Heat and Mass Transfer

Course Objectives:
The objective of this course is to develop the knowledge about system, heat transfer processes and its application on thermal system. The subject also focuses on basic principles of heat transfer viz. conduction, convection and radiation. After completing the course, one is expected to have sound knowledge regarding heat transfer and its applications in industries

1. Conduction (4 hours)
1. Derivation of general three dimensional conduction equation in Cartesian coordinate, special cases
2. Discussion on 3-D conduction in cylindrical and spherical coordinate systems, no derivation
3. One dimensional conduction equations in rectangular, cylindrical and spherical coordinates for plane and composite walls
4. Overall heat transfer coefficient
5. Thermal contact resistance


2. Variable Thermal Conductivity (4 hours)
1. Derivation for heat flow and temperature distribution in plane wall
2. Critical thickness of insulation without heat generation
3. Thermal resistance concept & its importance
4. Heat transfer in extended surfaces of uniform cross-section without heat generation, Long fin, short fin with insulated tip and without insulated tip and fin connected between two heat sources
5. Fin efficiency and effectiveness
6. Numerical problems


3. One-Dimensional Transient Conduction (4 hours)
1. Conduction in solids with negligible internal temperature gradient (Lumped system analysis)
2. Use of Transient temperature charts (Heisler’s charts) for transient charts for transient conduction in semi-infinite solids
3. Numerical Problems
4. Finite Element Method (FEM) to solve one-dimensional Heat conduction problem


4. Concepts And Basic Relations In Boundary Layers (5 hours)
1. Flow over a body velocity boundary layer; critical Reynolds number; general expressions for drag coefficient and drag force; thermal boundary layer; general expression for local heat transfer coefficient
2. Average heat transfer Coefficient
3. Nusselt number
4. Flow inside a duct- velocity boundary layer, hydrodynamic entrance length and hydro dynamically developed flow; flow through tubes (internal flow)(discussion only)
5. Numericals based on empirical relation given in data handbook


5. Free Or Natural Convection (5 hours)
1. Application of dimensional analysis for free convection- physical
2. significance of Grash off number
3. Use of correlations of free convection in vertical, horizontal and inclined flat plates, vertical and horizontal cylinders and spheres
4. Numerical problems


6. Forced Convections (5 hours)
1. Applications of dimensional analysis for forced convection
2. Physical significance of Reynolds, Prandtl, Nusselt and Stanton numbers
3. Use of various correlations for hydro dynamically and thermally developed flows inside a duct, use of correlations for flow over a flat plate, over a cylinder and sphere
4. Numerical problems


7. Heat Exchangers (3 hours)
1. Classification of heat exchangers; overall heat transfer coefficient, fouling and fouling factor; LMTD
2. Effectiveness-NTU methods of analysis of heat exchangers
3. Numerical problems


8. Condensation And Boiling (5 hours)
1. Types of condensation (discussion only) Nusselt’s theory for laminar
2. condensation on a vertical flat surface
3. Use of correlations for condensation on vertical flat surfaces, horizontal tube and horizontal tube banks
4. Reynolds number for condensate flow; regimes of pool boiling, pool boiling correlations.
5. Numerical problems
6. 8Mass transfer definition and terms used in mass transfer analysis, Ficks First law of diffusion, and no numerical


9. Radiation Heat Transfer (5 hours)
1. Thermal radiation; definitions of various terms used in radiation heat transfer
2. Stefan-Boltzman law, Kirchoff’s law, Planck’s law and Wein’s displacement law
3. Radiation heat exchange between two parallel infinite black surfaces,
4. between two parallel infinite gray surfaces
5. Effect of radiation shield
6. Intensity of radiation and\solid angle
7. Lambert’s law; radiation heat exchange between two finite surfaces-
8. configuration factor or view factor
9. Numerical problems
10. Application of Heat Transfer
11. Electronic Cooling
12. Mechanical System Cooling


10. Introduction to Micro-Electronics Heat Transfer (2 hours)

Practical:

1. Temperature measurement by using different contact and non-contact type instruments.
2. Measurement of one-dimensional heat conduction.
3. Measurement of convection heat transfer using imperical formula.
4. Measurement of Radiation heat transfer.
5. Measurement of Nusselt number and Reynold number in condensation on horizontal tube.
6. Demonstration of CPU cooling.

References

1. Ozisik, “Heat transfer-A basic approach”, Tata Mc Graw Hill 2002
2. K. Nag, “Heat transfer”, Tata Mc Graw Hill 2002
3. K. Rajput, “Thermal Engineering”

Evaluation Scheme
The questions will cover all the chapters of the syllabus. The evaluation scheme will be as indicated in the table below: