ELEMENTS OF HEAT AND MASS TRANSFER

Cover
Preface to the Second Edition
Contents
1. Transfer Processes
	1.1 Introduction
	1.2 Nature of Transfer Processes
	1.3 Concept of Driving Potential
	1.4 Physical Mechanisms
	1.5 Heat Transfer in Fluids–Convection
	1.6 Convective Mass Transfer
	1.7 Radiant Energy Exchange
	1.8 Descriptions of Some Heat and Mass Transfer Processes
		1.8.1 Evaporative air cooler
		1.8.2 Moisture Pick-up from Lakes
		1.8.3 Spray Drying
		1.8.4 Respiratory Gas Exchange in Lungs
		1.8.5 Ablation of Meteorites Entering Atmosphere
		1.8.6 Burning of Carbon in Air
	1.9 Heat Transfer from Human Body
2. Conduction: Heat Transfer in Stationary Medium
	2.1 Introduction
	2.2 A Physical Law for Rate of Heat Transfer
	2.3 Methodology
	2.4 Basic Equation of Heat Conduction
	2.5 Boundary and Initial Conditions
		2.5.1 Specified-Temperature Condition
		2.5.2 Specified-Flux Condition
		2.5.3 Specified-Convection Condition
		2.5.4 Condition at the Interface of Two Solids
	2.6
Thermal Properties of Matter
		2.6.1 Thermal Conductivity
		2.6.2* Physical Basis of Conductivity
		2.6.3 Thermal Diffusivity
	2.7
Normalisation of the Heat Conduction Problem
		2.7.1* Concept of Similarity
		2.7.2* Basis of Approximations
3. Steady-State Conduction
	3.1
Introduction
	3.2
Steady-state Conduction in a Slab
		3.2.1 Temperature Profile
		3.2.2 Conduction with Convective Boundary Condition
		3.2.3 Thermal Resistance of a Slab
		3.2.4 Equivalent Resistance to Heat Loss by Radiations to the Surroundings
		3.2.5 Significance of Biot Number
		3.2.6 Contact Resistance
	3.3
Heat Conduction
Across a Cylindrical Shell
		3.3.1 Temperature Profile and Heat Current
		3.3.2 Thermal Resistance
		3.3.3 The Critical Thickness of Cylinder Insulation
	3.4
Steady Conduction in a Spherical Shell
		3.4.1 Temperature Distribution
		3.4.2 Lower Bound of Heat Transfer Coefficient h
	3.5 Fins
		3.5.1 Pin-Fins of Constant Cross-Section
		3.5.2 Fin Performance: Fin Effectiveness and Fin Efficiency
		3.5.3 Fins of Other Geometry
		3.5.4 Heat Sinks for Electronic Components
		3.5.5 Fins of Dinosaurs
	3.6
Conduction with Uniformly Distributed Heat Sources
		3.6.1 Conduction Across a Plane Wall with Distributed Heat Sources
		3.6.2 Radial Conduction in a Cylindrical Rod with Distributed Heat Sources
	3.7 Steady-state Conduction in Two-Dimensions
		3.7.1 An Analogy with Ideal Fluid Flow
		3.7.2 Conduction Shape Factors
4. Transient Conduction
	4.1 Transient Conduction
	4.2 Transient Conduction through an Infinite Slab
	4.3 Transient Conduction in Long Cylinders
	4.4 Transient Conduction in Sphere
	4.5 Significance of Biot Number
	4.6 Transient Heating of Bodies with Negligible Internal Resistance
	4.7 Transient Conduction in Semi-Infinite Solid
		4.7.1 Effect of Step Change in Temperature at the Boundary of a Semi-Infinite Solid
		4.7.2 Concept of Penetration Depth
		4.7.3 Significance of Thermal Diffusivity
		4.7.4 Significance of Fourier Number
		4.7.5 Food Cellar
		4.7.6 Transient Conduction in Semi-infinite Slab with other Boundary Conditions
		4.7.7 Contact of Two Infinite solids
	4.8 Transient Conduction in Multi-dimensions
5. Numerical Methods forConduction Problems
	5.1
Introduction
	5.2
Some Elementary Ideas
		5.2.1 The Nodal Mesh
		5.2.2 Estimates of Derivatives
	5.3 One- dimensional Conduction
		5.3.1 Steady–State 1–D Conduction in a Slab
	5.4 One- dimensional Fin
	5.5 Two-dimensional Steady-state Conduction
