There are three main modes of heat transfer: conduction, convection, and radiation. Conduction involves the transfer of heat between objects in direct contact through kinetic energy of electrons. Convection refers to the transfer of heat by the mixing and movement of heated fluid particles. Radiation involves the transfer of heat through electromagnetic waves that does not require a medium and can travel through space.

1. Modes of heat transfer

2. What is heat transfer?
Heat transfer is the transfer
of energy from one
region to another as a
result of temperature
gradient(dT/dx).
Direction of heat transfer:
from higher temperature
to lower temperature.

3. modes of heat transfer
1. Conduction
2. Convection
3. radiation

4. Conduction
Conduction is the
transfer of heat from
one part of a
substance to another
part of substance or
any other substance
which is in contact
with it.

5. Conduction
Reason of heat transfer: increase in kinetic
energy of the free electrons of the matter.
Conduction in fluids is much easier due to
collision of molecules having high energy
to those having low energy.

6. convection
Convection is the
transfer of heat
within a fluid by
mixing of one
portion of fluid with
another.

7. convection
Reason for heat transfer: mixing of
fluid, so that heat exchange occur
from particles with higher
temperature to those with lower
temperature.
1. Free convection: mixing of fluid
occur naturally due to difference
in density of fluid that occur due
to having different temperatures.
2. Forced convection: mixing of fluid
occur using pumps or rotary
motion.

8. Radiation (electromagnetic
radiation)
Radiation is the
transfer of heat
through space or
matter by means of
other than
conduction or
convection.

9. Radiation (electromagnetic
radiation)
Heat travelling by radiation is
radiant heat.
It require no medium for
propagation, travels at light
speed, possess particular
wavelength, mostly invisible.
Its nature is same as an
electromagnetic wave or
light.

11. Thank you
reference: heat and mass transfer
by r k rajput , heat and mass
transfer by p k nag
-by somen

12. modes of heat transfer

13. modes of heat transfer
1. Conduction
2. Convection
3. radiation
Ppt in
description
Share to your friends who
need it.