[dfresne03]

Hello all, this is my first post here on these forums. I have found this forum to be very helpful with ANSYS issues, but I could not find something similar to my issue.

I am simulating the temperature distribution inside a circuit board. There are two substrates, one is silicon and the other is glass. Each substrate contains four silicon chips. Two are memory, two are logic and as such they give off different amounts of heat.

I would like to study the effect of spacing between these chips on the substrate and the resultant maximum temperature on the face of the substrate.

The input parameters are therefore the distance between each chip.

In the Results section I have defined the appropriate function and output parameters.

However, once I have defined the boundary locations for each chip face and run the study, I get an error:

ERROR:
In Analysis 'Flow Analysis 1' - Domain 'Logic1': One or more of the locations specified for boundary 'Logic1 Default' is already being used for another boundary or interface.

ERROR:
The parameter "Location" in "/FLOW:Flow Analysis 1/DOMAIN:Logic1/BOUNDARY:Boundary 1" holds the following disallowed value: "F69.85". (Allowed values are: "F64.85, F65.85, F66.85, F67.85, ...".)

The initial design point will run fine, but then when it loads in the next design point, this error is thrown.

I can re define the boundary locations and run that particular design point successfully. But then the same error will be thrown once it attempts the next design point.

However, doing this for 10+ different design points would be foolish.

See attached screenshots for some elaboration on the geometry and errors.


Thanks in advance!

[ghorrocks]

You have to dive into CFX-Pre and fix those error surfaces. You will need to replace the ones reported missing with the correct surfaces.

[dfresne03]

Originally Posted by ghorrocks

You have to dive into CFX-Pre and fix those error surfaces. You will need to replace the ones reported missing with the correct surfaces.

Yes, I know. The issue is that after I replace the missing surfaces, the subsequent design point fails again and surfaces are missing again.

The error code doesn't say WHY this is occurring.

[ghorrocks]

The error is occuring because when you generate new geometry in the parameteric sweep it is not keeping the face names the same, so CFX is getting confused as it cannot find the faces it expects.

To get around this I would recommend using some named selections to give important faces defined names and use these names in CFX to define your interfaces and boundaries. Then you have a better chance of CFX staying with the correct faces and avoiding the error.

[dfresne03]

Originally Posted by ghorrocks

The error is occuring because when you generate new geometry in the parameteric sweep it is not keeping the face names the same, so CFX is getting confused as it cannot find the faces it expects.

To get around this I would recommend using some named selections to give important faces defined names and use these names in CFX to define your interfaces and boundaries. Then you have a better chance of CFX staying with the correct faces and avoiding the error.

Okay, I will give that a try.

[dfresne03]

Update, created named locations for the faces and bodies of chips on the substrate. Still getting the boundary location error.

ERROR:
The parameter "Location" in "/FLOW:Flow Analysis 1/DOMAIN:Logic2/BOUNDARY:Boundary 2" holds the following disallowed value: "Logic2PowerSilicon". (Allowed values are: "F74.84, F75.84, F76.84, F77.84, ...".)

ERROR:
The parameter "Location" in "/FLOW:Flow Analysis 1/DOMAIN:Memory1/BOUNDARY:Boundary 3" holds the following disallowed value: "Memory1PowerSilicon". (Allowed values are: "F69.85, F70.85, F71.85, F72.85, ...".)

ERROR:
The parameter "Location" in "/FLOW:Flow Analysis 1/DOMAIN:Memory2/BOUNDARY:Boundary 4" holds the following disallowed value: "Memory2PowerSilicon". (Allowed values are: "F64.92, F65.92, F66.92, F67.92, ...".)

[dfresne03]

Does it matter if the named selections are created in geometry or mesh?

[dfresne03]

Okay... I'm really lost here. ANSYS is shifting around my named selections.

Originally, the left side were "Logic1Chip" and "Logic2Chip", the right side were "Memory1Chip" and "Memory2Chip".

After trying to load another design point, the named selections for the bodies have gotten switched around.

However, the named selections for the faces are in their correct locations...

See the attachments for the moved locations and correct orientation.

[dfresne03]

bump..............

[ghorrocks]

There is nothing much we can suggest. You are just going to have to find a way of modelling it where the faces do not move around. So try different ways of generating it. The geometry is very simple so it should be possible.

[vivjk94]

I got the same error when adding default domain fluid. My inlet and outlet locations get reset and I no longer can find the inlet and outlet which I had defined as named selections.