Gross.cpp File Reference

Implementation of AGA 8 Part 1 GROSS equation of state (Version 2.0) More...

#include "Gross.h"
#include <math.h>
#include <cmath>
#include <iostream>
#include <cstdlib>

Include dependency graph for Gross.cpp:

Go to the source code of this file.

Functions
void	Bmix (const double T, const std::vector< double > &xGrs, const double HCH, double &B, double &C, int &ierr, std::string &herr)
	Calculate 2nd and 3rd virial coefficients for the mixture at T.
void	MolarMassGross (const std::vector< double > &x, double &Mm)
	Calculate molar mass of the mixture with the compositions contained in the x() input array.
void	PressureGross (const double T, const double D, const std::vector< double > &xGrs, const double HCH, double &P, double &Z, int &ierr, std::string &herr)
	Calculate pressure as a function of temperature and density.
void	DensityGross (const double T, const double P, const std::vector< double > &xGrs, const double HCH, double &D, int &ierr, std::string &herr)
	Calculate density as a function of temperature and pressure.
void	GrossHv (const std::vector< double > &x, std::vector< double > &xGrs, double &HN, double &HCH)
	Calculate ideal heating values based on composition.
void	GrossInputs (const double T, const double P, const std::vector< double > &x, std::vector< double > &xGrs, double &Gr, double &HN, double &HCH, int &ierr, std::string &herr)
	Calculate relative density and heating values based on composition.
void	SetupGross ()
	Initialize all the constants and parameters in the GROSS model.
void	GrossMethod1 (const double Th, const double Td, const double Pd, std::vector< double > &xGrs, const double Gr, const double Hv, double &Mm, double &HCH, double &HN, int &ierr, std::string &herr)
	Initialize variables required in the GROSS equation with Method 1 of the AGA 8 Part 1 publication.
void	GrossMethod2 (const double Th, const double Td, const double Pd, std::vector< double > &xGrs, const double Gr, double &Hv, double &Mm, double &HCH, double &HN, int &ierr, std::string &herr)
	Initialize variables required in the GROSS equation with Method 2 of the AGA 8 Part 1 publication.

Variables
static double	RGross
static const int	NcGross = 21
static const int	MaxFlds = 21
static const double	epsilon = 1e-15
static double	mN2
static double	mCO2
static double	dPdDsave
static double	xHN [MaxFlds+1]
static double	MMiGross [MaxFlds+1]
static double	b0 [4][4]
static double	b1 [4][4]
static double	b2 [4][4]
static double	bCHx [3][3]
static double	cCHx [3][3]
static double	c0 [4][4][4]
static double	c1 [4][4][4]
static double	c2 [4][4][4]

Detailed Description

Implementation of AGA 8 Part 1 GROSS equation of state (Version 2.0)

This code implements routines for the calculation of thermodynamic properties from the AGA 8 Part 1 GROSS equation of state (April 2017).

The GROSS method is used for natural gas mixtures and requires less detailed composition information than the DETAIL method. It can use either:

• Method 1: volumetric gross heating value, relative density, and mole fraction of CO2
• Method 2: relative density and mole fractions of nitrogen and CO2

Component order for composition array: 1 - Methane 8 - Isopentane 15 - Hydrogen 2 - Nitrogen 9 - n-Pentane 16 - Oxygen 3 - Carbon dioxide 10 - n-Hexane 17 - Carbon monoxide 4 - Ethane 11 - n-Heptane 18 - Water 5 - Propane 12 - n-Octane 19 - Hydrogen sulfide 6 - Isobutane 13 - n-Nonane 20 - Helium 7 - n-Butane 14 - n-Decane 21 - Argon

Note

SetupGross() must be called once before using any other routines

Author

Eric W. Lemmon (NIST)

Ian H. Bell (NIST)

Volker Heinemann (RMG Messtechnik GmbH)

Jason Lu (Thermo Fisher Scientific)

Copyright

Public domain (NIST)

Definition in file Gross.cpp.

Function Documentation

Bmix()

void Bmix	(	const double	T,
		const std::vector< double > &	xGrs,
		const double	HCH,
		double &	B,
		double &	C,
		int &	ierr,
		std::string &	herr )

Calculate 2nd and 3rd virial coefficients for the mixture at T.

