vii TABLE OF CONTENTS CHAPTER ITEMS TITLE PAGE i DECLARATION ii DEDICATION iii ACKNOWLEDGEMENT iv ABSTRACT v ABSTRAK vi TABLE OF CONTENTS vii LIST OF TABLES x LIST OF FIGURES xi LIST OF SYMBOLS xv LIST OF APPENDICES 1 2 PAGE xviii INTRODUCTION 1.1 Introduction 1 1.2 Background of Research 2 1.3 Statement of Problem 5 1.4 Objectives and Scope of Research 5 1.5 Significance of Research 6 1.6 Outlines of Thesis 8 LITERATURE REVIEW 2.1 Introduction 10 2.2 Convective Heat Transfer of Nanofluids 10 2.3 Convection over a Continuous Stretching 23 Surface subjected to Suction or Injection viii 2.4 Convection over a Stretching Surface in the 26 Presence of Magnetic Field 2.4 Convection over a Stretching Surface in the 31 Presence of Suction or Injection and Magnetic Field 3 4 THE GOVERNING EQUATIONS 3.1 Introduction 34 3.2 Conservation of Mass 34 3.3 Conservation of Momentum 39 3.4 Conservation of Energy 41 3.4 Boundary Layer Scale Analysis 43 NATURAL CONVECTIVE BOUNDARY LAYER FLOW OF A NANOFLUID PAST A VERTICAL FLAT PLATE 5 4.1 Introduction 49 4.2 The Governing Equations 49 4.3 Similarity Transformation 51 4.4 Numerical Computation 54 4.5 Results and Discussion 56 4.6 Conclusion 64 FORCED CONVECTIVE BOUNDARY LAYER FLOW OF A NANOFLUID PAST A CONTINUOUS STRETCHING SURFACE 5.1 Introduction 66 5.2 The Governing Equations 66 5.3 Similarity Transformation 68 5.4 Results and Discussion 70 5.5 Conclusion 82 ix 6 FORCED CONVECTIVE BOUNDARY LAYER FLOW OF A NANOFLUID PAST A CONTINUOUS STRETCHING SURFACE WITH SUCTION OR INJECTION IN THE PRESENCE OF MAGNETIC FIELD 7 6.1 Introduction 83 6.2 Problem Formulation 83 6.3 Results and Discussion 86 6.4 Conclusion 99 CONCLUSIONS 7.1 Summary of Research 101 7.2 Suggestions for Future Research 102 REFERENCES 104-109 Appendices A-H 110-163 x LIST OF TABLES TABLE NO. TITLE PAGE 4.1 The values of reduced Nusselt number, −θ ′(0) and reduced Sherwood number, −φ ′(0) for various values of Prandtl number, Pr when Le = 2, Nb = 0.5, Nt = 0.5 and Nr = 0.5 64 4.2 The values of reduced Nusselt number, −θ ′(0) and reduced Sherwood number, −φ ′(0) for various values of Lewis number, Le when Pr = 10, Nb = 0.5, Nt = 0.5 and Nr = 0.5 64 5.1 Comparison of results for the reduced Nusselt number, −θ ′(0) of a regular fluid for various values of Prandtl number, Pr when m = 1, Nb = Nt = 10-4, Le = 10 71 5.2 Comparison of present results for the reduced Nusselt number, −θ ′(0) with Khan and Pop (2010) 80 5.3 Comparison of present results for the reduced Sherwood number, −φ ′(0) with Khan and Pop (2010) 81 6.1 Comparison of results for the reduced Nusselt number, −θ ′(0) of a regular fluid for various values of Prandtl number, Pr when m = 1, Nb = Nt = 10-4, Le = 10, d = 0 and Mn = 0 87 6.2 Results of − f ′′(0) , −θ ′(0) and −φ ′(0) for various values of suction or injection parameter, d when Pr = 2, Le = 2, Nb = 0.5, Nt = 0.5, m = 1, and Mn = 0 99 6.3 Results of − f ′′(0) , −θ ′(0) and −φ ′(0) for various values of magnetic parameter, Mn when Pr = 2, Le = 2, Nb = 0.5, Nt = 0.5, m = 1, and d = 0 99 xi LIST OF FIGURES FIGURE NO. TITLE PAGE 3.1 Illustration of nanofluid control volume for the derivation of continuity equation 35 3.2 Illustration of nanofluid control volume for the derivation of energy equation 41 3.3 Illustration of similarity variables 44 4.1 Physical model and coordinate system for vertical flat plate 50 4.2 Plots of the velocity f ′(η ) , temperature θ (η ) , and nanoparticle fraction φ (η ) profiles for the case Pr = 2, Le = 2, Nr = 0.5, Nb = 0.5, Nt = 0.5. 