[mazhar16823]

Hi,

I am running the simulation where I wanted to observe the CFL as a report in STARCCM+. I created the report: Report>New Report>Expression and in properties defined it as $CFL and created the monitor and plot. But I see that after 5-6 iterations an error appears saying that ''CFL references itself'' and simulation is stopped. Can you please tell why is that happening?

[LuckyTran]

You probably set the trigger to time-step and that's why it error'd after a few iterations and not immediately.


But how did you define the CFL? That's kind of important.

[mazhar16823]

Originally Posted by LuckyTran

How did you define the CFL? You probably set the trigger to time-step and that's why it error'd after a few iterations and not immediately

Yes. - I have created the expression report for CFL as Report>new report>expression and in its properties I defined it as $CFL as mentioned in the user guide. With all that, I wanted to autosave the file because due to poor internet my VPN gets disconnected from the university and the simulation is destroyed. I did following to autosave the simulation.

First, I tried using autosave batch runs and enabled the autosave with trigger set to times-step but it didn't work (error: CFL references itself) however for saving the file it says that disk space is insufficient but I have 41 GB available in my flash drive.

Then, I changed the trigger to iteration, enabled the autosave option and chose ''autosave after next time-step'' again both problems occurred 1)CFL references itself 2) insufficient disk space

Finally, I disabled the autosave option and set the trigger to iterations but still the same - no progress.

What should I do??

[LuckyTran]

Let me say it again, how did you define CFL. Saying I did it according to the user guide and therefore it should work isn't going to help debug what you might have done wrong.


Setting the trigger to iterations isn't going to change a circular reference error because it is a circular referencing error not a trigger error.


For the other problem, you probably lack privileges to write to the directory.

[mazhar16823]

Originally Posted by LuckyTran

Let me say it again, how did you define CFL. Saying I did it according to the user guide and therefore it should work isn't going to help debug what you might have done wrong.


Setting the trigger to iterations isn't going to change a circular reference error because it is a circular referencing error not a trigger error.


For the other problem, you probably lack privileges to write to the directory.

As I mentioned earlier that, for the ''Expression'' report, I needed to provide defintion for CFL in the properties window and to do that it was recommended to write ''$CFL'' in definition. I have re-checked it. However, there is another option for option for ''Periodicity'' in properties window do I need to choose ''Periodic'' as I have a blade geometry rotating?.

[LuckyTran]

Go to tools=> field functions and confirm there is a field function named CFL and whether it is a built-in function or user defined function. If it is a user defined function, tell me what is its definition.


Otherwise, have a good day.

[mazhar16823]

Originally Posted by LuckyTran

Go to tools=> field functions and confirm there is a field function named CFL and whether it is a built-in function or user defined function. If it is a user defined function, tell me what is its definition.


Otherwise, have a good day.

Thanks for your time. I looked into Tools>field functions where I see the CFL as ''CFL:Report'' however if I look for its definition in the list of all the field functions there is ''Convective Courant Number'' and choosing that definition gives me an error ''Unable to compile expression ''${Convective Courant Number}$''.

[LuckyTran]

I just want to remind you again, this is why saying "I did it" doesn't help. If you had been forthcoming with what you did, could've been out of this mess days ago.

When you type $CFL into the expression of a report, youare saying find a scalar field function named CFL. You have no field function named $CFL.

The CFL:Report is the report that you just created and defined as $CFL.

There shouldn't be a $ after Convective Courant Number.

There's lots of available fields you can use. You can just define it to be one of those. The next thing is, you are working with fields, whereas a report likes to return 1 value. You need to create a max/min/avg report or make an appropriate expression that returns an expression and not a field.

So instead of doing everything according to this mysterious user guide. Try that instead. Make a maximum report of the convective courant number.

[mazhar16823]

Originally Posted by LuckyTran

I just want to remind you again, this is why saying "I did it" doesn't help. If you had been forthcoming with what you did, could've been out of this mess days ago.

When you type $CFL into the expression of a report, youare saying find a scalar field function named CFL. You have no field function named $CFL.

The CFL:Report is the report that you just created and defined as $CFL.

There shouldn't be a $ after Convective Courant Number.

There's lots of available fields you can use. You can just define it to be one of those. The next thing is, you are working with fields, whereas a report likes to return 1 value. You need to create a max/min/avg report or make an appropriate expression that returns an expression and not a field.

So instead of doing everything according to this mysterious user guide. Try that instead. Make a maximum report of the convective courant number.

Got it. Thank you so much.