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Home/Examples/Thermal Analysis [Watt]/Example 25: Periodic Boundary

Example 25: Periodic Boundary

General

The thermal analysis using the periodic boundaries is explained here.
The temperature distribution and the heat flux vectors are solved.
Unless specified in the list below, the default conditions will be applied.

Results will vary depending on Femtet version and the PC environment.

Analysis Conditions

Item	Settings
Solver	Thermal Analysis [Watt]
Analysis Space	3D
Analysis Type	Steady-state Analysis
Unit	mm
Analysis Options	None

Model

Body Attributes and Materials

Body Number/Type	Body Attribute Name	Material Name	Mesh Size
0/Solid	SUB	006_Glass_epoxy *1
1/Solid	GND	008_Cu *1
2/Solid	MAINCHIP	001_Alumina *2
3/Solid	SUBCHIP	001_Alumina *2
4/Solid	HOLE	008_Cu *1	0.5
5/Solid	HOLE	008_Cu *1	0.5
6/Solid	HOLE	008_Cu *1	0.5
7/Solid	HOLE	008_Cu *1	0.5
8/Solid	HOLE	008_Cu *1	0.5
9/Solid	HOLE	008_Cu *1	0.5
10/Solid	HOLE	008_Cu *1	0.5
11/Solid	HOLE	008_Cu *1	0.5

*1 Available from the material DB.

Boundary Condition

Boundary Condition Name/Topology	Tab	Boundary Condition Type	Setting
Outer Boundary Condition	Thermal	Heat Transfer: Convection	Natural Convection (Automatic Coefficient Calculation) Room Temperature: 25 [deg]
t40	Thermal	Temperature	40 [deg]
Periodic1	Symmetry/Continuity	Periodic
Periodic2	Symmetry/Continuity	Periodic

“Periodic1” and “Periodic2” are set to be a periodic boundary pair.

Select [Natural Convection (Automatic Coefficient Calculation)] on the outer boundary condition.

* The correction coefficient for the natural convection is calculated automatically. See [Heat Transfer: Ambient Radiation] for more information.

Results

The temperature diagram is shown as below.

You can see the temperature is the same on the faces with periodic boundaries.