Heat transfer by radiation
The Radiative Heat Transfer block represents a heat transfer by radiation between two bodies. The transfer is governed by the Stefan-Boltzmann law and is described with the following equation:
|A||Emitting body surface area|
|TA, TB||Temperatures of the bodies|
The radiation coefficient is determined by geometrical shapes, dimensions, and surface emissivity. For example, the radiation constant for the heat transfer between two parallel plates is computed as
|ε1, ε2||Surface emissivity for the emitting and receiving plate, respectively|
Similarly, the radiation coefficient for concentric cylinders is determined with the formula
where r1 and r 2 are the emitting and receiving cylinder radii, respectively. Reference  contains formulas for a wide variety of shapes.
Connections A and B are thermal conserving ports associated with the emitting and receiving bodies, respectively. The block positive direction is from port A to port B. This means that the heat flow is positive if it flows from A to B.
Radiating body area of heat transfer. The default value is 0.0001 m^2.
Radiation coefficient of the two bodies, based on their geometrical shapes, dimensions, and surface emissivity. See  for more information. The default value is 4e-8 W/m^2/K^4.
The block has the following ports:
 Siegel, R. and J.R. Howell. Thermal Radiation Heat Transfer. New York: Taylor and Francis, 2002.