Parameters

	T	Temperature (K)
	xGrs	Compositions of the equivalent hydrocarbon, nitrogen, and CO2 (mole fractions)
	HCH	Molar ideal gross heating value of the equivalent hydrocarbon (kJ/mol) at 298.15 K
[out]	B	Second virial coefficient (dm^3/mol)
[out]	C	Third virial coefficient (dm^6/mol^2)
[out]	ierr	Error number (0 indicates no error)
[out]	herr	Error message if ierr is not equal to zero

See also

Bmix_wrapper for the Emscripten wrapper

Definition at line 412 of file Gross.cpp.

{
    // Sub Bmix(T, xGrs, HCH, B, C, ierr, herr)
 
    // Calculate 2nd and 3rd virial coefficients for the mixture at T.
 
    // Inputs:
    //      T - Temperature (K)
    //   xGrs - Compositions of the equivalent hydrocarbon, nitrogen, and CO2 (mole fractions)
    //    HCH - Molar ideal gross heating value of the equivalent hydrocarbon (kJ/mol) at 298.15 K
 
    // Outputs:
    //      B - Second virial coefficient (dm^3/mol)
    //      C - Third virial coefficient (dm^6/mol^2)
    //   ierr - Error number (0 indicates no error)
    //   herr - Error message if ierr is not equal to zero
 
    double bCH[3], cCH[3], BB[4][4], CC[4][4][4];
    const double onethrd = 1.0 / 3.0;
 
    ierr = 0;
    herr = "";
    B = 0;
    C = 0;
 
    // Temperature dependent Bi and Ci values for obtaining B(CH-CH) and C(CH-CH-CH)
    for (int i = 0; i <= 2; ++i){
        bCH[i] = bCHx[0][i] + bCHx[1][i]*T + bCHx[2][i]*pow(T, 2);
        cCH[i] = cCHx[0][i] + cCHx[1][i]*T + cCHx[2][i]*pow(T, 2);
    }
 
    // Bij and Cijk values for nitrogen and CO2
    for(int i = 2; i <= 3; ++i){
        for(int j = i; j <= 3; ++j){
            BB[i][j] = b0[i][j] + b1[i][j] * T + b2[i][j]*pow(T, 2);
            for(int k = j; k <= 3; ++k){
                CC[i][j][k] = c0[i][j][k] + c1[i][j][k] * T + c2[i][j][k]*pow(T, 2);
            }
        }
    }
 
    // Bij values for use in calculating Bmix
    BB[1][1] = bCH[0] + bCH[1]*HCH + bCH[2]*pow(HCH, 2); // B(CH-CH) for the equivalent hydrocarbon
    BB[1][2] = (0.72 + 0.00001875 * pow(320 - T, 2))*(BB[1][1] + BB[2][2])/2.0; // B(CH-N2)
    if (BB[1][1]*BB[3][3] < 0){
        ierr = 4; herr = "Invalid input in Bmix routine";
        return;
    }
    BB[1][3] = -0.865 * sqrt(BB[1][1] * BB[3][3]); // B(CH-CO2)
 
    // Cijk values for use in calculating Cmix
    CC[1][1][1] = cCH[0] + cCH[1] * HCH + cCH[2] * pow(HCH, 2); // C(CH-CH-CH) for the equivalent hydrocarbon
    if (CC[1][1][1] < 0 || CC[3][3][3] < 0){
        ierr = 5; herr = "Invalid input in Bmix routine";
        return;
    }
    CC[1][1][2] = (0.92 + 0.0013 * (T - 270)) * pow(pow(CC[1][1][1], 2) * CC[2][2][2], onethrd); // C(CH-CH-N2)
    CC[1][2][2] = (0.92 + 0.0013 * (T - 270)) * pow(pow(CC[2][2][2], 2) * CC[1][1][1], onethrd); // C(CH-N2-N2)
    CC[1][1][3] = 0.92 * pow(pow(CC[1][1][1], 2) * CC[3][3][3], onethrd); // C(CH-CH-CO2)
    CC[1][3][3] = 0.92 * pow(pow(CC[3][3][3], 2) * CC[1][1][1], onethrd); // C(CH-CO2-CO2)
    CC[1][2][3] = 1.1 * pow(CC[1][1][1] * CC[2][2][2] * CC[3][3][3], onethrd); // C(CH-N2-CO2)
 