55 4.3 Plots of dimensionless similarity functions f (η ), f ′(η ), θ (η ), φ (η ) for the case Pr = 10, Le = 10, Nr = 0.5, Nb = 0.5, Nt = 0.5 58 4.4 Effect of Prandtl number, Pr on the velocity profiles 58 4.5 Effect of Prandtl number, Pr on the temperature profiles 59 4.6 Effect of Prandtl number, Pr on the nanoparticle fraction profiles 59 4.7 Effect of Lewis number, Le on the temperature profiles 60 4.8 Effect of Lewis number, Le on the nanoparticle fraction profiles 60 4.9 Effect of Brownian motion parameter, Nb on the temperature profiles 61 4.10 Effect of Brownian motion parameter, Nb on the nanoparticle fraction profiles 61 xii 4.11 Effect of thermophoresis parameter, Nt on the temperature profiles 62 4.12 Effect of thermophoresis parameter, Nt on the nanoparticle fraction profiles 62 4.13 Effect of buoyancy ratio parameter, Nr on the temperature profiles 63 4.14 Effect of buoyancy ratio parameter, Nr on the nanoparticle fraction profiles 63 5.1 Physical model and coordinate system for stretching surface 67 5.2 Effect of velocity stretching parameter, m on the temperature profiles 74 5.3 Effect of velocity stretching parameter, m on the nanoparticle fraction profiles 74 5.4 Effect of Prandtl number, Pr on the temperature profiles 75 5.5 Effects of Lewis number, Le on the temperature profiles 75 5.6 Effects of Lewis number, Le on the nanoparticle fraction profiles 76 5.7 Effects of Brownian motion parameter, Nb on the temperature profiles 76 5.8 Effects of Brownian motion parameter, Nb on the nanoparticle fraction profiles 77 5.9 Effects of thermophoresis parameter, Nt on the temperature profiles 77 5.10 Effects of thermophoresis parameter, Nt on the nanoparticle fraction profiles 78 5.11 Effects of Brownian motion parameter, Nb and thermophoresis parameter, Nt on the reduced Nusselt number, −θ ′(0) 78 5.12 Effects of Brownian motion parameter, Nb and thermophoresis parameter, Nt on the reduced Sherwood number, −φ ′(0) 79 6.1 Effect of suction or injection parameter, d on the velocity profiles 90 xiii 6.2 Effect of suction or injection parameter, d on the temperature profiles 90 6.3 Effect of suction or injection parameter, d on the nanoparticle fraction profiles 91 6.4 Effect of Brownian motion parameter, Nb on the temperature in the presence of suction or injection 91 6.5 Effect of Brownian motion parameter, Nb on the nanoparticle fraction profiles in the presence of suction or injection 92 6.6 Effect of thermophoresis parameter, Nt on the temperature profiles in the presence of suction or injection 92 6.7 Effect of thermophoresis parameter, Nt on the nanoparticle fraction profiles in the presence of suction or injection 93 6.8 Effect of magnetic parameter, Mn on the velocity profiles 93 6.9 Effect of magnetic parameter, Mn on the temperature profiles 94 6.10 Effect of magnetic parameter, Mn on the nanoparticle fraction profiles 94 6.11 Effect of Brownian motion parameter, Nb on the temperature profiles in the presence of magnetic field 95 6.12 Effect of Brownian motion parameter, Nb on the nanoparticle fraction profiles in the presence of magnetic field 95 6.13 Effect of thermophoresis parameter, Nt on the temperature profiles in the presence of magnetic field 96 6.14 Effect of thermophoresis parameter, Nt on the nanoparticle fraction profiles in the presence of magnetic field 96 6.15 Effect of magnetic parameter, Mn on the reduced Nusselt number, −θ ′(0) for various values of Brownian motion parameter, Nb 97 6.16 Effect of magnetic parameter, Mn on the reduced Sherwood number, −φ ′(0) for various values of Brownian motion parameter, Nb 97 xiv 6.17 Effect of magnetic parameter, Mn on the reduced Nusselt number, −θ ′(0) for