Problem in compiling specific heat UDF

- August 23, 2021 at 2:36 am
  
  waqas12345
  Subscriber
  
  Hello everyone. Please find below the specific heat UDF which I intend to compile in 2021R1 academic version of fluent. I receive the following error message shown in the image.
  ji.c
  ....srcji.c(81) : error C2143: syntax error : missing ')' before 'constant'
  ....srcji.c(81) : error C2143: syntax error : missing '{' before 'constant'
  ....srcji.c(81) : error C2059: syntax error : 'constant'
  ....srcji.c(81) : error C2059: syntax error : ')'
  NMAKE : fatal error U1077: '"C:Program Files (x86)Microsoft Visual Studio 12.0VCBINx86_amd64cl.EXE"' : return code '0x2'
  Stop.
  Done.
  
  Line 81 is the very first line of my UDF. DEFINE_SPECIFIC_HEAT(my_udf_sp,T,Tref,h,yi), also mentioned in bold letter.
  
  DEFINE_SPECIFIC_HEAT(my_udf_sp,T,Tref,h,yi)
  {
  real Cp;
  real gamma;
  if (T >= 298.0 && T <= 855.0)
  {
  gamma = 0;
  }
  else if (T > 855.0 && T < 925.0)
  {
  gamma = (T - 855.0) / (925.0 - 855.0);
  }
  else if (T >= 925.0 && T<=2790)
  {
  gamma = 1.0;
  }
  else
  {
  gamma = 0;
  }
  if (T >= 298.0 && T <= 855.0)
  {
  Cp = 900.0 + 0.3*(T - 298.0);
  }
  else if (T > 855.0 && T < 925.0)
  {
  Cp = (1 - gamma)*(900.0 + 0.3*(T - 298.0)) + gamma*1170.0;
  }
  else if (T >=925.0)
  {
  Cp = 1170.0;
  }
  *h = Cp*(T - Tref);
  return Cp;
  }
  
  Can someone please help me in identifying the problem.?
  Thank you for your time and support.
- August 23, 2021 at 10:36 am
  
  Rob
  Forum Moderator
  
  Check lines 75-80 too, it may be you've missed a bracket terminating the previous block of text. If you save the file as .c in Notepad++ (for example) the editor is good for working out which bracket pairs are closed.
- August 23, 2021 at 11:11 am
  
  DrAmine
  Ansys Employee
  
  Use good Editors with Syntax Highlighting to avoid missing brackets. I won't use any UDF here you can just rely on NASA Polynomials for Cp or piecewise linear profile.
- August 23, 2021 at 10:08 pm
  
  waqas12345
  Subscriber
  
  Thanx Rob and Dr Amine.
  I tried to change the location specific heat UDF. I even tried to compile it alone but the console always pointed towards the line containing the DEFINE_SPECIFIC_HEAT
  I will also try with NASA polynomial but I am not understanding why this error occurs. My fluent version is 2021R1 academic and I am using VS 2013. Up till now, all my UDFs are working fine. Only this is creating problem in compiling.
- August 23, 2021 at 10:08 pm
  
  waqas12345
  Subscriber
- August 24, 2021 at 9:59 am
  
  Rob
  Forum Moderator
  
  Did you copy the line from the manual using CTRL+C or did you type it in? Check for white space characters if it's the former.
- August 24, 2021 at 11:21 am
  
  DrAmine
  Ansys Employee
  
  In Editor display Tabs and White Spaces and remove unnecessary.
- August 28, 2021 at 12:24 pm
  
  waqas12345
  Subscriber
  
  Problem solved as advised by both of you. Thank you