Hi all, does anyone have a UDF that I could use to switch on the energy equation on a problem after, say 500 iterations? Or even better, one that switches the energy equation on after the continuity residual hits 1e-6? It would save me lots of time when running problems over night.

Any help or advice much appreciated.

Thanks, mat

plz more explain do you want to enable energy equation after 500 iter?

That's right nasser - I want to "enable" or turn on the energy equation (Solve-Controls-Solution) after say 500 equations. It would be even better if I could switch on the energy equation after the continuity residuals reduced to below a certain level.

thanks mat

Do you use segregated model? if you use this model you can. use under relaxtation method bye

I am using a segregated solver, but how will the "under relaxation method" help?

I'm not sure what you mean exactly - a UDF is required in order to automatically enable the energy equation after a certain number of residuals, I'm just not sure how to write it.

Thanks anyway, mat

Hello, you needn't UDF ... you can use a file.jou :

/file/read-case toto.cas.gz

/file/read-data toto.dat.gz

;; you do 500 iterations ...

/solve/iterate 500

;; ... after you switch on energy equation

/define/models/energy? yes

/solve/iterate 1500

/file/write-data toto_end.dat.gz

steph.

Steph,

Thanks for that-sounds good. I'll give it a whirl.

Cheers for the help - it'll save me lots of time.

Mat w