Learning Forum

[SunilM]

 

Hi,

We are attempting to optimize MCHS (Microchannel heat sink) designs using Ansys Fluent. One of our focus areas is to perform optimization of offset fin heat sink designs. We have two parameters to optimize and the combination of the two parameters results in many design possibilities. 

 
We tried to implement a parametric study using the design modeler of Ansys workbench. However, after successfully simulating the first design point, Ansys meshing is not able to maintain consistent named selections for the second design point and is displaying an error regarding the named selections. We tried different options available for simulating various design points, but were not successful and keep getting the same named selection error.
 
Our question is - Do we need Ansys HPC parametric pack license to perform such simulations? 
If we don't need HPC parametric pack licenses, how can we efficiently perform this design optimization study? 
 
Attached paper contains the optimization parameters we are trying to change from one design point to another. "K" and "M" are the design parameters (see page 2 for definitions of "K" and "M" and Fig 1 in page 3 for design based reference). 
 
Thank you for your time. 
 
Kind regards, 
Sunil M. 

 

[Karthik Remella]

Hello Sunil,

You do not need any HPC parametric pack to perform parametric studies in WB. It shoudl work be default.

Regarding your Named Selection issue: It is possible that when your geometry changes, you get a different number of faces / edges than what you originally had. ANSYS Meshing does not know what to do with this change in number. This typically happens when the parametric study is not robust. It is extremely important to ensure that your parametric study is really robust.

When I set a parametric study, I generally test different design points through the stand alone work flow. You could use the values of the failed design point in a standalone manner (not through your design table) and check visually at what happens in the meshing window when the geometry is passed to meshing. You will notice why your DP failed when you inspect your named selection visually through the GUI. 

Please let me know if this worked for you.

Thank you.

Best,

Karthik

[SunilM]

Hello Karthik,

Thank you for the suggestion about the robustness. Previously, in order to generate the fluid volume geometry, we used the Boolean subtract operation in design modeler. We guessed that this was causing the error i.e., unmatched named selections error in Fluent. Now we are using extrude instead of Boolean and this did not cause the mentioned error anymore. Thanks again. 
 
Best regards  
Sunil

[Karthik Remella]

Hi Sunil,

Glad to know you are on the right track.

Thanks.

Best,

Karthik