Geometry
Build up the geometry using a sector of a circle, three rectangles and a mirror plane.
Circle 1
1
In the Geometry toolbar, click  Circle.
2
In the Settings window for Circle, locate the Size and Shape section.
3
In the Radius text field, type r_outer.
4
In the Sector angle text field, type 90.
5
Locate the Position section. In the z text field, type length/2.
6
Click to expand the Layers section. In the table, enter the following settings:
Layer name
Thickness (m)
Layer 1
w_casing
Layer 2
w_wick
Rectangle 1
1
In the Geometry toolbar, click Rectangle.
2
In the Settings window for Rectangle, locate the Size and Shape section.
3
In the Width text field, type r_outer + w_contact.
4
In the Height text field, type l_heatsource.
5
Locate the Position section. In the z text field, type length/2-l_heatsource.
6
Click to expand the Layers section. In the table, enter the following settings:
Layer name
Thickness (m)
Layer 1
w_casing + w_contact
Layer 2
w_wick
7
Select the Layers to the right checkbox.
8
Clear the Layers on bottom checkbox.
Rectangle 2
1
In the Model Builder window, right-click Rectangle 1 and choose Duplicate.
2
In the Settings window for Rectangle, locate the Size and Shape section.
3
In the Width text field, type r_outer.
4
Locate the Position section. In the z text field, type length/2-l_heatsource*2.
5
Locate the Layers section. In the table, enter the following settings:
Layer name
Thickness (m)
Layer 1
w_casing
Layer 2
w_wick
Rectangle 3
1
Right-click Rectangle 2 and choose Duplicate.
2
Locate the Size and Shape section. In the Height text field, type length/2-l_heatsource*2
3
In the Settings window for Rectangle, locate the Position section.
4
In the z text field, type 0.
At this point, the geometry primitives for the upper half of the heat pipe has been added, go ahead and add a mirror plane to obtain a complete heat pipe.
Mirror 1
1
In the Geometry toolbar, click  Transforms and choose Mirror.
2
Click in the Graphics window and then press Ctrl+A to select all objects.
3
In the Settings window for Mirror, locate the Input section.
4
Select the Keep input objects checkbox.
5
Locate the Normal Vector to Line of Reflection section. In the r text field, type 0.
6
In the z text field, type 1.
7
In the Geometry toolbar, click  Build All Objects.
8
In the Graphics window, click  Zoom Extents.
Mesh Control Edges 1
1
In the Geometry toolbar, click  Virtual Operations and choose Mesh Control Edges.
We will use a quadrilateral mesh for the middle part of the heat pipe, and triangular mesh for the ends. To facilitate this mesh transition we define mesh control edges, which can be referenced during meshing, while not contributing to splitting of domains in other contexts.
2
In the Graphics window, select Boundaries 9, 13, 25, 29, 38, and 42 by clicking in accordance with the figure on the right. Verify that the selected edges match in the Settings window. In case of trouble, ensure sure that Activate Selection slider button is active (green).
Ignore Edges 1
1
In the Geometry toolbar, click  Virtual Operations and choose Ignore Edges.
Analogously, we want to ignore some other edges completely, not only during meshing.
2
With the Input selection active in Settings window for Ignore Edges, select Boundaries 5, 7, 11, 13, 17, 19, 23, and 24 in the Graphics window.
Ignore Edges 2
1
In the Geometry toolbar, click  Virtual Operations and choose Ignore Edges.
2
Select Boundaries 12, 14, 18, and 19.
3
In the Settings window for Ignore Edges, locate the Input section.
4
Clear the Ignore adjacent vertices checkbox.
Ignore Vertices 1
1
In the Geometry toolbar, click  Virtual Operations and choose Ignore Vertices.
2
Select Points 9, 10, 12, and 13.
3
In the Geometry toolbar, click  Build All.