		5.5.1 An Interior Node
		5.5.2 Node at a Plane Surface
	5.6 Finite- Difference Formulation of 2-D Problems
	5.7
Methods of Solution
	5.8
Unsteady Heat Conduction in One-Dimension
		5.8.1 Implicit and Explicit Schemes
	5.9
Unsteady Conduction in
Two-Dimensions
		5.9.1 Energy Balance Equation for an Interior Cell
		5.9.2 Node at a Plane Wall
		A5
Appendix: Matlab Programmes
		A5.1 Steady– state 1–D conduction in the slab of Sec. 5.3.1
		A5.2 Example 5.1: 1–D conduction in a slab with convective boundary conditions
		A5.3 Example 5.2: Heat transfer across the walls of a thick cylindrical tube
		A5.4 Example 5.3: Electric blanket
		A5.5 One–dimensional fin
		A5.6 Example 5.4: Tapered fin
		A5.7 Gauss–elimination procedure
		A5.8 Gauss-Sidel procedure
		A5.9 Example 5.7 Unsteady conduction in a slab
		A5.10 Example 5.8: Semi-infinite solid
6. Convection– Empirical Approach
	6.1 Introduction
	6.2 Transpiration Cooling – The Basic Mechanism of Heat Convection
	6.3 Convection from a Hot Body in a Fluid Stream
	6.4 Non- Dimensional Parameters in Convection
		6.4.1 Forced Convection
		6.4.2 Significance of the Various Non-dimensional Parameters
	6.5 Transport in Turbulent Flows
	6.6
External Forced Convection
		6.6.1 Concept of Boundary Layer
		6.6.2 Estimating the Thickness of Velocity Boundary Layers
		6.6.3 Thickness of Thermal Boundary Layers
		6.6.4 Reynolds Analogy
		6.6.5 Turbulent Boundary Layers
		6.6.6 Separated Flows
		6.6.7 Forced Convection from Cylinders
		6.6.8 Forced Convection from a Sphere
		6.6.9 Forced Convection across Banks of Tubes
		6.6.10 Forced Convection in Packed Beds
	6.7
Free or Natural Convection
		6.7.1 Significance of Grashof Number
		6.7.2 Vertical Walls
		6.7.3 Free Convection from Horizontal and Inclined Walls
		6.7.4 Free Convection from Horizontal Cylinders
		6.7.5 Free Convection in Rectangular Enclosures
		6.7.6 Quick Formulae for Free–Convection in Air
	6.8
Forced Convection in Pipes and Ducts
		6.8.1 Full– Development of Velocity Profile
		6.8.2 Concept of Bulk Temperature
		6.8.3* The Concept of Full–Development of Temperature Profiles
		6.8.4 Nusselt Number for Fully–Developed Flows
		6.8.5 Thermal Entry Length
	6.9
Heat
Transfer in Condensation
		6.9.1 Correlations for Heat Transfer in Film Condensation
		6.9.2 Laminar Film Condensation on Horizontal Pipes
	6.10
Heat
Transfer in Boiling
		6.10.1 Physical Mechanisms
		6.10.2 Variation of Boiling Heat Flux with Excess Temperature
		6.10.3 Empirical Correlations
	6.11 Summary of Some Useful Correlations for Heat Convection
7. Convection– 
Analytic Approach
	7.1
Introduction
	7.2 Transpiration Cooling – Illustrating the Basic Mechanism of Heat Convection
	7.3
Basic
Approach in Analysing a Convection Problem
	7.4
Concept of Full-development Revisited
	7.5
Heat
Transfer in Couette Flow
		7.5.1 Velocity Profile
		7.5.2 Temperature Profile
		7.5.3 Recovery Temperature
	7.6
Flow Through
a Circular Tube
		7.6.1 Fully– Developed Velocity Profile
		7.6.2 Constant Wall–Flux Case – Axial Gradient of Temperature
		7.6.3 Constant Wall–Flux Case—Temperature Profile
		7.6.4 Constant Wall Temperature Case—Log Mean Temperature Difference
	7.7
Heat
Transfer in External Convection
		7.7.1 Thermal Boundary Layer for Pr << 1
		7.7.2 Heat Convection on a Flat Plate for the case of Pr~1
	7.8 Free Convection
	7.9
Film Condensation on a
Vertical Plate
		A7
