Heat and Mass Transfer

Syllabus

1. Conduction (15 hours)
   1. Modes of heat transfer
   2. Fourier's law and thermal conductivity
   3. Differential equations of heat conduction, boundary conditions and its solution
   4. One-dimensional steady state condition without heat generation: plane wall, cylinder, sphere
   5. Concept of thermal resistance, overall heat transfer coefficient
   6. Critical radius, variable thermal conductivity
   7. One-dimensional steady state condition with heat generation
   8. Two-dimensional steady state condition
   9. Transient conduction: lumped capacitance model, transient problems and analytical solutions, application of Heisler charts
   10. Numerical methods in conduction: steady state one and two-dimensional problems, one-dimensional transient problem for explicit and implicit cases
2. Convection (10 hours)
   1. Boundary layer concepts
   2. Natural convection: concept and governing equations, applications for vertical and horizontal plate, applications in a horizontal cylinder
   3. Forced convection: implications of dimensionless numbers, laminar flow heat transfer in circular pipe and flat plate, turbulent flow heat transfer in circular pipe and pipes of other cross section, heat transfer across a cylinder and sphere, heat transfer across banks of tubes
3. Radiation (7 hours)
   1. Definitions and concept of spectrum
   2. Laws of radiation: black body radiation, Stefan Boltzmann law, Planck's law, Wien's displacement law, Lambert cosine law
   3. Radiation exchange between black surfaces
   4. Applications of shape factor
   5. Radiation exchange between grey surfaces (radiosity-irradiation method)
   6. Gas radiation
   7. Concept and applications of radiation shield
4. Applications of Heat Transfer (7 hours)
   1. Fins: types and applications, heat dissipations from fins, fin performance (fin effectiveness and fin efficiency)
   2. Heat exchangers: types, LMTD method (parallel, counter-flow), effectiveness, NTU method (parallel, counter-flow), overall heat transfer coefficient, fouling factors
5. Condensation and Boiling (2 hours)
   1. Boiling heat transfer
   2. Pool boiling and flow boiling
   3. Correlations in boiling
   4. Condensation heat transfer
   5. Nusselt's theory of condensation
   6. Correlations in condensation
6. Mass Transfer (4 hours)
   1. Basic concepts
   2. Diffusion mass transfer
   3. Fick's law of diffusion
   4. Steady state molecular diffusion
   5. Convective mass transfer
   6. Momentum, heat and mass transfer analogy
   7. Convective mass transfer correlations
   8. Limitations of heat and mass transfer analogy

Practicals

1. Comparison between thermal conductivities of different types of materials
2. Investigation of temperature distribution along the extended surface
3. Free and forced convection
4. Determination of LMTD and heat transfer in parallel flow and counter flow
5. Calculation of emissivity of grey body
6. Calculation of heat transfer during boiling
7. Calculation of mass and energy balance in a cooling tower
8. Steady and unsteady state heat conduction simulation using open-source software

Evaluation

Final exam questions cover all chapters. Approximate marks distribution (total 60 marks over 45 hours):

1. Conduction: 16 marks
2. Convection: 12 marks
3. Radiation: 10 marks
4. Applications of Heat Transfer: 10 marks
5. Condensation and Boiling: 4 marks
6. Mass Transfer: 8 marks