
19
2
Energy, Energy Transfer,
and Heat Transfer
What is heat? What do we mean by heat transfer? Heat transfer is probably one of
the most misunderstood engineering phrases. It is very important to understand that
there is no such physical entity as heat that is transferred from one point to another.
As we will see in this chapter heat transfer is simply one form of energy transfer.
Therefore, it is necessary to rst understand what energy and energy transfer are.
2.1 ENERGY AND WORK
After a few hours of hard work we feel exhausted and out of energy. On the other
hand, after a good rest we feel energetic and capable of doing work. It seems that ...