CAE Fidesys 9.0 Documentation

Setting Heat Transfer (3D, Working With Two Blocks)

We solve the 3D problem of a hollow two-material cylinder the inner and outer surfaces of which undergo convection.

The pictures represent a geometric model of the problem.

The inner radius of the cylinder R_i = 0.30 m, the middle radius of the cylinder (at the place of material changing) R_m = 0.35 m, the external radius of the cylinder R_e = 0.37 m.

Сonvective heat exchange with internal temperature T_i = 70 ° C and coefficient h_i = 150 W/ m²/°C occurs on the inner surface of the cylinder. Сonvective heat exchange with exterior temperature T_e = -15 °C and coefficient h_e = 200 W/ m²/°C occurs on the outer surface of the cylinder.

Materials are isotropic. The material heat transfer 1 is Ѵ₁ = 40 W/(m·°C). The material heat transfer 2 is Ѵ₂ = 20 W/(m·°C).

Test pass criterion is the following:

at the point (0.3, 0, 0) heat flux 6687 W/ m² is within 1%.

Geometry creation

1. Create the first cylinder.

On the command bar, select the module for constructing volume geometry (Mode – Geometry, Entity – Volume, Action – Create).

Select Cylinder in the list of geometric elements.

Specify the cylinder dimensions:

• Height: 0.01;
• Circular;
• Radius: 0.3.

Click Apply.

2. Create the second cylinder.

On the command bar, select the module for constructing volume geometry (Mode — Geometry, Entity — Volume, Action — Create). Select Cylinder in the list of geometric elements.

Specify the cylinder dimensions:

• Height: 0.01;
• Circular;
• Radius: 0.35.

Click Apply.

3. Create the third cylinder.

On the command bar, select the module for constructing volume geometry (Mode — Geometry, Entity — Volume, Action — Create). Select Cylinder in the list of geometric elements.

Specify the cylinder dimensions:

• Height: 0.01;
• Circular;
• Radius: 0.37.

Click Apply.

As a result, three generated entities are displayed in the Model Tree (Volume 1, Volume 2 and Volume 3).

4. Subtract the first cylinder from the second one.

On the command bar, select the module for constructing volume geometry (Mode — Geometry, Entity — Volume, Action — Boolean).

Select Subtract in the list of operations.

Set the following parameters:

• A Volume ID(s): 2 (volumes from which other volumes will be subtracted);
• B Volume ID(s): 1 (the volumes to be subtracted);
• Keep Originals.

Click Apply.

5. Subtract the second cylinder from the third one.

On the command bar, select the module for constructing volume geometry (Mode — Geometry, Entity — Volume, Action — Boolean). Select Subtract in the list of operations.  

Set the following parameters:

• A Volume ID(s): 3 (volumes from which other volumes will be subtracted);
• B Volume ID(s): 2 (the volumes to be subtracted);
• Keep Originals.

Click Apply.

As a result, five generated entities are displayed in the Model Tree: Volume 1, Volume 2, Volume 3, Volume 4 and Volume 5. Delete the thirst three bodies by right-clicking and selecting Delete.

Two entities: Volume 4 and Volume 5 are left in the Model Tree.

6. Merge obtained entities.

On the command bar, select the module for constructing volume geometry (Mode — Geometry, Entity — Volume, Action — Imprint and Merge).

Select Merge Volumes in the list of operations.

Set the following parameters:

• Volume ID(s): 4 5 (the volumes to be united).

Click Apply.

Meshing

1. On the command bar, select the mesh module (Mode — Mesh, Entity — Curve, Action — Mesh).

Specify the parameters of mesh refinement:

• Select Curves: all (mesh will be create on all the curves);
• Select the way of meshing: Equal;
• Select the meshing parameters: Interval;
• Interval: 200.

Click Apply Size.

2. On the command bar, select the volume mesh module (Mode — Mesh, Entity — Volume, Action — Mesh).

Specify the mesh refinement level:

• Select meshing scheme: Polyhedron;
• Select Volumes: all (mesh will be create on all the volumes).

Click Apply Scheme.

Click Mesh.

Setting material and block properties

1. Create Material 1.

In the command bar, select the module for specifying material properties (Mode — Blocks, Entity — Materials Management).

Specify the name of the material. Material 1. Drag from the left column to the section Thermal of the label Thermal isotropic in the Material Properties column.

Set the following parameters:

• Thermal conductivity coefficient: 40.

Click Apply.

2. Create Material 2.

Select setting the material properties section on Command Panel (Mode — Blocks, Entity — Materials Management).

