Example1 Microwave Oven

General

The heating of a piece of meat on the bone placed in a microwave oven is simulated.
It is solved by cascading the electromagnetic waves analysis and the thermal analysis.
Unless specified in the list below, the default conditions will be applied.

Analysis Space

Item	Settings
Analysis Space	3D
Model unit	mm

Analysis Conditions

Item	Settings
Solver	Electromagnetic Analysis [Hertz] Thermal Analysis [Watt]
Analysis Type	Electromagnetic waves analysis: Harmonics analysis Thermal analysis: Steady-state analysis
Options	Select “Ignore the influence of face/edge electrode thickness” *

* This is the default setting. There are no face electrodes with this model. Therefore it is irrelevant to select it or not.

Mesh tab, Harmonic analysis tab and Open boundary tab are set as follows.

Tabs	Setting Item	Settings
Mesh	Mesh Size	20
	Element type	2nd-order element
	Adaptive mesh	Off (to shorten the calculation time)
	Frequency-Dependent Meshing	Reference frequency: 2.45×10^9[Hz]
Harmonic analysis	Frequency	Minimum: 2.45×10^9[Hz] Maximum: 2.45×10^9[Hz]
Harmonic analysis	Input	10[W] *

* The power of actual microwave ovens is much higher than this.

The temperature distribution at steady state is analyzed in this exercise. Therefore, if the actual power is applied, the resulting temperature will be too high.

The input power is low to prevent it.

Model

A waveguide is placed on the top of a cavity box. An I/O port is set at the end of the waveguide.

The meat on the bone is placed on a plate. The temperature of the bottom face of CAVITY is 20[deg].

Body Attributes and Materials

Body Number/Type	Body Attribute Name	Material Name	Mesh Size
0/Solid	CAVITY	000_Air(*)
5/Solid	WAVEGUIDE	000_Air(*)
6/Sheet	Imprinting body
13/Solid	PLATE	PLATE	8
75/Solid	BONE	BONE	8
96/Solid	MEAT	WATER

* Available from the Material DB

Material Name	Tab	Properties
PLATE	Permittivity	Relative Permittivity: 7.0 tanD: 0.0
PLATE	Thermal Conductivity	1.5[W/m/deg]
BONE	Permittivity	Relative permittivity: 7.0 tanD: 0.1
BONE	Thermal Conductivity	1.5[W/m/deg]
WATER	Permittivity	Relative Permittivity: 76.7 tanD: 0.16
WATER	Thermal Conductivity	1.5[W/m/deg]

Boundary Conditions

Boundary Condition Name/Topology	Tab	Boundary Condition Type	Settings
PORT1/Face	Electric	I/O Port	Reference Impedance: Select “Use the characteristic impedance calculated from the port structure”.
EW/Face	Electric	Electric wall
20deg/Face	Electric	Electric wall
20deg/Face	Thermal	Temperature	20[deg]
Outer Boundary Condition	Electric	Electric wall

The default settings are “Magnetic wall” and “Adiabatic” for the electric and thermal boundary conditions respectively.

Results

The model is well heated overall.