[Captain Convergence]

Hi all

I am having issues with my UDRGM. A the moment I am trying to have a functional UDRGM with ideal-gas formulation before moving on with the real gas formulation. However the available ideal-gas UDRGM examples available in Fluent's User Guide do not work as the ideal-gas formulation available in Fluent. After many hours trying to understand why, I track down the errors and the issues are due to the enthalpy and entropy formulations, which are given like this:

double IDEAL_enthalpy(cell_t cell, Thread *thread, double Ttot, double density, double Ptot, double yi[])
{
double Temp = C_T(cell,thread); /* Cell Static Temperature (K) */
double cp = IDEAL_specific_heat(cell, thread, Temp, density, Pabs, yi); /* (J/Kg/K) */
double h = Temp * cp;
return h; /* (J/Kg) */
}

double REAL_entropy(cell_t cell, Thread *thread, double Ttot, double density, double Ptot, double yi[])
{
double RGAS = Runiv/MW0;
double Temp = C_T(cell,thread); /* Cell Static Temperature (K) */
double Pstat = C_P(cell,thread); /* Cell Static Pressure (Pa) */
double cp = 1004.16; // J/(Kg K)
double s = cp * log(fabs(Temp / TDatum)) + RGAS * log(fabs(PDatum / Pstat));
return s; /* (J/Kg/K) */
}

I have attached a .zip file with the mesh (a 2D simple channel), a journal file (that executes everything for you) and the 2 UDRGMs (one with ideal-gas formulation and the other with real-gas formulation). You can compile and execute the simulations in your computer and check yourselves (it takes less than 1 min to run). If I calculate the enthalpy with the static temperature, the temperature at the inlet tends to 0 Kelvin which indicates that I am undercalculating somehow the enthalpy. I tried to post these questions in ANSYS Student Community but the provided answers were not very helpful (you can read the discussion here: https://studentcommunity.ansys.com/t...unwated-value/). I would appreciate any help regarding this issue or if you could indicate where to fing an UDRGM with ideal formulation that works with Fluent 2019 R3.