Assign limit in udf for Temperaure and Pressure

 Register Blogs Members List Search Today's Posts Mark Forums Read

 October 15, 2012, 10:45 Assign limit in udf for Temperaure and Pressure #1 New Member   Yogini Patel Join Date: Jan 2010 Location: Finland Posts: 15 Rep Power: 7 Hello, I am writing my udf in fluent for material properties. Where I have to assign certain limit for both temperature and pressure in the beginning of the udf. Also this bounded value, I want to use it in other properties in the same udf. Can any one give me some ideas how I can define limit in udf ? Thank you BR, -Yogini

October 16, 2012, 21:25
#2
Senior Member

Syavash
Join Date: Apr 2010
Location: Tehran, Karaj
Posts: 241
Rep Power: 8
Quote:
 Originally Posted by Yogini Hello, I am writing my udf in fluent for material properties. Where I have to assign certain limit for both temperature and pressure in the beginning of the udf. Also this bounded value, I want to use it in other properties in the same udf. Can any one give me some ideas how I can define limit in udf ? Thank you BR, -Yogini

You can establish a loop over either faces or cells and check the parameters you wish. If their values would have exceeded maximum range, you can be informed by an if-clause, for example:

if (C_P(c,t) > 1e+10)
Error("pressure has exceeded maximum range");

Above command lines will stop UDF procedure.

Goodluck

 October 17, 2012, 10:11 #3 New Member   Yogini Patel Join Date: Jan 2010 Location: Finland Posts: 15 Rep Power: 7 Hello, Thank you for your reply. In my case I am using wet-steam udf for calculating thermodynamical properties (like, P, T, Cp, Cv, rho, etc). All are the functions of T and Rho in polynomial form. In my case, the calculated values in fluent increased too much. That's why I want to set a certain limit for Temp. and rho. Like one example, P = f(T,rho), if T > 360 K then T = 360 K else T = T Same for rho also. I want to put this 'if-else' clause in my udf, can you guide me how to write it? -Yogini

October 17, 2012, 11:44
#4
Senior Member

Syavash
Join Date: Apr 2010
Location: Tehran, Karaj
Posts: 241
Rep Power: 8
Quote:
 Originally Posted by Yogini Hello, Thank you for your reply. In my case I am using wet-steam udf for calculating thermodynamical properties (like, P, T, Cp, Cv, rho, etc). All are the functions of T and Rho in polynomial form. In my case, the calculated values in fluent increased too much. That's why I want to set a certain limit for Temp. and rho. Like one example, P = f(T,rho), if T > 360 K then T = 360 K else T = T Same for rho also. I want to put this 'if-else' clause in my udf, can you guide me how to write it? -Yogini

Tell us more about your UDF. What kind of Macro is used?

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post Vitalij FLUENT 1 April 10, 2007 03:39 Amir FLUENT 2 September 1, 2005 18:59 D Harvey FLUENT 2 June 3, 2004 21:46 DS & HB Main CFD Forum 0 January 8, 2000 16:00 Jonas Larsson Main CFD Forum 1 April 29, 1999 10:44

All times are GMT -4. The time now is 07:00.