Learning Forum

[Raheem Shaik (IIT KGP)]

Hello all,

I am using udf to print the variables in a text file. It is printing the results but for each timestep, it is printing two times. First, it is showing the correct values and next time it is printing  -1#IND00 values. I don't know the reasong for printing like this. I am attaching the image of the printing file. Please reply if anyone knows about the issue.

Thank you...

 

[Rob]

How many nodes are you running on? How many phases are there? 

[Raheem Shaik (IIT KGP)]

 

Parallel (local machine)

solver processes: 1

Fluent is running on 6 CPU cores.

Domain is having 12000 nodes and only single phase is there.

 

 

 

 

 

[Rob]

OK, so it's not likely to be a parallel issue. If you set up a report for those values in Fluent how does the plot look? 

[Raheem Shaik (IIT KGP)]

Plots are normal. It is taking correct values only for every time step. Only problem is with printing.

I have another doubt about the verbosity. I have set that to 1 to see equations tolerance. After some time of simulation, temperature equation tolerance going like 1.643e+3 and then it is stopping the simulation with the message "" Exit as omega becomes NaN for a norm of s equals to   0.0000e+00 "". I am getting floating point exception. I have no idea how to get rid of the issue.

 

[Rob]

That's diverging. Have a look at the flow field just before it fails to see what's going on. 

[Raheem Shaik (IIT KGP)]

Actually i have printed the values of the flow variables(Pressure and temperature of the domain) at every iteration using define_adjust macro. I have not observed any abnormal values before error encountered.

[Raheem Shaik (IIT KGP)]

Thank you for giving response.

First error in printing now got resolved. Actually problem is with udf Define_execute_at_end where i gave file open pointer inside the macro. Now I have kept it before the macro. It is printing correctly now without -1#IND00 values..

😊

[Rob]

If it's "just failing" try and restart from an autosave. Otherwise look at what's going on in the flow (images not just numbers) to see if something is going on.