[cik mimi]

Good morning,

May I ask, I have a udf code with DEFINE macros as given below:

Define_init
Define_source
Define_adjust
Define_on_demand

I have an experience the divergence of the AMG solver(related to pressure).
I have set to low ratio of mesh to avoid the problem.

Is it the problem is probably come from the specific MACRO Define_source?

Thank you.

[Bruno Machado]

Originally Posted by cik mimi

Good morning,

May I ask, I have a udf code with DEFINE macros as given below:

Define_init
Define_source
Define_adjust
Define_on_demand

I have an experience the divergence of the AMG solver(related to pressure).
I have set to low ratio of mesh to avoid the problem.

Is it the problem is probably come from the specific MACRO Define_source?

Thank you.

it can be many reasons. The DEFINE_ON_DEMAND do not play any role during iterations, so your problem is not there. You can do couple of checks to narrow your problem.

1st) Check if the values of the DEFINE_INIT are correct and fluent is recognizing it (plot the contours and see if the values are what you expect)

2nd) Plot messages with your variable in your source and see if you are getting what it is supposed to be. Change the variables bellow for yours and see what it returns to you. Double check with your hand calculation.

Message ("Variable1 = %f, Varibale2 %f/n", Variable1, Variable2)

3rd) If the 2 previous steps are OK, do the 2nd step on the DEFINE_ADJUST macro

4th) Check the under-relaxation factors;

[cik mimi]

Okey Bruno Machado,

Appreciate for the steps given.

I will give my feedbacks later =)

[cik mimi]

Good day Bruno Machado,

Can I just testing my UDF code with the message of output file without inserting the load model together ?

Thank you.

[Bruno Machado]

Originally Posted by cik mimi

Good day Bruno Machado,

Can I just testing my UDF code with the message of output file without inserting the load model together ?

Thank you.

I didnt get what you said. But, I would test the UDF using my model, otherwise, how can I know if it is working?

[cik mimi]

Good day Bruno Machado,

I am a new user to Ansyst Fluent.
Currently i have a udf code that need to be solve. The code is already written but it has
AMG divergence error.
I did not have my own Ansyst software and if I want to use it, i need to use someone's computer. So I am not always in front of the Ansyst. Therefore, I do not exactly know how it works to retrieve the output file from the UDF code.

Thank you.

My current step is to locate the message () from DEFINE_source to detect the where the divergence error is came from.

[Bruno Machado]

Originally Posted by cik mimi

Good day Bruno Machado,

I am a new user to Ansyst Fluent.
Currently i have a udf code that need to be solve. The code is already written but it has
AMG divergence error.
I did not have my own Ansyst software and if I want to use it, i need to use someone's computer. So I am not always in front of the Ansyst. Therefore, I do not exactly know how it works to retrieve the output file from the UDF code.

Thank you.

My current step is to locate the message () from DEFINE_source to detect the where the divergence error is came from.

you will not have any output file adding the Message() in your code. This message will be printed in the GUI.

To test your UDF, there is no other way rather than trying it on Fluent. If you are a student, you might be able to download a free student version on the website. have a look at it.

[cik mimi]

Okey. I am a student.

My laptop is 32 bit.

So I can only using Ansyst on computer in office which is already download.

[cik mimi]

Good day,

May I ask, in order to retrieve the UDF data through message (),

is it involved in hooking UDF?

Thank you

[Bruno Machado]

Originally Posted by cik mimi

Good day,

May I ask, in order to retrieve the UDF data through message (),

is it involved in hooking UDF?

Thank you

You will see the message when you run your case with the udf hooked.

[cik mimi]

Thank you. I try to make my UDF code works