FluidProperties System

Source

To access the fluid properties defined in the Fluid Properties module in a MOOSE object, the source code of the object must include the following lines of code.

In the header file of the material, a const reference to the base SinglePhaseFluidProperties object is required:

  const SinglePhaseFluidProperties & _fp;

class SinglePhaseFluidProperties;

In the source file, the SinglePhaseFluidProperties class must be included

#include "SinglePhaseFluidProperties.h"

The Fluid Properties UserObject is passed to this material in the input file by adding a UserObject name parameters in the input parameters:

  params.addRequiredParam<UserObjectName>("fp", "The name of the user object for fluid properties");

The reference to the UserObject is then initialized in the constructor using

    _fp(getUserObject<SinglePhaseFluidProperties>("fp"))

The properties defined in the Fluid Properties UserObject can now be accessed through the reference. In this material, the computeQpProperties method calculates a number of properties at the quadrature points using the values of _v[_qp] and _e[_qp].

FluidPropertiesMaterialVE::computeQpProperties()
{
  _p[_qp] = _fp.p_from_v_e(_v[_qp], _e[_qp]);
  _T[_qp] = _fp.T_from_v_e(_v[_qp], _e[_qp]);
  _c[_qp] = _fp.c_from_v_e(_v[_qp], _e[_qp]);
  _cp[_qp] = _fp.cp_from_v_e(_v[_qp], _e[_qp]);
  _cv[_qp] = _fp.cv_from_v_e(_v[_qp], _e[_qp]);
  _mu[_qp] = _fp.mu_from_v_e(_v[_qp], _e[_qp]);
  _k[_qp] = _fp.k_from_v_e(_v[_qp], _e[_qp]);
  _s[_qp] = _fp.s_from_v_e(_v[_qp], _e[_qp]);
  _g[_qp] = _fp.g_from_v_e(_v[_qp], _e[_qp]);
}

In a similar fashion, fluid properties can be accessed using the Automatic Differentiation interface using the DualReal version which provides both the value and derivatives

DualReal rho = _fp.p_from_T_v(T, v);

where and are DualReal's. The result (density rho in this example) then contains both the value of density and its derivatives with respect to the primary variables T and v.

Input file syntax

The Fluid Properties UserObjects are implemented in an input file in the FluidProperties block. For example, to use the ideal gas formulation for specific volume and energy, the input file syntax would be:

[FluidProperties]
  [./ideal_gas]
    type = IdealGasFluidProperties
    gamma = 1.4
    molar_mass = 1.000536678700361
  [../]
[]

In this example, the user has specified a value for gamma (the ratio of isobaric to isochoric specific heat capacities), and R, the universal gas constant.

The fluid properties can then be accessed by other MOOSE objects through the name given in the input file.

[Materials]
  [./fp_mat]
    type = FluidPropertiesMaterialVE
    e = e
    v = v
    fp = ideal_gas
  [../]
[]

Due to the consistent interface for fluid properties, a different fluid can be substituted in the input file be changing the type of the UserObject. For example, to use a stiffened gas instead of an ideal gas, the only modification required in the input file is

[FluidProperties]
  [./sg]
    type = StiffenedGasFluidProperties
    gamma = 2.35
    q = -1167e3
    q_prime = 0
    p_inf = 1.e9
    cv = 1816

    mu = 0.9
    k = 0.6
  [../]
[]

Fluid Properties Interrogator

The FluidPropertiesInterrogator is a user object which can be used to query eligible fluid properties objects.

Fluid properties materials

The FluidPropertiesMaterialVE and FluidPropertiesMaterialPT are materials which define many fluid properties as material properties, mainly for visualizing them over the solve domain.