[Finbar]

Hi,

I'm attempting to examine the effects of the wake from a car using a wind tunnel style geometry. The simulation is being run in 2D, I understand that CFX requires a 3D mesh so I have created CAD geometry with the third dimension being 1/100th the length of the largest dimension in the geometry. [images attatched]


I am using Workbench 17.1 and the Fluid Flow (CFX) analysis system. I can import the CAD geometry and create 'named sections' for the appropriate faces without any issue, however I do not understand how I can mesh the geometry appropriatly for 2D analysis.

From what I have researched, I understand there are a few options. The first option I have found is to define the faces in the z-direction as 'symmetry' and the second was to make use of a feature called 'Extruded 2D Mesh'. Unfortunalty, I am new to CFX (fairly familiar with Fluent) and a lot of the advice I see here is going over my head.

I would appreciate a nudge in the right direction for setting up a CFX project for 2D analysis, specificaly the going from having a CAD model to meshing as a beginner.

Best regards,
Finbar.

[siw]

Since you are using the CFX (Fluid Flow) Analysis System, then you will use Meshing for mesh generation. You can use a Sweep Method with one division in the thickness direction. Use the various sizings, inflation etc. on the source face of the Sweep Method. You can segregate geometry (i.e. in SpaceClaim or DesignModeler) if you want to make bodies of influence to refine the mesh away from edges/points. You can assign Named Selections in Meshing, e.g. call appropriate faces Sides, Inlet etc. to be available in CFX-Pre for the boundary conditions.

[Finbar]

Originally Posted by siw

Since you are using the CFX (Fluid Flow) Analysis System, then you will use Meshing for mesh generation. You can use a Sweep Method with one division in the thickness direction. Use the various sizings, inflation etc. on the source face of the Sweep Method. You can segregate geometry (i.e. in SpaceClaim or DesignModeler) if you want to make bodies of influence to refine the mesh away from edges/points. You can assign Named Selections in Meshing, e.g. call appropriate faces Sides, Inlet etc. to be available in CFX-Pre for the boundary conditions.

https://media.tenor.com/images/1d744...47fb/tenor.gif

On a serious note, thanks for the help. I've got the initial solution to converge but I'm struggling with some of the details you gave. I can't find a way to add inflation layers to the boundaries of the car as using the sweep method makes inflation inactive, giving an 'invalid method' error. From what I can find online a solution to this is to select the 'Source and Target' option for 'Src/Trg Selection', however I can't seem to work out the correct method to apply this. If you could advise me on a way to add inflation I would be extremley grateful.


Also, is it necessary to "segregate geometry"? This is the first time I have heard this expression and the results returned when I search online are limited.