This information is part of the Modelica Standard Library maintained by the Modelica Association.

This is a model for transport of heat without storing it; see also: ThermalResistor. It may be used for complicated geometries where the thermal conductance G (= inverse of thermal resistance) is determined by measurements and is assumed to be constant over the range of operations. If the component consists mainly of one type of material and a regular geometry, it may be calculated, e.g., with one of the following equations:

• Conductance for a box geometry under the assumption that heat flows along the box length:

  G = k*A/L
  k: Thermal conductivity (material constant)
  A: Area of box
  L: Length of box
      

• Conductance for a cylindrical geometry under the assumption that heat flows from the inside to the outside radius of the cylinder:

  G = 2*pi*k*L/log(r_out/r_in)
  pi   : Modelica.Constants.pi
  k    : Thermal conductivity (material constant)
  L    : Length of cylinder
  log  : Modelica.Math.log;
  r_out: Outer radius of cylinder
  r_in : Inner radius of cylinder
      

Typical values for k at 20 degC in W/(m.K):
  aluminium   220
  concrete      1
  copper      384
  iron         74
  silver      407
  steel        45 .. 15 (V2A)
  wood         0.1 ... 0.2