This class uses the Chapman Enskog theory for mono-atomic gases to estimate the binary diffusion diffusivity between two gases. More...

#include <BinaryDiffusion.h>

Inheritance diagram for FuelCellShop::Mixture::ChapmanEnskog:

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Collaboration diagram for FuelCellShop::Mixture::ChapmanEnskog:

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Public Member Functions
	ChapmanEnskog ()

	ChapmanEnskog (FuelCellShop::Material::PureGas &species1, FuelCellShop::Material::PureGas &species2)

virtual	~ChapmanEnskog ()

virtual char *	get_name ()

virtual char *	get_description ()

virtual enDiffusionModelID	get_ID ()

virtual double	getSikmaAB (const double &sikma_A, const double &sikma_B)

virtual double	getTstarAB (const double &Tstar_A, const double &Tstar_B)

virtual double	getOmegaAB (const double &Tstar)

virtual void	compute_diffusion (double &D)
	Comupute the diffusion coefficient [in m^2/s] at a given temperature [K] and pressure [atm].

virtual void	compute_diffusion (std::vector< double > &D_vec)
	Compute a vector of diffusion coefficients [in m^2/s] for a non-isothermal, isobaric case.

virtual double	compute_diffusion (const double &T, const double &p)
	Comupute the diffusion coefficient [in m^2/s] at a given temperature [K] and pressure [atm].

virtual void	compute_diffusion (double &D, std::vector< double > &dD)
	Comupute diffusion coefficient [in m^2/s] and the sensitivity of the diffusion coefficient with respect to temperature and pressure.

virtual void	compute_diffusion (const double &T, const double &p, double &D, std::vector< double > &dD)
	Comupute diffusion coefficient [in m^2/s] and the sensitivity of the diffusion coefficient with respect to temperature and pressure at a given temperature [K] and pressure [atm].

virtual void	compute_dD (std::vector< double > &dD)

virtual double	compute_dD_dP (const double &T, const double &p)

virtual double	compute_dD_dT (const double &T, const double &p)

virtual void	compute_dD_dT (std::vector< double > &dD_dT_vec)
	Method to compute derivative of diffusion coefficient with respect to temperature [in m^2/(s-K)] for a non-isothermal, isobaric case, at all quadrature points of the cell.

virtual void	scan ()

virtual void	report ()

virtual void	report2file (char *filename)

Public Member Functions inherited from FuelCellShop::Mixture::VaporDiffusion
	VaporDiffusion ()

	VaporDiffusion (FuelCellShop::Material::PureGas &species1, FuelCellShop::Material::PureGas &species2)

virtual	~VaporDiffusion ()

Public Member Functions inherited from FuelCellShop::Mixture::BinaryDiffusion
	BinaryDiffusion ()

	BinaryDiffusion (FuelCellShop::Material::PureGas &species1, FuelCellShop::Material::PureGas &species2)

virtual	~BinaryDiffusion ()

void	set_T_and_p (const double &T, const double &p)
	Method used to set temperature (T) and pressure (p) for diffusion coefficient computation.

void	set_p (const double &p_atm)
	Method to set pressure (p) for isobaric diffusion coefficient case.

void	set_temperature (const FuelCellShop::SolutionVariable &T_vec)
	Method to set a vector of temperatures (T) for nonisothermal diffusion coefficient computation.

void	set_species (FuelCellShop::Material::PureGas &species1, FuelCellShop::Material::PureGas &species2)

Private Attributes
double	M_A

double	M_B

double	Tnb_A

double	Tnb_B

double	Vl_A

double	Vl_B

double	sikma_A

double	sikma_B

double	Tstar_A

double	Tstar_B

double	sikma_AB

double	Tstar_AB

double	omega_DAB

Additional Inherited Members
Protected Attributes inherited from FuelCellShop::Mixture::BinaryDiffusion
FuelCellShop::Material::PureGas *	species1

FuelCellShop::Material::PureGas *	species2

double	T
	Temperature [in K] used to compute the diffusion coefficient, unless specified as an input to the member function.

double	p
	Pressure [in atm] used to compute the diffusion coefficient, unless specified as an input to the member function.

FuelCellShop::SolutionVariable	T_vector
	Temperature [in K] used to compute the diffusion coefficient.

Detailed Description

This class uses the Chapman Enskog theory for mono-atomic gases to estimate the binary diffusion diffusivity between two gases.

The gases are input using the member function set_species(). Using member functions such as compute_diffusion() and compute_dD() the diffusion coefficient in units of m/s and the analytical derivatives of the diffusion coefficient with respect of temperature and pressure respectively can be obtained. Note that this class requires two objects of type FuelCellShop::Material::PureGas. In order to compute the binary diffusion coefficient for a gas that has not been implemented, a new child of FuelCellShop::Material::PureGas needs to be implemented with the properties specified in the base class obtained from experimental data or from the literature.

