Page 14 - Modelling in Transport Phenomena A Conceptual Approach

Contents

Preface vii

1 Introduction 1
1.1 BASIC CONCEPTS ........................... 1
1.1.1 Characteristics of the Basic Concepts ............. 2
1.2 DEFINITIONS .............................. 3
1.2.1 Steady-State ........................... 3
1.2.2 Uniform .............................. 5
1.2.3 Equilibrium ............................ 5
1.2.4 Flux ................................ 5
1.3 MATHEMATICAL FORMULATION OF THE BASIC CONCEPTS 5
1.3.1 Inlet and Outlet Terms ..................... 5
1.3.2 Rate of Generation Term .................... 7
1.3.3 Rate of Accumulation Term ................... 8
1.4 SIMPLIFICATION OF THE RATE EQUATION ........... 8
1.4.1 Steady-State Transport Without Generation ......... 9
1.4.2 Steady-State Transport With Generation ........... 10

2 Molecular and Convective Transport 15
2.1 MOLECULAR TRANSPORT ...................... 15
2.1.1 Newton’s Law of Viscosity .................... 15
2.1.2 Fourier’s Law of Heat Conduction ............... 18
2.1.3 Fick’s First Law of Diffusion .................. 20
2.2 DIMENSIONLESS NUMBERS ..................... 25
2.3 CONVECTIVE TRANSPORT ..................... 26
2.4 TOTAL FLUX .............................. 27
2.4.1 Rate of Mass Entering and/or Leaving the System ...... 29
2.4.2 Rate of Energy Entering and/or Leaving the System ..... 32

3 Interphase Transport and Transfer Coefficients 41
3.1 FRICTION FACTOR .......................... 41
3.1.1 Physical Interpretation of Friction Factor ........... 44
3.2 HEAT TRANSFER COEFFICIENT .................. 45
3.2.1 Convection Heat Transfer Coefficient .............. 45

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