Viscosity-temperature Coupling Parameters

This section describes the parameters for properly modelling viscosity-temperature coupling.

viscTempModels
{
     viscTemp_model
     {
         phase_affected                1
         viscTemp_model                POLYNOMIAL
         poly_coeffs1                  0.0           
         poly_coeffs2                  0.0
         poly_coeffs3                  0.0
         poly_coeffs4                  0.0
         poly_coeffs5                  0.0
    }

    viscTemp_model
    {
         phase_affected                1
         viscTemp_model                SUTHERLAND
         sutherland_refVisc            0.1             
         sutherland_refTemp            273.15          
         sutherland_coefficient        12.01           
    }
  
    viscTemp_model
    {
         phase_affected                1
         viscTemp_model                POWER_LAW
         power_refVisc                 1.716e-5       
         power_refTemp                 273.15          
         power_exponent                0.666           
    }
}

phase_affected: Similar to the phase_motion command, this option tells you which phase is affected by this viscosity-temperature dependence model.
viscTemp_model: Model according to which the viscosity will be calculated as a function of temperature.; Options: POLYNOMIAL / SUTHERLAND / POWER_LAW.

Each viscosity-temperature has its own set of characteristic parameters. For polynomial model those are the five polynomial coefficients, for Sutherland model those are reference viscosity, reference temperature and the Sutherland coefficient. Finally, the power law has reference viscosity, reference temperature and the exponent. For more details about the models see Viscosity-temperature dependence models.

poly_coeffs1, poly_coeffs2, poly_coeffs3, poly_coeffs4, and poly_coeffs5: Polynomial coefficients for the polynomial viscosity-temperature model.; Related options/commands: viscTempCoupling, Viscosity-temperature dependence models
sutherland_refVisc: Sutherland reference viscosity.; Related options/commands: viscTempCoupling, Viscosity-temperature dependence models
sutherland_refTemp: Sutherland reference temperature; Related options/commands: viscTempCoupling, Viscosity-temperature dependence models
sutherland_coefficient: Sutherland coefficient; Related options/commands: viscTempCoupling, Viscosity-temperature dependence models
power_refVisc: Power law reference viscosity; Related options/commands: viscTempCoupling, Viscosity-temperature dependence models
power_refTemp: Power law reference temperature; Related options/commands: viscTempCoupling, Viscosity-temperature dependence models
power_coefficient: Power law exponent; Related options/commands: viscTempCoupling, Viscosity-temperature dependence models

Important: If using the viscTempCoupling capability, all the FLUID phases must have their viscosities defined by one of the three viscTempCoupling models. It is not possible to have one FLUID phase with constant viscosity and others with variable viscosity.