various values of thermophoresis parameter, Nt 98 6.18 Effect of magnetic parameter, Mn on the reduced Sherwood number, −φ ′(0) for various values of thermophoresis parameter, Nt 98 C.1 The grid for difference approximations 128 D.1 Plots of the velocity f ′(η ) , temperature θ (η ) , and nanoparticle fraction φ (η ) profiles for the case Pr = 2, Le = 2, Nb = 0.5, Nt = 0.5, m = 1, d = 0, Mn = 3 149 xv LIST OF SYMBOLS Roman Letters B - magnetic field vector B( x) - magnetic field in the y-direction B0 - constant cp - nanoparticle specific heat C - nanoparticle volume fraction Cf - skin-friction coefficient Cw - nanoparticle volume fraction at the surface C∞ - ambient nanoparticle volume fraction d - suction/injection parameter DB - Brownian diffusion coefficient DT - thermophoretic diffusion coefficient f - dimensionless stream function F - body forces vector g - gravity acceleration vector hp - nanoparticle specific enthalpy I - identity vector jp - nanoparticle mass flux j p, B - mass flux due to Brownian diffusion jp,T - mass flux due to thermophoresis J - electrical current vector k - thermal conductivity L - characteristics length of plate xvi Le - Lewis number m - velocity stretching parameter Μ - mass M - mass generation rate Mn - magnetic parameter n - unit normal Nb - Brownian motion parameter Nr - bouyancy-ratio parameter Nt - thermophoresis parameter Nu - Nusselt number Pr - Prandtl number p - pressure q - energy flux qm - wall mass flux qw - wall heat flux Ra x - local Rayleigh number Re x - local Reynolds number S - surface Sh - local Sherwood number t - time T - fluid temperature Tw - temperature at the surface T∞ - ambient temperature U0 - constant u, v - velocity components along x- and y-axes uw - velocity of the stretching sheet vw - wall mass suction velocity V - arbitrary control volume x, y - Cartesian coordinates measured along the wall and normal to it, respectively xvii Greek Letters α - thermal diffusivity β - volumetric expansion coefficient of the nanofluid δ - boundary layer thickness η - similarity variable θ - dimensionless temperature µ - dynamic viscosity ν - kinematic viscosity ρf - fluid density ρp - nanoparticle mass density ( ρc) f - heat capacity of the fluid ( ρc) p - effective heat capacity of the nanoparticle material τ - stress vector τ - heat capacity ratio τw - wall shear stress φ - rescaled nanoparticle volume fraction ψ - stream function σ - electric conductivity of the fluid Subscripts w - condition at the surface ∞ - condition at ambient medium xviii LIST OF APPENDICES APPENDIX TITLE PAGE A Mathematical Formulation of the Natural Convective Boundary Layer Flow of a Nanofluid Past a Vertical Flat Plate 110 B Mathematical Formulation of the Forced Convective Boundary Layer Flow of a Nanofluid Past a Continuous Stretching Surface with Suction or Injection in the Presence of Magnetic Field 118 C Numerical Formulation of the Natural Convective Boundary Layer Flow of a Nanofluid Past a Vertical Flat Plate 127 D Numerical Formulation of the Forced Convective Boundary Layer Flow of a Nanofluid Past a Continuous Stretching Surface with Suction or Injection in the Presence of Magnetic Field 138 E The Matlab® Program for Natural Convective Boundary Layer Flow of a Nanofluid Past a Vertical Flat Plate 150 F The Matlab® Program for Forced Convective Boundary Layer Flow of a Nanofluid Past a Continuous Stretching Surface 154 G The Matlab® Program for Forced Convective Boundary Layer Flow of a Nanofluid Past a Continuous Stretching Surface with Suction or Injection in the Presence of Magnetic Field 158 H Academic Activities 163