    // Calculate Bmix and Cmix
    for (std::size_t i = 1; i <= 3; ++i){
        for(std::size_t j = i; j <= 3; ++j){
            if (i == j){
                B += BB[i][i]*pow(xGrs[i], 2);
            }
            else{
                B += 2*BB[i][j]*xGrs[i]*xGrs[j];
            }
            for(std::size_t k = j; k <= 3; ++k){
                if (i == j && j == k) {
                    C += CC[i][i][i]*pow(xGrs[i], 3);
                }
                else if (i != j && j != k && i != k){
                    C += 6*CC[i][j][k]*xGrs[i]*xGrs[j]*xGrs[k];
                }
                else{
                    C += 3*CC[i][j][k]*xGrs[i]*xGrs[j]*xGrs[k];
                }
            }
        }
    }
}

References b0, b1, b2, bCHx, c0, c1, c2, and cCHx.

Referenced by Bmix_wrapper(), GrossMethod1(), GrossMethod2(), and PressureGross().

DensityGross()

void DensityGross	(	const double	T,
		const double	P,
		const std::vector< double > &	xGrs,
		const double	HCH,
		double &	D,
		int &	ierr,
		std::string &	herr )

Calculate density as a function of temperature and pressure.

This is an iterative routine that calls PressureGross to find the correct state point. Generally only 6 iterations at most are required. If the iteration fails to converge, the ideal gas density and an error message are returned.

Parameters

	T	Temperature (K)
	P	Pressure (kPa)
	xGrs	Compositions of the equivalent hydrocarbon, nitrogen, and CO2 (mole fractions)
	HCH	Molar ideal gross heating value of the hydrocarbon components (kJ/mol) at 298.15 K. Call subroutine GrossHv or GrossInputs first to obtain HCH.
[out]	D	Density (mol/l)
[out]	ierr	Error number (0 indicates no error)
[out]	herr	Error message if ierr is not equal to zero

See also

DensityGross_wrapper for the Emscripten wrapper

Definition at line 236 of file Gross.cpp.

{
    // Sub DensityGross(T, P, xGrs, HCH, D, ierr, herr)
    //
    // Calculate density as a function of temperature and pressure.  This is an iterative routine that calls PressureGross
    // to find the correct state point.  Generally only 6 iterations at most are required.
    // If the iteration fails to converge, the ideal gas density and an error message are returned.
    //
    // Inputs:
    //      T - Temperature (K)
    //      P - Pressure (kPa)
    //   xGrs - Compositions of the equivalent hydrocarbon, nitrogen, and CO2 (mole fractions)
    //    HCH - Molar ideal gross heating value of the hydrocarbon components (kJ/mol) at 298.15 K
    //          *** Call subroutine GrossHv or GrossInputs first to obtain HCH. ***
    //
    // Outputs:
    //      D - Density (mol/l)
    //   ierr - Error number (0 indicates no error)
    //   herr - Error message if ierr is not equal to zero
 
    double plog, vlog, P2, Z, dpdlv, vdiff, tolr;
 
    ierr = 0;
    herr = "";
    if (P < epsilon){
        D = 0; return;
    } 
    tolr = 0.0000001;
    D = P / RGross / T;       //Ideal gas estimate
    plog = log(P);
    vlog = -log(D);
    for(int it = 1; it <= 20; ++it){
        if(vlog < -7 || vlog > 100){
            ierr = 1;
            herr = "Calculation failed to converge in GROSS method, ideal gas density returned.";
            D = P/RGross/T;
            return;
        }
        D = exp(-vlog);
        PressureGross(T, D, xGrs, HCH, P2, Z, ierr, herr);
        if (ierr > 0){ return; }
        if(dPdDsave < epsilon || P2 < epsilon){
            vlog += 0.1;
        }
        else{
            // Find the next density with a first order Newton's type iterative scheme, with
            // log(P) as the known variable and log(v) as the unknown property.
            // See AGA 8 publication for further information.
            dpdlv = -D * dPdDsave;     // d(p)/d[log(v)]
            vdiff = (log(P2) - plog) * P2 / dpdlv;
            vlog = vlog - vdiff;
            if (std::abs(vdiff) < tolr){
                if (P2 < 0){
                    ierr = 10;
                    herr = "Calculation failed to converge in the GROSS method, ideal gas density returned.";
                    D = P/RGross/T;
                    return;
                }
                // Iteration converged
                D = exp(-vlog);
                return;
            }
        }
    }
    ierr = 10;
    herr = "Calculation failed to converge in the GROSS method, ideal gas density returned.";
    D = P/RGross/T;
}

References dPdDsave, epsilon, PressureGross(), and RGross.

