Hello CFX People,

I am continuing my attempt to model a fuel cell with CFX 5.6. Here is my current multicomponent problem:

If I want to remove a certain amount of only one species, I have to use a mass sink. Unfortunately this means I take out some of every species. To counteract this, I wrote some User FORTRAN to figure out how much of the other species come out with my mass sink and I want to then use a mass source (where I can specify a certain mass fraction) to replace the species that were supposed to remain.

So I need to define a mass sink and a mass source on the same Sub-domain. CFX 5.6 will not allow me to do this:

ERROR There is an inconsistency in the problem definition. The location of a number of subdomains overlap. This is not allowed in the current version of the software.

Subdomain "Source" contains the following overlapping regions: "SOURCE"

Subdomain "Sink" contains the following overlapping regions: "SOURCE"

Has anyone out there found a way around this?

Can any one suggest a solution?

Thank you, Jonathan

Hi Jonathan

If you set the environment variable

GTM_BETA_ALLOW_SUBDOMAIN_OVERLAP

to the value 1, this should allow you to set-up multiple subdomains at the same location in CFX-Pre and the CFX-5 Solver.

Regards,

Johnson

Thank you for the suggestion Johnson.

I am probably missing something obvious. Isn't an environment variable used for interacting with your operating system? Do you mean expert parameter? How do you set an environment variable in CFX 5.6?

Sorry for the addition questions, Jonathan

I don't know what the reason is for activating the feature through an environment variable, but it is definitely activated that way. Maybe because it is not a fully supported feature ...

Johnson,

I still haven't been successful in setting up this environmental variable. I created the variable in the cfx5rc file and didn't have any success - same errors. (I hope I did everything correctly.)

How did you implement this environment variable?

It is curious that there is no mention of this in the CFX documentation. Have you used this feature or simply just heard about it?

Jonathan

Hi

It's a little known (and therefore not fully supported) feature, which is why it is not mentioned in the documentation.

You need to set the environment variable on your system, e.g. for unix use

setenv ENV_VAR value

or on Windows, set it by going through the Advanced tab on the System Properties form. When you've set it, restart the CFX-5 launcher and then CFX-Pre and you should be able to set up your sources.

Johnson

Thank you very much. I appreciate your replies.

Jonathan

I've got it working now.

I needed to set GTM_BETA_ALLOW_SUBDOMAIN_OVERLAP=TRUE. (Not 1)

Thanks again for all of your help.

Jonathan