Face to Face Thermal Link with the Thermal Link Wizard

Transcription

1 SECTION 1 Face to Face Thermal Link with the 1 SECTION 1 Face to Face Thermal Link with the Thermal Link Wizard The following is a list of files that will be needed for this tutorial. They can be found in the Thermal_Link_Wizard folder. pipe_hanger_begin.tdf Overview Face to Face conduction allows us to quickly mesh the individual parts in a CAD program and then easily connect them thermally without further mesh editing. The purpose of this tutorial is to understand how Face to Face conduction is setup and executed. Face to Face conduction allows parts with disconnected meshes to be thermally connected and supports contact resistance. In this example, we are simulating a pipe hanger clamped around a duct carrying hot gas inside. Face to Face conduction will be setup to enable conduction from the pipe to the pipe clamp, and once again from the clamp to the hanger strap. The Thermal Link Wizard is used to identify and select potential links within the model

2 2 Training Manual Select File 1. Select the menu item File > Open. Choose the file named pipe_hanger_begin.tdf. Click the [Open] button Thermal Links 2. Select the menu item Edit > Thermal Links. The Thermal Link Properties dialog box appears. 3. Select the [Thermal Link Wizard...] button to open the Thermal Link Wizard dialog box.

3 SECTION 1 Face to Face Thermal Link with the 3 The Thermal Link Wizard is used to determine and add links. A threshold distance is used to determine candidate links. Any parts showing in the graphics interface are used to determine links

4 4 Training Manual Each part looks for other parts within the threshold distance and a list of candidate links is generated. The wizard also looks at which side of the element is the likely candidate to be linked. 4. Make sure Allow Links to the Same Part is not checked. In this case no links should be created linking a part to itself. If this is checked your candidate list may be much longer than necessary. 5. Assign a Threshold value of 10 mm. 6. Select the [Determine Candidate Links] button to populate the Candidate Link list. 7. Check the Selection Updates Graphics checkbox. This will update the graphics to show the selected thermal link.

5 SECTION 1 Face to Face Thermal Link with the 5 8. Select the first thermal link candidate in the list. Rotate the model to view the shaded link. (It may help to turn off the mesh [CTRL-M]). With the thermal link candidate selected the two linked parts will stay solid and all other parts will become transparent. The elements that are linked show up as dark blue, the non-linked side of the element shows up as red. You also have the option of isolating the linked parts, to only show the parts that are linked, and Auto-Center Geometry, which will auto-center on the two linked parts. Try toggling on and off these check boxes as you click through your list of candidate links. 9. Find the link between Hot Fluid Duct and Bottom_Hangar_Part_ A (shown above). 10. Select the checkbox next to the link in the Define column. 11. Identify and check Define for the three remaining links that are necessary to link the two remaining hangers to the duct and the hanger strap to the top hanger. 12. Select the [Add Defined] button to create the thermal links; this will add the links to the Thermal Links Properties window. 13. You can now close the Thermal Link Wizard. 14. Check the box for Selection Updates Graphics. 15. Select the link in the Thermal Link Properties window between the Hot Fluid Duct and Bottom_Hangar_Part_A

6 6 Training Manual 16. Confirm that the wizard selected the front face for both parts. 17. Set the Offset Distance to 4 mm. 18. Set the Contact Resistance to m 2 -K/W. 19. Confirm in the graphics window that there is a link between the two parts (linked elements will appear red/blue as in the wizard).

7 SECTION 1 Face to Face Thermal Link with the The following table lists the rest of the thermal links. Setup the Offset Distance and confirm that the links are set up correctly. Table 1: Thermal Links Part Name #1 Part Name #2 Contact Resistance Offset Distance Hot Fluid Duct Top_Hangar_Casting 0.001m 2 K/W 4 mm Top_Hangar_Casting Hangar_Strap m 2 K/W 1 mm Hot Fluid Duct Bottom_Hanger_Part_B m 2 K/W 4 mm 21. Click the [OK] button when finished. 22. Select the File > Save As. Save the file as pipe_hanger_completed.tdf. Click the [Save] button Run Model 23. Select the Analyze Tab > Results Tab. Click the [Run] button. 24. Select the Post Process Tab > Results sub-tab. Select any element on the model to view the temperature results. 25. Click the [Auto Scale] button below the graphics window

8 8 Training Manual 26. Click the Magnify button in the toolbar located at the top of the screen. Left-click and drag a box around the top part of the object. 27. Click the Zoom button in the toolbar located at the top of the screen. Zoom out so the full object can be seen by holding down the right mouse button and dragging to the right or left.

9 SECTION 1 Face to Face Thermal Link with the Zoom into the bottom of the object to view results. 29. Click the [Part Select] button in the toolbar. Select the bottom bracket by clicking on it. 30. Select the Post Process Tab > Results sub-tab to view the part average temperature. 31. Select the Post Process Tab > Plot/Export sub-tab

10 10 Training Manual 32. Click the [Element] select button in the toolbar. Select several elements on the bottom bracket. The thermal nodes will be added to the plot list. 33. In the Format section at the bottom of the window, select the {Spatial Plot} radio button.

11 SECTION 1 Face to Face Thermal Link with the Click the [Plot] button. A graph of the temperatures appears. This plot shows the distribution of temperatures of the thermal nodes in the plot list. 35. Click the [Close] button to close the graph

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