It is a good practice to introduce explicit selections with descriptive names, these will help when making selections in the physics interfaces later on. Therefore, define selections for the three domains, and a handful of boundaries of interest.
Vapor Cavity
1
In the Geometry toolbar, click  Selections and choose Explicit Selection.
2
Select Domains 3 and 4.
3
In the Settings window for Explicit Selection, type Vapor Cavity in the Label text field.
Porous Copper Wick
1
In the Geometry toolbar, click  Selections and choose Explicit Selection.
2
Select Domains 2 and 5.
3
In the Settings window for Explicit Selection, type Porous Copper Wick in the Label text field.
Solid Copper Tube Casing
1
In the Geometry toolbar, click  Selections and choose Explicit Selection.
2
Select Domains 1 and 6.
3
In the Settings window for Explicit Selection, type Solid Copper Tube Casing in the Label text field.
Heat Sink
1
In the Geometry toolbar, click  Selections and choose Explicit Selection.
2
In the Settings window for Explicit Selection, type Heat Sink in the Label text field.
3
Locate the Entities to Select section. From the Geometric entity level list, choose Boundary.
4
Select Boundary 21.
Heat Source
1
In the Geometry toolbar, click  Selections and choose Explicit Selection.
2
In the Settings window for Explicit Selection, locate the Entities to Select section.
3
From the Geometric entity level list, choose Boundary.
4
Select Boundary 20.
5
In the Label text field, type Heat Source.
Cross Section of Cavity
1
In the Geometry toolbar, click  Selections and choose Explicit Selection.
2
In the Settings window for Explicit Selection, type Cross Section of Cavity in the Label text field.
3
Locate the Entities to Select section. From the Geometric entity level list, choose Boundary.
4
Select Boundary 5.
Cross Section of Wick
1
In the Geometry toolbar, click  Selections and choose Explicit Selection.
2
In the Settings window for Explicit Selection, type Cross Section of Wick in the Label text field.
3
Locate the Entities to Select section. From the Geometric entity level list, choose Boundary.
4
Select Boundary 10.
Cross Section of Casing
1
In the Geometry toolbar, click  Selections and choose Explicit Selection.
2
In the Settings window for Explicit Selection, type Cross Section of Casing in the Label text field.
3
Locate the Entities to Select section. From the Geometric entity level list, choose Boundary.
4
Select Boundary 13.
Inner Wick Boundary
1
In the Geometry toolbar, click  Selections and choose Explicit Selection.
2
In the Settings window for Explicit Selection, type Inner Wick Boundary in the Label text field.
3
Locate the Entities to Select section. From the Geometric entity level list, choose Boundary.
4
Select Boundaries 8 and 9.
All Wick Boundaries
1
In the Geometry toolbar, click  Selections and choose Explicit Selection.
2
In the Settings window for Explicit Selection, type All Wick Boundaries in the Label text field.
3
Locate the Entities to Select section. From the Geometric entity level list, choose Boundary.
4
Select Boundaries 8, 9, 11, and 12.
Next, a union selection of the cross sections is created. Those cross sections have no physical importance and will only be used for analysis in the postprocessing stage. Therefore, hide them during the setup of the model.
All Cross Sections
1
In the Geometry toolbar, click  Selections and choose Union Selection.
2
In the Settings window for Union Selection, type All Cross Sections in the Label text field.
3
Locate the Geometric Entity Level section. From the Level list, choose Boundary.
4
Locate the Input Entities section. Click  Add. Choose (holding the Ctrl key allows you to make multiple choices):
-
Cross Section of Cavity.
-
Cross Section of Wick.
-
Cross Section of Casing.
5
Click OK.
Hide for Geometry 1
1
In the Model Builder window, expand the Component 1 (comp1) > Definitions node.
2
Right-click View 1 and choose Hide for Geometry.
3
In the Settings window for Hide for Geometry, locate the Selection section.
4
From the Geometric entity level list, choose Boundary.
5
From the Selection list, choose All Cross Sections.