Referenced by DensityGross_wrapper(), and GrossInputs().

GrossHv()

void GrossHv	(	const std::vector< double > &	x,
		std::vector< double > &	xGrs,
		double &	HN,
		double &	HCH )

Calculate ideal heating values based on composition.

The mole fractions in the mixture are required in this routine, not just xCH, xN2, and xCO2.

Parameters

	x	Molar compositions of all components in the mixture. The order in this array is given at the top of this code.
[out]	xGrs	Compositions of the equivalent hydrocarbon, nitrogen, and CO2 (mole fractions)
[out]	HN	Molar ideal gross heating value of the mixture (kJ/mol) at 298.15 K
[out]	HCH	Molar ideal gross heating value of the equivalent hydrocarbon (kJ/mol) at 298.15 K

See also

GrossHv_wrapper for the Emscripten wrapper

Definition at line 317 of file Gross.cpp.

{
    // Sub GrossHv(x, xGrs, HN, HCH)
    //
    // Calculate ideal heating values based on composition.  The mole fractions in the mixture are required in this routine, not
    //   just xCH, xN2, and xCO2.
    //
    // Inputs:
    //     x - Molar compositions of all components in the mixture.  The order in this array is given at the top of this code.
    //
    // Outputs:
    //  xGrs - Compositions of the equivalent hydrocarbon, nitrogen, and CO2 (mole fractions)
    //    HN - Molar ideal gross heating value of the mixture (kJ/mol) at 298.15 K
    //   HCH - Molar ideal gross heating value of the equivalent hydrocarbon (kJ/mol) at 298.15 K
    xGrs.resize(4);
    xGrs[1] = 1 - x[2] - x[3];
    xGrs[2] = x[2];
    xGrs[3] = x[3];
    HN = 0;
    for(std::size_t i = 1; i <= NcGross; ++i){
        HN += x[i]*xHN[i];
    }
    HCH = 0;
    if (xGrs[1] > 0){
        HCH = HN / xGrs[1];
    }
}

References NcGross, and xHN.

Referenced by GrossHv_wrapper(), and GrossInputs().

GrossInputs()

void GrossInputs	(	const double	T,
		const double	P,
		const std::vector< double > &	x,
		std::vector< double > &	xGrs,
		double &	Gr,
		double &	HN,
		double &	HCH,
		int &	ierr,
		std::string &	herr )

Calculate relative density and heating values based on composition.

This routine should only be used to get these two values for use as inputs to Method 1 or Method 2, and not for the relative density for any T and P. All of the mole fractions in the mixture are required in this routine, not just xCH, xN2, and xCO2.

Parameters

	T	Temperature (K), generally a reference temperature for relative density
	P	Pressure (kPa), generally a reference pressure for relative density
	x	Molar compositions of all components in the mixture. The order in this array is given at the top of this code.
[out]	xGrs	Compositions of the equivalent hydrocarbon, nitrogen, and CO2 (mole fractions)
[out]	Gr	Relative density at T and P
[out]	HN	Molar ideal gross heating value of the mixture (kJ/mol) at 298.15 K
[out]	HCH	Molar ideal gross heating value of the equivalent hydrocarbon (kJ/mol) at 298.15 K
[out]	ierr	Error number (0 indicates no error)
[out]	herr	Error message if ierr is not equal to zero

See also

GrossInputs_wrapper for the Emscripten wrapper

Definition at line 364 of file Gross.cpp.

{
    // Sub GrossInputs(T, P, x, xGrs, Gr, HN, HCH, ierr, herr)
 
    // Calculate relative density and heating values based on composition.  This routine should only be used to get these
    //   two values for use as inputs to Method 1 or Method 2, and not for the relative density for any T and P.
    //   All of the mole fractions in the mixture are required in this routine, not just xCH, xN2, and xCO2.
 
    // Inputs:
    //      T - Temperature (K), generally a reference temperature for relative density
    //      P - Pressure (kPa), generally a reference pressure for relative density
    //      x - Molar compositions of all components in the mixture.  The order in this array is given at the top of this code.
 
