Example27 Radiation Blocked by a Disc (Steady-state Analysis) -Simple Setting-

General

  • A disc is inserted in a space created by two plates.The heat radiation from a plate to the other is blocked by the disc.
    A problem similar to [Example 16: Radiation Blocked by a Disc (Steady-state Analysis) ] is set up in a simpler way.
    (Refer to the default setting of [Radiation: Equations and Setting Method.)
     

  • The temperature distribution and the heat flux vectors are solved.
     

  • Unless specified in the list below, the default conditions are applied.
     

 

Analysis Space

Item

Setting

Analysis Space

3D

Model Unit

mm

 

Analysis Condition

Item

Setting

Solver

Thermal analysis [Watt]

Analysis Type

Steady-state analysis

Analysis Options

None

 

Model

A disc is placed in between two plates.

The temperature of the bottom face of the lower plate is fixed at 1000[deg]. The natural convection and surface-to-surface radiation are set to the surroundings.

How the disc affects the radiation to the upper plate is analyzed.

Body Attributes and Materials

Body Number/Type

Body Attribute Name

Material Name

0/Solid

Plate_1

008_Cu

1/Solid

Disk

002_Polycarbonate(PC)

2/Solid

Plate_2

002_Polycarbonate(PC)

 

The emissivity of each body attribute surface is set as follows.

Body Attribute Name

Tab

Setting

Plate_1

Thermal Surface

Emissivity:
Select Specify on each body attribute

0.5

Plate_2

Thermal Surface

Emissivity:
Select Specify on each body attribute

0.5

Disk

Thermal Surface

Emissivity:
Select Specify on each body attribute

0.99

Boundary Condition

The boundary conditions are set as follows:

Boundary Condition Name/Topology

Tab

Boundary Condition Type

Setting

Outer Boundary Condition

Thermal

Heat Transfer: Convection

Natural convection (automatic calculation)

Radiation type: Surface-to-surface (accuracy prioritized)

HighTemperatureWall/Face

Thermal

Temperature

1000[deg]

Radiation type: Follow the outer boundary condition

0/Face

Thermal

Temperature

0[deg]

Radiation type: Surface-to-surface (accuracy prioritized)

 

The radiation setting can be done at [Thermal Analysis tab] > [Radiation Setting] dialog box as well.

Shown below are the setting details.

 

 

The outer boundaries of the three bodies are treated as surfaces for the surface-to-surface radiation. The emissivities for each body attribute is viewed.

 

By clicking [Show all boundary conditions set for the body attribute], the display is switched as shown below.

 

 

As set for each item, [0] for Disk and [High Temperature Wall] for Plate_1 are displayed.

[Follow the outer boundary condition] is set to each of them and [Surface-to-surface (accuracy prioritized)] is set as an outer boundary condition. It is confirmed that all surfaces are treated as those for the surface-to-surface radiation.

 

Results

The diagram below shows the temperature distribution of the upper plate.

(The body fields for the other bodies are hidden (right-click > hide body field).)

 

 

The center area is around 160[deg] whereas the other area is over 260[deg].

The disc is blocking the heat radiation.

 

The plot below indicates the temperature across the two points: (5, 0, 5) and (5, 10,5).