1. King Saud University dep Chemical Engineering College of Engineering ID: 426103592 Name: Mohammad.o. Dr : malik Al- ahmad Heat transfer by conduction

2. Contents:- 1)……. Modes of heat transfer. 2)……. Mechanisms of heat conduction. 3)……. Fourier Law of Heat Conduction. 4)……. Thermal Conductivities. 5)……. One –Dimensional, steady –state heat conduction:- -the plane wall. -the cylinder. -The sphere. -the composite wall.

3. Modes of heat transfer :- ((There are three fundamental types of heat transfer one of them is conduction.)) (1) Conduction:- ((Is the transfer of Heat from one part of a body to another part of the same body, Or from one body to another in physical contact with it,without appreciable displacement of the particles of the body.)) (1)

4. Mechanisms of heat conduction:- (( In a solid, the flow of heat by conduction is the result of the transfer of vibrational energy from one molecule to another. In fluids : it occurs in addition as a result of the transfer of kinetic energy. Heat transfer by conduction may also arise from the movement of free electrons, a process Which is particularly important with metals and accounts for their high thermal conductivities. It is need a medium to transfer, and moves from high region to low region.)) (2)

5. Fourier Law of Heat Conduction:- Q/A=-k*(dT/dx) heat flux thermal conductivity heat flux thermal conductivity This equation determines the heat flux vector q for a given temperature profile T and thermal conductivity k. The minus sign ensures that heat flows down the temperature gradientheat flux thermal conductivity

6. #Thermal Conductivities :- Thermal Conductivity k [J/(s-m-C)] SubstanceThermal Conductivity k [J/(s-m-C)] Substance 0.80 Glass 0.010 Syrofoam 1.1 Concrete 0.026 Air 79 Iron 0.040 Wool 240 Aluminum 0.15 Wood 420 Silver 0.20 Body fat 2450 Diamond 0.60 Water

7. #One –Dimensional, steady –state heat conduction:- -the plan wall. -the cylinder. -the sphere. -composite wall.

8. # the plane wall#

9. # The cylinder # A) One layer B) multilayer

10. # the sphere #

11. # the composite wall #

12. # Refrance # 1)R.H. Perry and C.H. Chiton, Eds, chemical engineering Hand book. 2)J.m.coulson and J.F.Richard son.eds, chemical engineering. (3)M.Necatiozisik, Heat transfer. (4)Incropera, Dewitt, Bergman, lavine, Fundamentals of Heat and Mass transfer, 5th edition.

13. The End