Thermal Capacitor

This feature models a two-port passive component of the thermal system. It connects two nodes, by creating a difference in the temperatures of its two connecting ports. It models heat storage in a domain.

It adds equations for the heat rates Pp1 and Pp2 and the temperatures Tp1 and Tp2 at the connecting ports p1 and p2 of the component, and defines the following relation between the heat rate P and the temperature difference ΔT:

(6-20)

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 volume (SI unit: J/(kg·K)), and m the mass (SI unit: kg).

For a steady-state problem the temperature difference 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.

Identifier

Enter a for the thermal capacitor. The prefix is C.

Node Connections

Set the two for the nodes connected by the thermal capacitor.

Component Parameters

The thermal capacitance used in Equation 6-20 should be set in this section.

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

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

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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.

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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 user defined values or expressions for the , T1,init, and the , T2,init, 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:

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Location in User Interface

Context Menus

Ribbon

Physics tab with selected: