COMSOL 6.2 - Thermal Mass

Thermal Mass

This feature models a node (one-port component) of the thermal system, at which a heat rate P is prescribed to take into account heat storage:

(6-21)

where C (SI unit: J/K) is the thermal capacitance, defined as

with V the volume (SI unit: m3), ρ the density (SI unit: kg/m3), Cp the heat capacity at constant pressure (SI unit: J/(kg·K)), and m the mass (SI unit: kg).

This component is similar to the Thermal Capacitor two-port component, with the difference that the thermal mass has a virtual fixed temperature node.

For a steady-state problem the temperature does not change with time and P = 0.

See Theory for the Thermal Capacitor and Thermal Mass Components for more details on the underlying theory.

Node Connections

Set the for the thermal mass node.

Node Parameters

The thermal capacitance used in Equation 6-21 should be set in this section.

Depending on the option selected in the list, different settings are required:

•

With (default), set directly a value or expression for C.

•

With , set values or expressions for the , V, the , ρ, and the , Cp. Select any material from the list to define the properties . For enter values or expressions.

•

With , set values or expressions for the , m, and the , Cp. Select any material from the list to define Cp . For enter a value or expression.

Initial Values

Set a user defined value or expression for the , Tinit, to be used at initialization, in particular to evaluate the heat storage term.

Results

Select appropriate options in the in order to include the following global variables (space-independent) in the default plots:

•

Location in User Interface

Context Menus

Ribbon

Physics tab with selected: