Types of Heat Transfer Analysis
There are two types of heat transfer analyses based on interest in time.
Steady State
Thermal Analysis. In this type of analysis, we are only interested
in the thermal conditions of the body when it reaches a state of thermal
equilibrium. We are NOT interested in knowing the time it takes to reach
this state. At thermal equilibrium, the thermal energy entering each point
in the model is equal to the thermal energy leaving it. Generally, the
only material property that is needed for steady state analysis is the
thermal conductivity.
Transient Thermal
Analysis. In
this type of analysis, we are interested in knowing the thermal status
of the model as a function of time. A thermos designer, for example, knows
that the temperature of the fluid inside will eventually be equal to the
room temperature (steady state), but he or she is interested in finding
out the temperature of the fluid as a function of time. In specifying
material properties for transient thermal analysis, you need to specify
thermal conductivity, density, and specific heat. In addition, you need
to specify the initial temperatures, solution time, and time increment.
For transient studies, you can associate
heat flux and heat power conditions with a thermostat
defined by a temperature range at a specified location. For each time
step, the program turns the heat power
or heat flux condition on or off based
on the temperature at the thermostat location.