CONVECTION

1) Convection heat transfer involves both energy transfer due to random molecular motions and by bulk motion of the fluid molecular motions and by bulk motion of the fluid

a) Convection heat transfer includes both forced convection and natural convection

b) The rate of convection heat transfer is observed to be proportional to the temperature difference, and is conveniently expressed by Newton’s law of cooling as

Where h is the convection heat transfer coefficient in A is the surface area through which convection heat transfer takes place, T_s is the surface temperature, and T_∞ is the temperature of the fluid sufficiently far from the surface. Note that at the surface, the fluid temperature equals the surface temperature of the solid

c) The convection heat transfer coefficient h is not a property of the fluid.