Learning Forum

[pankaj16997]

Hi,

I was able to successfully compile my UDF but then I run into a problem  whenever I try entering a parameter into the newly created model(by the UDF).The following is displayed:

Node 999999: Process 9976: Received signal SIGSEGV.

 

==============================================================================

....

 

MPI Application rank 0 exited before MPI_Finalize() with status 2

 The fl process could not be started.

 

The simulation runs fine without the UDF.

Any advice on this matter would be appreciated.

[Rob]

It means that while the code compiles (ie the syntax is correct) but it's not correct for what Fluent needs. Typical issues are that the data doesn't exist or the maths is wrong (eg code returns 0 or infinity). 

[stac]

Hi guys,

i am facing the same Problem. In my case, i have to define a temperature and pressure dependend viscosity and density.

Right after initialisation, i get the error: The fl process could not be started. Therfore i Initialized it before i did set the user defined viscosity and density. But when i want to start the calculation then i get the folliwing error and fluent collapses:
999999: mpt_accept: Error: accept failed: Invalid argument

Please give me some tips why it doesn't work.
Thank you in advance

[Rob]

Turn off the UDF density, and see if viscosity fails. I'd look to see how mu_lam is defined. 

Also, check limitations, historically Fluent didn't like pressure dependent properties that weren't calculated via Ideal Gas or Real Gas inbuilt models: they've been built so as not to mess with the solver numerics. They may work, but be prepared for some convergence problems.