Appendix: Conservation Laws for Heat Convection
		A7.1 Eulerian or Field Approach
		A7.2 Control Volume
		A7.3 Reynolds Transport Theorem
		A7.4 Conservation Laws
		A7.5 Conservation of Mass —The Continuity Equation
		A7.6 The Momentum Equation
		A7.7 Energy Equation
		A7.8 Using the Conservation Equations
		A7.9 Non–Dimensionalization of the Equations of Heat Convection
		A7.10 Similarity Parameters
		A7.11 Nusselt Number – the Dimensionless Heat Transfer Coefficient
		A7.12 Significance of the Various Similarity Parameters
8. Radiative Transfer
	8.1 Introduction
	8.2
Emission of Radiation
		8.2.1 Electromagnetic Spectrum
		8.2.2 Emissive Power of a Surface
		8.2.3 Irradiation
		8.2.4 Reflection, Absorption and Transmission
		8.2.5 Blackbody
		8.2.6 Kirchhoff Laws
		8.2.7 Radiosity
	8.3
Radiation Intensity
		8.3.1 Radiation Intensity of Black-body Emissions
		8.3.2 Radiation Intensity in Non-Black Body Radiations
		8.3.3 Incident Intensity and Irradiation
	8.4
Laws of Black-Body Radiation
		8.4.1 Stefan-Boltzmann Law
		8.4.2 Monochromatic or Spectral Emissions
		8.4.3 Planck Distribution Law
	8.5
Radiative Heat Exchange Between Black-body Surfaces
	8.6 Configuration Factor Algebra
		8.6.1 Summation Rule
		8.6.2 Reciprocity Relation
		8.6.3 A Radiation Enclosure of N Surfaces
		8.6.4 Hottel Cross-Strings Method
	8.7 Determining Configuration Factors from First Principles
		8.7.1 Configuration Factors for Infinitesimal Surfaces
		8.7.2 Configuration Factor for Finite Surfaces
	8.8
Equivalent Circuits for Blackbody Enclosures
	8.9
Radiation Properties of Real Surface
		8.9.1 Emission from Real Surface
		8.9.2 Spectral Effects in Surface Absorption, Reflection and Transmission
	8.10 Radiative Transfer Between Grey-Diffuse Surfaces
		8.10.1 The Equivalent Circuit
		8.10.2 The Matrix Formulation
	8.11 Free-Molecular Flow
9. Mass Transfer
	9.1 Introduction
		9.1.1 Diffusion
		9.1.2 Mass Convection
		9.1.3 Free-Molecular Transfer
	9.2 Definitions of Quantities Involved in Mass Transfer
		9.2.1 Concentrations
		9.2.2 Velocities
		9.2.3 Fluxes
	9.3 A Physical Law for Diffusion: Fick Law
	9.4
Species Conservation Equation
	9.5
Boundary Conditions
		9.5.1 Specified Concentration Condition
		9.5.2 Specified Flux Condition
		9.5.3 Specified Transfer-Coefficient Condition
	9.6 Steady-state Diffusion in a Dilute Solution in a Stationary Medium
	9.7 Steady-state Non-Dilute Diffusion with one Component Stationary
	9.8 Steady-state Diffusion with Homogeneous Chemical Reaction
	9.9 Transient Diffusion in Dilute Solutions in Stationary Media
	9.10 Unsteady Diffusion into a Semi-infinite Solid
10. Convective Mass Transfer
	10.1 Introduction
	10.2
Forced
Convective-Mass Transfer
	10.3
Using Correlations in Mass Convection Problems
	10.4 Evaporative Cooling
	10.5 Absorption of a Gas by a Falling Film of Liquid
	A10 Appendix: Governing Equations for Convective Mass Transfer
11. Heat and Mass Exchangers
	11.1 Heat Exchangers
	11.2 In-line Heat Exchangers
	11.3 Analysis of Heat Exchanger Performance
		1.3.1 Fouling in Heat Exchangers
		11.3.2 Overall Heat Transfer Coefficient
		11.3.3 Log Mean Temperature Difference (LMTD) Analysis
	11.4 Multi-pass and Cross-flow Heat Exchangers
	11.5 Effectiveness-Number of Transfer Units (∈-NTU) Method
	11.6 Mass Exchangers
	11.7 Effectiveness - NTU Method for Analysis of Gas Absorbers
	11.8 Adiabatic Humidifier
	Appendix : Physical Constants and Property Values
	Index