Week 5.3 - Electronic Enclosure

Cleaning up the Powerboard assembly geometry by creating the workflow in ANSYS Workbench Part - 2:

Objective: The idea behind the challenge is to learn how to import the CAD model into SpaceClaim then do necessary improvements so that Icepak can accept all the parts into its module to further work on thermal and flow simulations. For now, we have taken a Power Board assembly to work on it.

Introduction:

ANSYS Workbench platform is the backbone for delivering a comprehensive and integrated simulation. It is used to perform various types of structural, thermal, fluid, and electromagnetic analyses. The entire simulation process is tied together by a project schematic, from which you can interact with applications that are native to ANSYS Workbench or launch applications that are data-integrated with ANSYS Workbench. It includes CAD connectivity, automated meshing, a project-level update mechanism, optimization tools, DOE.

ANSYS Workbench is a project-management tool. It can be considered as the top-level interface linking all our software tools. Workbench handles the passing of data between ANSYS Geometry / Mesh / Solver / Postprocessing tools. This greatly helps project management. You do not need to worry about the individual files on disk (geometry, mesh, etc). Graphically, you can see at-a-glance how a project has been built.

It is easy to see at a glance how a model has been built, and determine which files were used for a particular simulation (pairing geometry files to solver runs). Workbench also makes it straightforward to perform parametric analyses (without the user needing to manually launch each application in turn), and makes it easy to simulate multi-physics scenarios like fluid-structure interaction.

• Ansys Workbench uses the two types of CAD models, one is a design modeler and the other is SpaceClaim.
• Engineers in nowadays are mostly using the SpaceClaim because of the flexibility, compatibility, and having better and more handling options for the geometry.
• While a geometry or CAD file coming from a design section to the analysis section, it needs a lot of repair and modifications.

1. Use space claim commands to defeature the enclosure:

SpaceClaim:

ANSYS SpaceClaim enables anyone to create, edit, or repair geometry without worrying about the underlying technology. With SpaceClaim, working with 3D modeling software becomes fast, easy, flexible, and rewarding, no matter where in the workflow you need it.

Users of ANSYS SpaceClaim can:

• Edit, repair, and create any geometry - without worrying about where the file comes from.
• Increase productivity by removing the CAD bottleneck in your workflow.
• Manipulate geometry faster, easier, and more intuitively resulting in less time spent struggling with geometry and more time dedicated to primary job functions such as manufacturing, analysis, and concept modeling.

The given geometry file of power board assembly is given in .stp file which is readable by the SpaceClaim.

• We have no use with the enclosure in the thermal or flow simulation.
• So, for that reason, we did not consider the enclosure component.
• The CAD model without the enclosure component looks like:

2. Use Icepack commands to convert CAD shapes into Icepak primitive shapes:

• We need to change the CAD model (parts) into the ICE PAK components in the SpaceClaim.
• To do that, we need to go to "Workbench" which is located in the toolbar in SpaceClaim.

• After entering into the workbench module, Select the Identify Object.
• We firstly identify the 30 objects. Those are:

• Components that are in red color are the identified objects by the Icepak. Rest are all unidentified objects.
• But we can still see that some parts are not identified because of different reasons. So, we need to Convert these parts into ICEPAK objects by selecting the "ICEPAK Simplify" option. Before that, we need to confirm the parts identified by the ICEPAK.
• For that, we need to click on the "Show" option.

• Then click on ICEPAK bodies.
• Now, we only come to see Non-Icepak bodies. For them, we need to convert into the Icepak bodies.

• For that, We need to click on the "Icepak Simplify" option, then need to give a suitable simplification type.
• There are four types of the simplification process. They are 1) Level 0 (bounding box) 2) Level 1 (cuboid, cylinder fit) 3) Level 2 (polygon fit) 4) Level 3 (CAD object).

Level 0:

• Whenever the object is unidentified by the Icepak, we need to simplify it by using a suitable level of simplification.
• So, here the Level 0, it converts the geometry of the part to a bounding box.
• The actual fig is:

• Level 0 looks like:

Level 1:

• It converts the geometry part into the cuboid or cylinder fit model.
• Here at this level, it converts the geometry into many parts. So, that Icepak identifies the geometry simply.

Level 2:

• Here in this level, the same as level 1, it converts the geometry into many parts.
• But it converts the geometry into the polygonal fit, which is more suitable for the flow and thermal simulations.
• In this level, the curves and radians are maintained.

Level 3:

• This level provides the meshing feature to the level 2 object. This level is called a CAD object.

• Fan component with the level 3 simplification type.

• The heat sink is provided with the level 1 specification type because it does not have any curve and curvature sides. So level 1 preferred the heat sink.

• After applying suitable levels to the unidentified objects, All are get's identified and looked like:

3. Save converted geometry

• The above figure is the total enclosure of power board assembly with parts including in it.
• Now after converting all the parts of power board assembly into Icepak objects, we need to convert and save this file in the Icepak format for further simulation in the Icepak Module.
• For that, we need to save this file in the "Icepak Project(*.icepakmodel)" format.

• After saving the project in the Icepak format, now exit or close the SpaceClaim module.
• Now unpack the saved file in the Icepak module.

4. Open saved converted model into Icepak:

• After opening the Icepak module, the saved file is automatically imported into the Icepak module.
• This action is because the geometry file is connected directly to the setup file of the Icepak module.

• The above figure is the tree diagram of the Powerboard assembly that we have made changes and imported it into the Icepak module.
• If we expand that tree one by one, we come to see the geometry components one by one. Like:
• It is a solid mesh which we did not use in the flow or thermal simulation. So we make it inactive from the components list.

• After removing the enclosure, the CAD model looks like:

5. Check the geometry in Icepak:

• We need to check all the items or parts we are identified, simplified, and converted are imported or not.
• This can be known by just checking the tree components provided by the Icepak module in the toolbox.
• Once we expanded all the tree components in the module, we can see the final Wired geometry. That looks like:

6. Modify components in Icepak in order to define the correct physics:

• Modifying components from the original CAD model is a very useful process in the Icepak.
• Because sometimes, the geometry may have openings (not connected to other components), may have overlapping of the components, deleting some very small components from geometry that may give you difficulty and have no use in the flow or thermal simulations, etc.
• The presence of these may cause uncertainties in the mesh formation. An unstructured mesh with no proper nodal attachments will be formed.
• In the present geometry, we could not found find any intersections, mismatches, and connection to other components.
• This can lead to the misinterpretation of results and the effect of these overlappings will be seen in other or neighboring components results.
• Totally the overall results may be seen as garbage.
• So the given geometry is a clean geometry and ready to use for the Icepak simulation after identifying the components by Icepak.

Conclusion:

The conclusion of the challenge is, we dumped the given CAD model into the SpaceClaim, and using the SpaceClaim tools we identify the objects as an Icepak object. After this step, we manually inspect the object using specification types (Level 0,1,2,3) and make Icepak to identify the remaining object.

After that, we save the model in the Icepak file type, and unpacked in the Icepak for the verification of the components, that all the components are identified and dumped in the Icepak.

Additional Information:

Meshing:

• The above figure is a heat sink mesh.