This example shows the usage of thermal blocks for developing a model of a long iron rod that is heated with a heat source through its left face. The right face and the outer cylindrical surface are open to atmosphere, with a force heat convection.
The rod is made of iron (specific heat is 447 J/(kg*K), thermal conductivity is 80.2 W/(m*K)), has 20 cm in length and 2.25 cm in diameter.
The example has two thermal models of the rod: the first one is called Segmented block and the second one is called Lumped block. The Segmented block model represents the rod as a set of 20 segments connected in series, each of which has 1/20-th of the overall thermal mass, heat conductance, and heat convection. In the Lumped block model all the thermal properties are supposed to be lumped into a single thermal mass, single heat convection, and two equally divided heat conductances.
For the sake of convenience, the temperature of every fifth element in the segmented block is monitored and plotted together with the temperature measured in the lumped model. The graph shows the temperature distribution along the rod and the temperature of the lumped block.