[oliveira1820]

I tried to define liquid water with the correspondent NASA polymonials

LIBRARY:
&replace MATERIAL: NASA AGUA L
Material Description = Water Vapour
Material Group = Gas Phase Combustion,Interphase Mass Transfer,Water Data
Object Origin = User
Option = Pure Substance
Thermodynamic State = Liquid
PROPERTIES:
Option = General Material
ABSORPTION COEFFICIENT:
Absorption Coefficient = 1.0 [m^-1]
Option = Value
END
DYNAMIC VISCOSITY:
Dynamic Viscosity = 0.0005 [kg m^-1 s^-1]
Option = Value
END
EQUATION OF STATE:
Density = 998 [kg m^-3]
Molar Mass = 18.02 [kg kmol^-1]
Option = Value
END
REFERENCE STATE:
Option = NASA Format
Reference Pressure = 1 [atm]
Reference Temperature = 25 [C]
END
REFRACTIVE INDEX:
Option = Value
Refractive Index = 1.0 [m m^-1]
END
SCATTERING COEFFICIENT:
Option = Value
Scattering Coefficient = 0.0 [m^-1]
END
SPECIFIC HEAT CAPACITY:
Option = NASA Format
LOWER INTERVAL COEFFICIENTS:
NASA a1 = 7.25575e01
NASA a2 = -0.662445 [K^-1]
NASA a3 = 0.00256198746 [K^-2]
NASA a4 = -4.36591923e-06 [K^-3]
NASA a5 = 2.78178981e-09 [K^-4]
NASA a6 = -41886.5499 [K]
NASA a7 = -288.280137
END
TEMPERATURE LIMITS:
Lower Temperature = 273.150 [K]
Midpoint Temperature = 1000 [K]
Upper Temperature = 600.000 [K]
END
UPPER INTERVAL COEFFICIENTS:
NASA a1 = 0
NASA a2 = 0 [K^-1]
NASA a3 = 0 [K^-2]
NASA a4 = 0 [K^-3]
NASA a5 = 0 [K^-4]
NASA a6 = 0 [K]
NASA a7 = 0
END
END
THERMAL CONDUCTIVITY:
Option = Value
Thermal Conductivity = 0.64 [W m^-1 K^-1]
END
END
END
END




and the software solver crashes with the following message:

Error in subroutine CALVAR_PROP :
Error calculating Thermal Expansivity
GETVAR originally called by subroutine CAL_GVar

Does anyone knows why?

[ghorrocks]

You could have entered the coefficients wrongly, you could be using the model in a temperature or pressure it is not accurate for, your model could be diverging. It is going to be one of those reasons. You need to do debugging to find which.

[Opaque]

Careful with your material definition.

You have provided a constant density material, and the software is requesting the thermal expansivity, i.e. derivative of density respect to temperature and constant pressure times something else.

Are you using a buoyancy model of some sort? Bousinessq model relies on the thermal expansivity, therefore my guess.