This class is publicly derived class of VaporDiffusion

Usage details

In order to use this class, you will need to specify the two gases for which you would like to compute the diffusion diffusion coefficient. For example, in the sample code below, we will compute the binary diffusion coefficient for oxygen in nitrogen. So, first we create an object oxygen and nitrogen gas from FuelCellShop::Material::PureGas. Then, we set these gases as the gases for which we will compute the coefficients. The diffusion coefficient is a function of temperature and pressure, therefore, we next set these values. The class takes these values in units of temperature [K] and pressure atm. Using compute_diffusion() the diffusion coefficient in units fo m2/s is returned. Note that the analytical derivatives of the diffusion coefficient with respect of temperature and pressure can also be obtained.

double Diff_coef(0);
FuelCellShop::Mixture::ChapmanEnskog CE;
FuelCellShop::Material::Oxygen O2;
FuelCellShop::Material::Nitrogen N2;
CE.set_species(O2,N2);
double temperature(353); //Temperature in K
double pressure(1); //Pressure in atm
CE.set_T_and_p(temperature,pressure);
CE.compute_diffusion(Diff_coef);
std::cout<<"Diffusion coeff: "<<Diff_coef<<" in m2/s"<<std::endl;

Author: A. MalekpourKoupaei and M. Secanell

Date: 2009-2013

Constructor & Destructor Documentation

FuelCellShop::Mixture::ChapmanEnskog::ChapmanEnskog ( )

FuelCellShop::Mixture::ChapmanEnskog::ChapmanEnskog	(	FuelCellShop::Material::PureGas &	species1,
		FuelCellShop::Material::PureGas &	species2
	)

virtual FuelCellShop::Mixture::ChapmanEnskog::~ChapmanEnskog ( )

virtual

Member Function Documentation

virtual void FuelCellShop::Mixture::ChapmanEnskog::compute_dD ( std::vector< double > & dD )

virtual

Implements FuelCellShop::Mixture::BinaryDiffusion.

virtual double FuelCellShop::Mixture::ChapmanEnskog::compute_dD_dP	(	const double &	T,
		const double &	p
	)

virtual

Implements FuelCellShop::Mixture::BinaryDiffusion.

virtual double FuelCellShop::Mixture::ChapmanEnskog::compute_dD_dT	(	const double &	T,
		const double &	p
	)

virtual

Implements FuelCellShop::Mixture::BinaryDiffusion.

virtual void FuelCellShop::Mixture::ChapmanEnskog::compute_dD_dT ( std::vector< double > & dD_dT_vec )

virtual

Method to compute derivative of diffusion coefficient with respect to temperature [in m^2/(s-K)] for a non-isothermal, isobaric case, at all quadrature points of the cell.

To specify temperatures, use the member function #set_T_vector and to specify pressure, use the member function set_p. The given temperatures and pressure should be in Kelvin and atmospheres.

Implements FuelCellShop::Mixture::BinaryDiffusion.

virtual void FuelCellShop::Mixture::ChapmanEnskog::compute_diffusion ( double & D )

virtual

Comupute the diffusion coefficient [in m^2/s] at a given temperature [K] and pressure [atm].

To specify tempertaure and pressure use the member function set_T_and_p(). The given temperature and pressure should be in Kelvin and atmospheres.

Implements FuelCellShop::Mixture::BinaryDiffusion.

virtual void FuelCellShop::Mixture::ChapmanEnskog::compute_diffusion ( std::vector< double > & D_vec )

virtual

Compute a vector of diffusion coefficients [in m^2/s] for a non-isothermal, isobaric case.

To specify temperatures, use the member function set_T_vector and to specify pressure, use the member function set_p. The given temperatures and pressure should be in Kelvin and atmospheres.

Implements FuelCellShop::Mixture::BinaryDiffusion.

virtual double FuelCellShop::Mixture::ChapmanEnskog::compute_diffusion	(	const double &	T,
		const double &	p
	)

virtual

Comupute the diffusion coefficient [in m^2/s] at a given temperature [K] and pressure [atm].

Implements FuelCellShop::Mixture::BinaryDiffusion.

virtual void FuelCellShop::Mixture::ChapmanEnskog::compute_diffusion	(	double &	D,
		std::vector< double > &	dD
	)

virtual

Comupute diffusion coefficient [in m^2/s] and the sensitivity of the diffusion coefficient with respect to temperature and pressure.

To specify tempertaure and pressure use the member function set_T_and_p(). The given temperature and pressure should be in Kelvin and atmospheres

Implements FuelCellShop::Mixture::BinaryDiffusion.

virtual void FuelCellShop::Mixture::ChapmanEnskog::compute_diffusion	(	const double &	T,
		const double &	p,
		double &	D,
		std::vector< double > &	dD
	)

virtual

Comupute diffusion coefficient [in m^2/s] and the sensitivity of the diffusion coefficient with respect to temperature and pressure at a given temperature [K] and pressure [atm].

Implements FuelCellShop::Mixture::BinaryDiffusion.

virtual char* FuelCellShop::Mixture::ChapmanEnskog::get_description ( )

virtual

Implements FuelCellShop::Mixture::BinaryDiffusion.

virtual enDiffusionModelID FuelCellShop::Mixture::ChapmanEnskog::get_ID ( )

virtual

Implements FuelCellShop::Mixture::BinaryDiffusion.

virtual char* FuelCellShop::Mixture::ChapmanEnskog::get_name ( )

virtual

Implements FuelCellShop::Mixture::BinaryDiffusion.

virtual double FuelCellShop::Mixture::ChapmanEnskog::getOmegaAB ( const double & Tstar )

virtual