Learning Forum

[Sofen Kumar Jena]

I want to compute interfacial area concentration in Fluent UDF. Ansys document is telling the same can be called using the macro C_IAC(c,t_s);

However the the Fluent compiler does not reconige this command and gives error

It is telling the C_IAC is an undefined symbol. 

from experience I feel, this is temporary solver variable and needs to allocated memory and defined before use

#define C_IAC(c,t) C_STORAGE_R(c,t,SV_xxxxxx)

So something like this needed to added at the top. 

But I am not sure under what name the interfacial area concentration variable is stored in Fluent .

Kindly have a look and inform me what exact name I should replace with SV_xxxxxx to access the C_IAC(c,t).

[Rob]

As it's not referenced in the manual staff are unable to comment.  Given your comment about allocated memory, have you set the flag to retain temporary memory?  https://ansyshelp.ansys.com/account/Secured?returnurl=/Views/Secured/corp/v241/en/flu_udf/flu_udf_DataAccessMacros.html 

 

[Sofen Kumar Jena]

Reference manual on UDf does not have any information regarding how to access the interfacial area. 

I tried to redefine the same with the following statement. 

#define C_IAC_USER(c,t) C_STORAGE_R(c,t,SV_SOLUTION_VAR(IAC))

But the solver unable to reconize SV_SOLUTION_VAR(IAC) :

What variable name one should use to access Interfacial area concentration ?

Cheers 

Sofen 

[Rob]

Please refer to my previous comment. Have you had a more general look in wherever you found the C_STORAGE macro? 

[Sofen Kumar Jena]

Thanks,

Any available documents on list of temporary solver variables and the name to be used to access them. 

The UDF documents have information on some primitive flow variables.

Cheers!

Sofen 

 

[Rob]

You may find you need to read the header files - luckily that's a comment somewhere in the manual. 

[Sofen Kumar Jena]

Yes  it is mentioned that, more things are available in sg_mem.h header file. 

I have extensively searched sg_mem.h header file but did not get any information about the interfacial area concentration there. may be it is there in some other name that, I am not able to get. No proper documents also available for these variable nomenclature.

Cheers 

[Rob]

There may not be any comments and as stated I can't add anything where there's no public information. 

[Sofen Kumar Jena]

Ansys Fluent is a most trusted software having a large number of user community. Solver is calculating the interfacial area concenration and there should be some mechanism to access the same. What the user supposed to do if he needs these information and those are nota available in document or Ansys knowledge database ?

I am forced to use the algebric ia_particle method for computing of interfacial area. But often I needs the interfacial are values computed using the PDE. 

Please suggest the needful . 

 

Cheers

Sofen 

[Rob]

We (staff) cannot discuss nonpublic materials on a public forum. Commercial client interact with the Ansys team in private, so the restrictions are different. 

[Sofen Kumar Jena]

After long trial and search, I found that C_IAC(c,t) is defined in sg_iac.h header file like this

#define C_IAC(c,t)   C_STORAGE_R(c,t,SV_IAC)
#define F_IAC(e,t) C_IAC(e,t)

Loading this header file or redifining the above lines in the header of UDF will help the solver to reconize the 

C_IAC(c,t) command. 

 

 

[Sofen Kumar Jena]