    // Outputs:
    //   xGrs - Compositions of the equivalent hydrocarbon, nitrogen, and CO2 (mole fractions)
    //     Gr - Relative density at T and P
    //     HN - Molar ideal gross heating value of the mixture (kJ/mol) at 298.15 K
    //    HCH - Molar ideal gross heating value of the equivalent hydrocarbon (kJ/mol) at 298.15 K
    //   ierr - Error number (0 indicates no error)
    //   herr - Error message if ierr is not equal to zero
 
    double Bref, Zref, Mref, Z, D, Mm;
    xGrs.resize(4);
    ierr = 0;
    herr = "";
    GrossHv(x, xGrs, HN, HCH);
    Bref = -0.12527 + 0.000591*T - 0.000000662*pow(T, 2);   // 2nd virial coefficient of the reference fluid at T
    Zref = 1 + Bref*P/RGross/T;                             // Z of the reference fluid at T and P
    Mref = 28.9625;
    MolarMassGross(x, Mm);
 
    DensityGross(T, P, xGrs, HCH, D, ierr, herr);           // Density of the input fluid at T and D
    Z = P / T / D / RGross;                                 // Z of the input fluid at T and D
    Gr = Mm * Zref / Mref / Z;
}

References DensityGross(), GrossHv(), MolarMassGross(), and RGross.

Referenced by GrossInputs_wrapper().

GrossMethod1()

void GrossMethod1	(	const double	Th,
		const double	Td,
		const double	Pd,
		std::vector< double > &	xGrs,
		const double	Gr,
		const double	Hv,
		double &	Mm,
		double &	HCH,
		double &	HN,
		int &	ierr,
		std::string &	herr )

Initialize variables required in the GROSS equation with Method 1 of the AGA 8 Part 1 publication.

Method 1 requires inputs of volumetric gross heating value, relative density, and mole fraction of CO2.

Parameters

	Th	Reference temperature for heating value (K)
	Td	Reference temperature for density (K)
	Pd	Reference pressure for density (kPa)
	xGrs	Array of size 3 with the molar composition of CO2 in the 3rd position. xCH and xN2 are returned in this array.
	Gr	Relative density at Td and Pd
	Hv	Volumetric ideal gross heating value (MJ/m^3) at Th
[out]	Mm	Molar mass (g/mol)
[out]	HCH	Molar ideal gross heating value of the equivalent hydrocarbon (kJ/mol) at 298.15 K
[out]	HN	Molar ideal gross heating value of the mixture (kJ/mol) at 298.15 K
[out]	ierr	Error number (0 indicates no error)
[out]	herr	Error message if ierr is not equal to zero

See also

GrossMethod1_wrapper for the Emscripten wrapper

Definition at line 517 of file Gross.cpp.

{
    // Sub GrossMethod1(Th, Td, Pd, xGrs, Gr, Hv, Mm, HCH, HN, ierr, herr)
 
    // Initialize variables required in the GROSS equation with Method 1 of the AGA 8 Part 1 publication.
    // Method 1 requires inputs of volumetric gross heating value, relative density, and mole fraction of CO2.
    // 
    // Inputs:
    //     Th - Reference temperature for heating value (K)
    //     Td - Reference temperature for density (K)
    //     Pd - Reference pressure for density (kPa)
    //   xGrs - Array of size 3 with the molar composition of CO2 in the 3rd position.  xCH and xN2 are returned in this array.
    //     Gr - Relative density at Td and Pd
    //     Hv - Volumetric ideal gross heating value (MJ/m^3) at Th
    // 
    // Outputs:
    //   xGrs - Compositions of the equivalent hydrocarbon, nitrogen, and CO2 (mole fractions)
    //     Mm - Molar mass (g/mol)
    //    HCH - Molar ideal gross heating value of the equivalent hydrocarbon (kJ/mol) at 298.15 K
    //     HN - Molar ideal gross heating value of the mixture (kJ/mol) at 298.15 K
    //   ierr - Error number (0 indicates no error)
    //   herr - Error message if ierr is not equal to zero
 
    double xCH, xN2, xCO2, Zd, Zold, G1, G2, Bref, Zref, B, C;
 
    ierr = 0;
    herr = "";
    if (Gr < epsilon){ierr = 1; herr = "Invalid input for relative density"; return;}
    if (Hv < epsilon){ierr = 2; herr = "Invalid input for heating value"; return;}
 
