Learning Forum

[cy2019]

Hello, I wanted to create a parameterization study on flow over a cylinder by changing the shape of the cylinder. I know that I can create a group using the defined radius of the cross-sectional area, but that does not change the cylinder negative area of the enclosure that I have created, meaning that the enclosure area to be meshed still has the original sized cylinder as the negative area. 

How can I drive the enclosure geometry by changing the cross-sectional area of the cylinder within Spaceclaim? 

Or is there a method where I can define the entire enclosure as a cube and the cylinder as itself, and mesh both separately such that there is fluid/solid interaction in the final Fluent analysis? 

[peteroznewman]

In SpaceClaim, create the cylinder, then use the Prepare tab and create the Enclosure, then delete the cylinder. You now have a fluid volume. I used the Pull Tool to increase the cylinder length to each end of the Enclosure. It helps to Hide the Face of the Enclosure to get to the cavity face.

With the Pull Tool, click on the cylindrical face, then click on the P button. That will create a Named Selection in the Groups category. I named it CylinderRadius.  That is going to show up in the Parameter Set box in Workbench where you can specify a list of CylinderRadius values to evaluate.

[cy2019]

Thank you  

[cy2019]

Ok another scenario -- what if the cylinder was now air airfoil shape and I wanted to parameterize the angle at which the airfoil is rotated? How could I rotate the airfoil to drive the enclosure's geometry? 

Thank you again! 

[peteroznewman]

Draw the airfoil, create the enclosure, delete the airfoil.

Select the faces of the airfoil cavity in the enclosure and use the Move tool. Drag one of the rotation handles. Type in a value, like 5 degrees, and click the P button to create a Group Named Selection.  Rename that AngleOfAttack, which will show up in the Parameter Set.

If this answers your question, please mark the post with Is Solution to show the discussion is Solved, or ask a followup question.

[Rob]

Your other option is to vary the inlet flow angle: have a look at the velocity options in Fluent.  Peter's approach is better in a confined domain, mine works well for a large domain using far field boundaries as it avoids remeshing. 

[cy2019]

For more complex models, would it be possible to create an Overset Mesh? Such as defining a background mesh as the fluid and creating a secondary (overlapping) mesh as a solid which the fluid must go around? 

[Rob]

It is possible, but it's usually easier to alter the outer boundary: have a look at the airfoil tutorials where a far field boundary has been used. 

[cy2019]

Thank you for all your responses! I was somewhat confused by the term overset mesh when I was looking it up at the time, but the response from peteroznewman was able to help me out. I was using the Move tool but the relationship between the geometry was not cooperating because I did not anchor the center of rotation to the point!