Heat Transfer

1. HEAT
TRANSFER

2. WHAT IS HEAT TRANSFER?
Then….
• The transfer of heat is normally
from a high temperature object
to a lower temperature object.

3. What is heat?
These atoms are always in different types of motion (translation,
rotational, vibrational). The motion of atoms and molecules creates heat or
thermal energy.
This is a flash file made from a short molecular dynamics simulation
of water. The green lines represent hydrogen bonds between oxygen and
hydrogen. Notice the tight structure of water.
It is still possible to see all the motions the waters molecules have.
HOW HEAT IS BEING
TRANSFERRED?

4. WHAT IS TEMPERATURE?
Temperature is an average
value of energy for all the atoms
and molecules in a given system.

5. CONDUCTION--
- is the transfer of heat between substances that
are in direct contact with each other.
- Conduction occurs when a substance is heated,
particles will gain more energy, and vibrate
more.
HOW IS HEAT TRANSFERRED?

6. Conduction is the transfer of heat within a substance, molecule by molecule.

7. The measurement of how well a material can conduct
heat depends on how it's molecules are structurally
bonded together.

8. -Thermal energy is transferred from hot
places to cold places by convection.
-Water boiling in a pan is a good example
of these convection currents. Another
good example of convection is in the
atmosphere.
CONVECTION--

9. Convection is heat transfer by the mass movement
of a fluid in the vertical (up/down) direction. This
type of heat transfer takes place in liquids and gases.
This occurs naturally in our atmosphere.

10. - Heat can be transmitted though
empty space by thermal radiation
often called infrared radiation
RADIATION--

11. Radiation allows heat to be transfered through wave energy.
These waves are called Electromagnetic Waves, because the
energy travels in a combination of electric and magnetic
waves.

12. EMITTED RADIATION
CAN BE:
• Absorbed
- Increasing the internal energy of the gas molecules.
• Reflected
- Radiation is not absorbed or emitted from an
object but it reaches the object and is sent backward.
The Albedo represents the reflectivity of an object and
describes the percentage of light that is went back.

13. • Scattered
- Scattered light is deflected in all
directions, forward, backward, sideways. It is
also called diffused light.
• Transmitted
Radiation not absorbed, reflected, or
scattered by a gas, the radiation passes
through the gas unchanged.

14. - By transferring matter, energy—
including thermal energy—is
moved by the physical transfer of
a hot or cold object from one
place to another.
ADVECTION

15. Advection is the transfer of heat in the horizontal
(north/east/south/west) direction. In meteorology,
the wind transports heat by advection. This happens
all the time on Earth, heat is transported in many
ways.

16. IMAGE THAT SHOWS THE THREE
WAYS OF TRANSFERRING HEAT

17. 1.Define Energy.
2.What are its major
forms and give their
meanings.
Visit website: www.energy and its major forms.
ASSIGNMENT

18. THANK YOU FOR
LISTENING!!!
GODBLESS 