[Reivax]

Hi,
I'm encountering a problem in my simulation while using the NIST real gas model in Fluent 15.0. I'm trying to simulate a flow in a cooling channel using the following model :

• COOLANT

  liquid hydrogen from the NIST database

  velocity: 40 m/s

  Pressure: 26 MPa

  Temperature: 52.4K

• TEMPERATURE OF THE WALLS

  Inner Wall: 270K (constant)

  Outer Wall: 700K (constant)

  Side Wall: I use an udf to make a linear variation of the temperature from one edge to the other
  

  #include "udf.h"
  
  DEFINE_PROFILE (gradient_temp1,t,i)
  {
  	real x[ND_ND];
  	real y;
  	face_t f;
  
  	begin_f_loop (f,t)
  		{
  			F_CENTROID(x,f,t);
  			y = x[0];
  			F_PROFILE(f,t,i) = -156193.2437*y - 7572.6189;
  		}
  	end_f_loop (f,t)
  }
  
  DEFINE_PROFILE (gradient_temp2,t,i)
  {
  	real x[ND_ND];
  	real u;
  	face_t f;
  
  	begin_f_loop (f,t)
  		{
  			F_CENTROID(x,f,t);
  			u = sqrt(x[0]*x[0]+x[1]*x[1]);
  			F_PROFILE(f,t,i) = 156193.2437*u - 7572.6189;
  		}
  	end_f_loop (f,t)
  }
  
  DEFINE_PROFILE (gradient_temp3,t,i)
  {
  	real x[ND_ND];
  	real v;
  	face_t f;
  
  	begin_f_loop (f,t)
  		{
  			F_CENTROID(x,f,t);
  			v = x[0];
  			F_PROFILE(f,t,i) = 156193.2437341082*v - 7572.6189;
  		}
  	end_f_loop (f,t)
  }

My problem is that when I try to run the calculation it crashes after a few iterations, returning theses messages in the console :


I've run another simulation without any problem using the NIST database but with a constant temperature of 500K for every wall. But this one keep crashing, does anyone has a clue on what might be the problem here ?
If you need more information to solve my problem, please ask.