Engee documentation

Thermal Resistance

Constant thermal resistance in thermal systems.

blockType: AcausalFoundation.Thermal.Elements.Resistance

thermal resistance

Path in the library:

/Physical Modeling/Fundamental/Thermal/Elements/Thermal Resistance

Description

Block Thermal Resistance It is an abstract quantity that combines thermal conductivity, convection, and thermal radiation. Block Thermal Resistance It allows you to model heat transfer in a generalized form, regardless of whether it is carried out by thermal conduction, convection, radiation, or a combination of both.

Heat transfer equation for the unit Thermal Resistance:

where:

  • — thermal resistance;

  • — heat flow;

  • — the temperature difference between the layers.

Thermal resistance is related to other heat transfer values as follows:

where

  • — the distance between the layers, that is, the thickness of the material;

  • А — the cross-sectional area perpendicular to the direction of the heat flow;

  • — thermal conductivity of the material;

  • — coefficient of convective heat transfer;

  • — the radiation coefficient;

  • and — temperatures at ports A and B respectively.

Variables

Use the parameter group Initial Targets to set the priority and initial target values for the block parameter variables before modeling. For more information, see Configuring physical blocks using target values.

Ports

Conserving

# A — layer А
warm

Details

The thermal port corresponding to the layer А .

Program usage name

port_a

# B — layer
warm

Details

The thermal port corresponding to the layer .

Program usage name

port_b

Parameters

Parameters

# Thermal resistance — the value of thermal resistance
K/W

Details

The value of thermal resistance.

Units

K/W
Default value

1.0 K/W
Program usage name

resistance
Evaluatable

Yes

Examples