EquilibriumConstantFit Class Reference

Fit the equilibrium constant values read from a databse at specified temperature values with a Maier-Kelly type function for the equilibrium constant. More...

#include <EquilibriumConstantFit.h>

Inheritance diagram for EquilibriumConstantFit:

Public Member Functions
	EquilibriumConstantFit (const std::vector< Real > &temperature, const std::vector< Real > &logk)
virtual Real	sample (Real T) override
virtual void	generate ()
unsigned int	getSampleSize ()
const std::vector< Real > &	getCoefficients ()
void	setVariables (const std::vector< Real > &x, const std::vector< Real > &y)

Protected Member Functions
virtual void	fillMatrix () override
void	doLeastSquares ()

Protected Attributes
std::vector< Real >	_x
std::vector< Real >	_y
std::vector< Real >	_matrix
std::vector< Real >	_coeffs
unsigned int	_num_coeff

Detailed Description

Fit the equilibrium constant values read from a databse at specified temperature values with a Maier-Kelly type function for the equilibrium constant.

log(K)= a_0 ln(T) + a_1 + a_2 T + a_3 / T + a_4 / T^2

where T is the temperature in Kelvin.

Note: at least five data points must be provided to generate a fit

Definition at line 26 of file EquilibriumConstantFit.h.

Constructor & Destructor Documentation

EquilibriumConstantFit()

EquilibriumConstantFit::EquilibriumConstantFit	(	const std::vector< Real > &	temperature,
		const std::vector< Real > &	logk
	)

Definition at line 13 of file EquilibriumConstantFit.C.

  : LeastSquaresFitBase(temperature, logk)
{
  _num_coeff = 5;

  // The number of temperature points and logk points must be equal
  if (temperature.size() != logk.size())
    mooseError(
        "The temperature and logk data sets must be equal in length in EquilibriumConstantFit");

  // At least five data points must be supplied for this functional fit
  if (temperature.size() < 5)
    mooseError("At least five data points are required in EquilibriumConstantFit");
}

Member Function Documentation

fillMatrix()

void EquilibriumConstantFit::fillMatrix ( )

overrideprotectedvirtual

Implements LeastSquaresFitBase.

Definition at line 30 of file EquilibriumConstantFit.C.

{
  unsigned int num_rows = _x.size();
  unsigned int num_cols = _num_coeff;
  _matrix.resize(num_rows * num_cols);

  for (unsigned int row = 0; row < num_rows; ++row)
  {
    _matrix[row] = std::log(_x[row]);
    _matrix[num_rows + row] = 1.0;
    _matrix[(2 * num_rows) + row] = _x[row];
    _matrix[(3 * num_rows) + row] = 1.0 / _x[row];
    _matrix[(4 * num_rows) + row] = 1.0 / _x[row] / _x[row];
  }
}

sample()

Real EquilibriumConstantFit::sample ( Real  T )

overridevirtual

Implements LeastSquaresFitBase.

Definition at line 47 of file EquilibriumConstantFit.C.

Referenced by TEST().

{
  Real logK =
      _coeffs[0] * std::log(T) + _coeffs[1] + _coeffs[2] * T + _coeffs[3] / T + _coeffs[4] / T / T;

  return logK;
}

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The documentation for this class was generated from the following files:

• chemical_reactions/include/utils/EquilibriumConstantFit.h
• chemical_reactions/src/utils/EquilibriumConstantFit.C