater or switch, (5) Switch surface, A
s
, loses heat only by convection.
ANALYSIS: Define a control volume around the bimetallic switch which experiences heat
input from the heater and convection ... transferring heat by convection and convection coefficients well in excess
of 100 W/m
2
⋅K may be achieved.
PROBLEM 1.3
KNOWN:
Dimensions, thermal conductivity and surface temperatures of a concrete...
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momentum, heat, and mass transfer fundamentals
Ngày tải lên :
02/04/2014, 15:53
...
of
continuum
Chapter 1 Problems
2
THE
MASS BALANCES
2.1
The
Macroscopic Mass Balances
Figure 2.1
-
1 System for
mass
balances
2.1.1 The macroscopic total
mass
balance
Accumulation ...
consider. On the other hand, momentum (which can
be
created
or destroyed
by
applied forces), mass of
an
individual species (which can be
created or destroyed by chemical reaction), and ...
balance
Generation
of
mass
of
a
species
Accumulation of mass of a
species
Input
and
output of mass of
a
species
Example
2.1.2-1
Macroscopic species
mass
balance with
zero
-0
rde...
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Fundementals of heat and mass transfer kotandaraman
Ngày tải lên :
08/04/2014, 10:55
... are convection coefficients.
Example 1.4: A slab 0.2 m thick with thermal conductivity of 45 W/mK receives heat from a
furnace at 500 K both by convection and radiation. The convection coefficient ... convection heat transfer
Example 1.2: Determine the heat transfer by convection over a surface of 0.5 m
2
area if the
surface is at 160 C and fluid is at 40 C. The value of convective heat transfer ... as contact resistance. A
significant temperature drop develops at
the interface and this has to be taken into
account in heat transfer calculation. The
contact resistance depends on the surface
roughness...
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Heat and Mass Transfer Modeling and Simulation Part 1 pptx
Ngày tải lên :
19/06/2014, 10:20
... description and analysis of heat and
mass transfer processes in a fin -and- tube air heater. Hydrogen production by steam
reforming and the process intensification strategies are discussed in chapter ... solute concentration (C
A
)
Contents
Preface IX
Chapter 1 Modeling of Batch and Continuous
Adsorption Systems by Kinetic Mechanisms 1
Alice F. Souza,
Leôncio Diógenes T. C mara
... aspects of heat and/ or mass transfer,
analytical/numerical solutions and optimization of the processes.
The first chapter deals with the description and mass transfer analysis of fixed-bed
chromatographic...
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Heat and Mass Transfer Modeling and Simulation Part 2 ppt
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19/06/2014, 10:20
... (R
p ,c
)
CATHODE
CONTRIBUTION
Ohmic
resistance
(R
Ω
)
Charge
transfer CPE
Charge transfer
resistance (R
ct
)
Mass transfer
resistance (R
mt
)
CHARGE
TRANSFER
CONTRIBUTION
MASS TRANSFER
CONTRIBUTION
Mass ...
Heat and Mass Transfer – Modeling and Simulation
26
circuit constant phase element and resistance, related to the charge transfer processes
(kinetic), and another parallel mini-circuit constant ... element and resistance, associated
to mass transfer, is proposed [see Fig. 7(a)]. Table 2 also collects the values of the
corresponding mass transfer resistances.
As it can be seen, and concomitantly...
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Heat and Mass Transfer Modeling and Simulation Part 3 pot
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19/06/2014, 10:20
... circuit voltage
C
R
C
reactant concentration at the
catalytic layer
b Tafel slope
C
P
C
product concentration at the
catalytic layer
j experimental current density
C
R
cat
reactant ... efficiency must account
for the simultaneous heat and mass transfer on the cooling surface. Many experimental, and
few numerical, studies have been carried out to study the heat and mass transfer ...
resistance for the charge
transfer process
Q flow of gas (CPE)
ct
constant phase element for the
charge transfer process
à gas viscosity R
mt
resistance for the mass transfer
process
L thickness...
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Heat and Mass Transfer Modeling and Simulation Part 4 docx
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19/06/2014, 10:20
... micro-reactors instead of conventional reactors, which can reduce the heat
and mass transport resistance by decreasing the transport distance
[8]
; in addition,
microwave direct heating and ... component of CH
3
OH, H
2
O, H
2
, CO
2
and CO respectively. The
coefficients of
D, μ and λ are gas mixture’s diffusion coefficient, viscosity coefficient and
thermal conductivity respectively. ... of the
reactor performance by enhancing heat and mass transfer and this can be divided to three
classes. One way is to adopt new catalyst materials and additives such as coating catalyst,
nanometer...
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Heat and Mass Transfer Modeling and Simulation Part 5 pdf
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19/06/2014, 10:20
... characters of MSR in the micro-reactor with
coating catalyst, effects of catalytic surface distribution, catalytic activity distribution on the
micro-reactor performance were investigated by ... predominant mechanism for bonding was mechanical
interlocking, especially for the Cu-Al
2
O
3
composite and CuO/ZnO/Al
2
O
3
catalytic coating.
Cold sprayed CuO/ZnO/Al
2
O
3
catalytic coating ... significantly and this effect can be applied to any catalytic
reaction with strong heat effect. And it will be more useful in large scale catalyst reactors
due to the increasing heat and mass resistance...
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Heat and Mass Transfer Modeling and Simulation Part 6 pptx
Ngày tải lên :
19/06/2014, 10:20
...
C
molar concentration, kmol/m
3
P
mixed gas pressure, Pa
p
C
Isobaric specific heat capacity,
J/(mol·K)
mixed gas viscosity coefficient,
kg/(m·s)
D
effective diffusion coefficient, ... presented by means of wall temperature
distribution and convective heat transfer coefficients.
2. Mathematical formulation
2.1 Natural convection
Consider laminar free convection along a vertical ... forced convection (Maïga et al. 2005) as well as
in mixed convection, using nanofluids can produce a considerable enhancement of the heat
transfer coefficient that increases with the increasing...
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Heat and Mass Transfer Modeling and Simulation Part 7 doc
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19/06/2014, 10:20
... nanoparticle volume fraction.
6. Nomenclature
Cp specific heat capacity J.kg
-1
.K
-1
g acceleration of the gravity m.s
-2
h heat transfer coefficient W.m
-2
.K
-1
Heat and Mass Transfer ... CTV CTV CTV CTV
YYY
s
plash fill trickle fill film fill
CC CC CC
123
CTV CTV CTV CTV
CCCC (68)
, 1, ,3
iii
CTV
Ceyi (69)
Common values for unit costs
i
e are reported in Table 3. ... fixed cooling
tower cost (
CTF
C ), packing volume and air flow rate (Kintner-Meyer & Emery, 1995),
CTF CTV fr fi CTMA a
CAP C C A L C m (67)
CTV
C depends on the type of packing;...
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