Respected Sirs,
I am trying to specify the properties of water in supercritical region by interpreting a property UDF in fluent but unable to initialize due to following error
received a fatal signal (Segmentation fault).
the UDF is
/*********************************************************************/
/* UDF for specifying a temperature-dependent density property */
/*********************************************************************/
#include "udf.h"
DEFINE_PROPERTY(cell_density, cell, thread)
{
real den;
real T = C_T(cell, thread);
if (T < 656.)
den = -37540000000 + 366700000000*cos(T*0.002949) - 139500000000*cos(2*T*0.002949) - 494500000000*sin(2*T*0.002949) - 378500000000*cos(3*T*0.002949) + 201700000000*sin(3*T*0.002949) + 156100000000*cos(4*T*0.002949) + 189600000000*sin(4*T*0.002949) + 62480000000*cos(5*T*0.002949) - 75910000000*sin(5*T*0.002949) - 23330000000*cos(6*T*0.002949) - 12700000000*sin(6*T*0.002949) - 1336000000*cos(7*T*0.002949) + 4171000000*sin(7*T*0.002949) + 332400000*cos(8*T*0.002949) + 40860000*sin(8*T*0.002949);
else
den = 66200000000 + 506600000000*cos(T*0.001925) + 242500000000*cos(2*T*0.001925) - 661000000000*sin(2*T*0.001925) - 475200000000*cos(3*T*0.001925) - 344100000000*sin(3*T*0.001925) - 259400000000*cos(4*T*0.001925) + 213400000000*sin(4*T*0.001925) + 57380000000*cos(5*T*0.001925) + 121600000000*sin(5*T*0.001925) + 35620000000*cos(6*T*0.001925) - 7114000000*sin(6*T*0.001925) + 266200000*cos(7*T*0.001925) - 5986000000*sin(7*T*0.001925) - 439800000*cos(8*T*0.001925) - 128700000*sin(8*T*0.001925);
return den;
}
please help me in finding error.
Instead of interpreting the UDF I would suggest to compile it:
user-defined>functions>compiled
and the clicking add you'll be able to select your UDF.
Once selected you can press build and load buttons to compile your UDF.
In case of errors you can have a look on the automatically generated log-file in which you can find useful information on the location, in terms of line number, of the problematic instructions in the UDF.
@simone for compiling , he needs visual studio or any other C compiler right?
It depends on the operating system on which Fluent is executed; if Windows is the reference OS the answer is yes, visual studio is needed. Conversely, if Linux is the reference OS none other software is required since its own compiler is used.
I forgot to mention before that it is also important to be sure that the UDF file is located in the same folder of the fluent .cas file.
Make a simple test run by replacing the entire if/else structure by:
Message(" T = %12.8f\n ",T);
Then see if any value of T is not initialized or has infinitely-large value.
In addition to Simone answer, there should be no space or special character while naming the working directory folder.
In window OS, Fluent or workbench need to be open using compiler. Also the .c file should be copied in the same working directory i.e. FFF-
Yes, You should try to compile it first.. The following previous questions may help you further..
1) https://www.researchgate.net/post/How_to_write_UDF_for_ANSYS_Fluent/1
2) https://www.researchgate.net/post/How_can_I_load_the_UDF_code_in_ANSYS_Fluent?_tpcectx=profile_answers
Good Luck
Dear all, thanks a lot for your help. I will let you know of further issues, if any.
I got the following error when i tried to compile my UDF
Copied C:\Users\Kashifz\Desktop\Visual UDF/C:\Users\Kashifz\Desktop\Visual UDF\Density - Copy.c to libudf\src
user_nt.udf file is outdated. So, recreating the file for 2ddp ...
(chdir "libudf\win64\2ddp")C:\Users\Kashifz\Desktop\Visual UDF\libudf\win64\2ddp\libudf.dll
(system "copy "F:\Softwares\Ansys 16.1 { 64 Bit }\Installation\ANSYS Inc\v161\fluent"\fluent16.1.0\src\udf\makefile_nt.udf "libudf\win64\2ddp\makefile" ")
1 file(s) copied.
(chdir "libudf")(chdir "win64\2ddp")
Done.
and when then if i try to load the UDF i got the error message that the lib you are trying to reach is not generated
Please help me resolve this problem
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