Specify the name of the material. Material 2. Drag from the left column to the section Thermal of the label Thermal isotropic in the Material Properties column.

Set the following parameters:

• Thermal conductivity coefficient: 20.

Click Apply.

Close the Materials management window.

3. Create Block 1.

On the command bar, select the block management module (Mode — Blocks, Entity — Block, Action — Add).

Set the following parameters:

• Block ID: 1;
• Entity List: Volume;
• Entity ID(s): 4.

Click Apply.

4. Create Block 2.

On the command bar, select the block management module (Mode — Blocks, Entity — Block, Action — Add).

Set the following parameters:

• Block ID: 2;
• Entity list: Volume;
• Entity ID(s): 5.

Click Apply.

5. Set parameters for block № 1.

On the command bar, select the block management module (Mode - Blocks, Entity - Block, Action - Block properties/parameters).

Set the following parameters:

• Block ID(s): 1;

• Category: Solid;

• Material: Material 1;

• Coordinate System: Global Cartesian;

• Order: 1.

Click Apply.

6. Set parameters for block № 2.

On the command bar, select the block management module (Mode - Blocks, Entity - Block, Action - Block properties/parameters).

Set the following parameters:

• Block ID(s): 2;

• Category: Solid;

• Material: Material 2;

• Coordinate System: Global Cartesian;

• Order: 1.

Click Apply.

Setting boundary conditions

1. Set the process of convective heat exchange on the inner surface of the cylinder.

On the command panel, select the boundary conditions module (Mode — Boundary Conditions, Entity — Convection, Action — Create).

Set the following parameters:

• Entity List: Surface;

• Entity ID(s): 10;

• Select the way of parameters setting: Surrounding;

• Temperature: 70;

• Coefficient: 150.

Click Apply.

2. Set the process of convective heat exchange on the outer surface of the cylinder.

On the command panel, select the boundary conditions module (Mode — Boundary Conditions, Entity — Convection, Action — Create).

Set the following parameters:

• Entity List: Surface;

• Entity ID(s): 15;

• Select the way of parameters setting: Surrounding;

• Temperature: -15;

• Coefficient: 200.

Click Apply.

3. Fix the base of the cylinder.

On the command panel, select the boundary conditions module (Mode — Boundary Conditions, Entity — Displacement, Action — Create).

Set the following parameters:

• Entity List: Surface;

• Entity ID(s): 12 13 16 17 (using space after each of them);

• Degrees of Freedom: Z.

Click Apply.

Starting calculation

1. Set the type of the problem to be solved.

On the command bar, select the calculation settings module (Mode — Calculation Settings, Calculation Settings — Static, Static — General).

Set the solver settings:

• Dimensions: 3D;

• Model: Elasticity

• Model: Heat Transfer.

Click Apply.

2. In a pop-up window select a folder to save the result and enter the file name.

3. In the case of a successful calculation, the console displays the message: Calculation finished successfully at "date" "time".

Results analysis

1. Open the file with the results. There are three ways to do that.

• Click Ctrl+E.

• From the main menu, select Calculation. Click Open Results.

• Select Results on Command Panel (Mode - Results). Click Open results.

2. Display the component of the heat flux.

In FidesysViewer window set the following parameters on Toolbar:

• Representation Field: Heat Flux;

• Representation Mode: Surface.

To display the color legend scale, click the button Toggle Color Legend Visibility on Command Panel.

3. Select a point where you need to view the heat flux.

In the Main Menu, select the filter Probe Location. In the tab Properties set the coordinates of the point A where you need to view the stress:

• Show Sphere;

• Center: 0.3 0 0;

• Radius: 0;

• Number Of Points: 1.

Click Apply.

To apply all of the filters changes automatically, click Apply changes to parameters automatically on Command Panel.

As a result, point A is displayed at the picture.

4. View a numerical value of the heat flux  at the selected point A.

See the heat flux values in the line Heat Flux in the tab Information in the field Data Arrays.

The heat flux value is calculated using the following formula:

The difference between the obtained value 6686.41 and the required one 6 687 is 0.01%.

5. Download numerical data.

Select File  Save Data in the Main Menu or click Ctrl+S. Enter the file name (*.csv format), leave it by default. Click ОК. The saved file is an ordinary table of numerical data which can be opened in any text editor.

Using Console Interface

Geometry creating, meshing, setting boundary conditions and materials can be performed using the console interface. Below is a link to the program code that allows you to perform the steps described above manual, you only need to specify the full path and name.

thermal_conductivity