Line data    Source code

       1             : //* This file is part of the MOOSE framework
       2             : //* https://mooseframework.inl.gov
       3             : //*
       4             : //* All rights reserved, see COPYRIGHT for full restrictions
       5             : //* https://github.com/idaholab/moose/blob/master/COPYRIGHT
       6             : //*
       7             : //* Licensed under LGPL 2.1, please see LICENSE for details
       8             : //* https://www.gnu.org/licenses/lgpl-2.1.html
       9             : 
      10             : #include "VanDerWaalsFreeEnergy.h"
      11             : 
      12             : registerMooseObject("PhaseFieldApp", VanDerWaalsFreeEnergy);
      13             : 
      14             : InputParameters
      15          47 : VanDerWaalsFreeEnergy::validParams()
      16             : {
      17          47 :   InputParameters params = GasFreeEnergyBase::validParams();
      18          47 :   params.addClassDescription("Free energy of a Van der Waals gas.");
      19          94 :   params.addRequiredParam<Real>("a",
      20             :                                 "Van der Waals coefficient a (default mass_unit_conversion "
      21             :                                 "requires this to be in [eV*Ang^3])");
      22          94 :   params.addRequiredParam<Real>("b",
      23             :                                 "Van der Waals molecular exclusion volume b (default "
      24             :                                 "mass_unit_conversion requires this to be in [Ang^3])");
      25          94 :   params.addParam<Real>("log_tol",
      26          94 :                         0.1,
      27             :                         "The logarithm in the free energy is evaluated using a Taylor expansion "
      28             :                         "below this value. This allows formulating free energies for systems where "
      29             :                         "the molecular volume is smaller than the exclusion volume b.");
      30          47 :   return params;
      31           0 : }
      32             : 
      33          36 : VanDerWaalsFreeEnergy::VanDerWaalsFreeEnergy(const InputParameters & parameters)
      34             :   : GasFreeEnergyBase(parameters),
      35          36 :     _a(getParam<Real>("a")),
      36          72 :     _b(getParam<Real>("b")),
      37         108 :     _log_tol(getParam<Real>("log_tol"))
      38             : {
      39             :   // Definition of the free energy for the expression builder
      40          36 :   EBFunction free_energy;
      41          36 :   free_energy(_c, _T) =
      42         108 :       -_n * _kB * _T * (plog(_nq * (1.0 / _n - _b), _log_tol) + 1.0) - _n * _n * _a;
      43             : 
      44             :   // Parse function for automatic differentiation
      45          36 :   functionParse(free_energy);
      46          36 : }