Module Notes
Heat Transfer
This module will not be offered for this semester
Module Details
The ability to comprehend the basic principles and modes of heat transfer and the physical significance and importance of the relevant dimensionless numbers for solving heat transfer problems.
The ability to develop microscopic and macroscopic heat transfer balances in steady and transient state.
Understand how to simplify practical and complicated heat transfer problems and solve them primarily analytically, but also by using appropriate numerical methods
Understand how to simplify complex heat transfer phenomena to simpler ones, to develop and simplify heat flow balances, to determine suitable auxiliary conditions and solve the final equations.
Understand the difference between heat conduction, convection (forced & free) and radiation. The required in each case assumptions and the procedure to solve the corresponding problems.
Course Codes: CHM_102, CHM_201, CHM_300, CHM_402, CHM_130, CHM_230, CHM_220, CHM_320, CHM_550
INTRODUCTION. Mechanisms of heat transfer, examples. Fourier’s law for heat conduction, Newton correlation in heat convection. General differential equation for heat transfer. Boundary and initial conditions in heat transfer problems. The Biot number.
STEADY 1D HEAT CONDUCTION. Heat generation in the bulk and on material interfaces. Addition of heat resistances in various geometries. The fin approximation.
STEADY HEAT CONDUCTION IN 2D. Exact solutions via separation of variables. Shape factor. Solution using charts and polynomial approximations.
TRANSIENT HEAT CONDUCTION IN ONE OR MORE DIMENSIONS. The similarity method. Solution using separation of variables. Approximate solutions.
INTRODUCTION TO HEAT CONVECTION. Forced and free convection. Dimensionless analysis and similarity. Examples admitting simple analytical solution. Approximate correlations in heat convection. Analogies between heat, mass and momentum transfer. The Nusselt, Graetz, Prandtl and Peclet numbers.
FORCED CONVECTION INSIDE DUCTS AND AROUND BODIES. Convection over a surface, the boundary layer in heat transfer. Entrance length in ducts. Developing and developed flow with respect to hydraulic and heat characteristics. Using polynomials to obtain approximate solutions. Correlations and diagrams to solve problems. Convection in turbulent flow.
FREE CONVECTION. Free convection around bodies. Coupled free and forced convection. The Grashof and Rayleigh numbers.
HEAT RADIATION. Radiation intensity. Radiation formula by PLANCK. Law by STEFAN-BOLTZMANN. Radiation and absorption. The black and brown body. Radiation between brown bodies. Gas radiation.
Teaching Organization
LECTURES: 3 h/w
RECITATION: 2 h/w
PROJECT/HOMEWORK: 26/semester
Total Module Workload (ECTS Standards):
Written Examination
A final exam is given in the end of the sementer. It covers the most important topics of the module via two or three problems, which have prespecified weights. The exam is graded by the Lecturer. In the past an optional mid-term exam was given, but less than 25% of the students participated.
Course Book
“Μεταφορά θερμότητας και Μάζας”, Ασημακόπουλος, Λυγερού, Αραμπατζής. Εκδ. Παπασωτηρίου, 2012
Additional Literature
- “Heat Transfer”, 7th Ed., Holman, 1990, McGraw Hill
- “Transport Phenomena”, Revised 2nd Ed., Bird, Stewart, Lightfoot, 2007, Wiley
- “Fundamentals of Momentum, Heat & Mass Transfer”, Welty, Wicks, Wilson, 1984, Wiley.
- “Fundamental Principles of Heat Transfer”, Whitaker S., 1977, Krieger
- “Αρχές μεταφοράς θερμότητας & μάζας”, Κακάτσιος, Εκδ. Συμεών, 2006
- “Fundamentals of Transport Phenomena”, Fahien R.W., 1983, McGraw Hill