    xCO2 = xGrs[3];
    Zd = 1;
    G1 = -2.709328;
    G2 = 0.021062199;
    Bref = -0.12527 + 0.000591*Td - 0.000000662*pow(Td, 2);              // [dm^3/mol]
    Zref = (1 + Pd / RGross / Td * Bref);
    for (int i = 0; i < 20; ++i){
        Zold = Zd;
        HN = Zd*RGross*Td/Pd*Hv*(1 + 0.0001027*(Th - 298.15));          // [kJ/mol] at 25 C
        Mm = Gr*Zd*28.9625 / Zref;                                     // [g/mol]
        xCH = (Mm + (xCO2 - 1) * mN2 - xCO2 * mCO2 - G2 * HN) / (G1 - mN2);
        xN2 = 1 - xCH - xCO2;
        if (xN2 < 0){
            ierr = 3; herr = "Negative nitrogen value in GROSS method 1 setup";
            return;
        }
        HCH = HN / xCH;
        xGrs[1] = xCH;
        xGrs[2] = xN2;
        Bmix(Td, xGrs, HCH, B, C, ierr, herr);
        if (ierr > 0){
            return;
        } 
        Zd = 1 + B*Pd/RGross/Td;
        if(std::abs(Zold - Zd) < 0.0000001) { break; }
    }
}

References Bmix(), epsilon, mCO2, mN2, and RGross.

Referenced by GrossMethod1_wrapper().

GrossMethod2()

void GrossMethod2	(	const double	Th,
		const double	Td,
		const double	Pd,
		std::vector< double > &	xGrs,
		const double	Gr,
		double &	Hv,
		double &	Mm,
		double &	HCH,
		double &	HN,
		int &	ierr,
		std::string &	herr )

Initialize variables required in the GROSS equation with Method 2 of the AGA 8 Part 1 publication.

Method 2 requires inputs of relative density and mole fractions of nitrogen and CO2.

Parameters

	Th	Reference temperature for heating value (K)
	Td	Reference temperature for density (K)
	Pd	Reference pressure for density (kPa)
	xGrs	Array of size 3 with the molar composition of N2 in the 2nd position and CO2 in the 3rd position. xCH is returned in this array.
	Gr	Relative density at Td and Pd
[out]	Hv	Volumetric ideal gross heating value (MJ/m^3) at Th
[out]	Mm	Molar mass (g/mol)
[out]	HCH	Molar ideal gross heating value of the equivalent hydrocarbon (kJ/mol) at 298.15 K
[out]	HN	Molar ideal gross heating value of the mixture (kJ/mol) at 298.15 K
[out]	ierr	Error number (0 indicates no error)
[out]	herr	Error message if ierr is not equal to zero

See also

GrossMethod2_wrapper for the Emscripten wrapper

Definition at line 594 of file Gross.cpp.

{
    // Sub GrossMethod2(Th, Td, Pd, xGrs, Gr, Hv, Mm, HCH, HN, ierr, herr)
 
    // Initialize variables required in the GROSS equation with Method 2 of the AGA 8 Part 1 publication.
    // Method 2 requires inputs of relative density and mole fractions of nitrogen and CO2.
    // 
    // Inputs:
    //     Th - Reference temperature for heating value (K)
    //     Td - Reference temperature for density (K)
    //     Pd - Reference pressure for density (kPa)
    //   xGrs - Array of size 3 with the molar composition of N2 in the 2nd position and CO2 in the 3rd position.  xCH is returned in this array.
    //     Gr - Relative density at Td and Pd
    // 
    // Outputs:
    //   xGrs - Compositions of the equivalent hydrocarbon, nitrogen, and CO2 (mole fractions)
    //     Hv - Volumetric ideal gross heating value (MJ/m^3) at Th
    //     Mm - Molar mass (g/mol)
    //    HCH - Molar ideal gross heating value of the equivalent hydrocarbon (kJ/mol) at 298.15 K
    //     HN - Molar ideal gross heating value of the mixture (kJ/mol) at 298.15 K
    //   ierr - Error number (0 indicates no error)
    //   herr - Error message if ierr is not equal to zero
 
    double xCH, Z, Zold, Bref, Zref, MrCH, G1, G2, B, C, xN2, xCO2;
    ierr = 0;
    herr = "";
    if (Gr < epsilon){ ierr = 1; herr = "Invalid input for relative density"; return; }
 
    xN2 = xGrs[2];
    xCO2 = xGrs[3];
    xCH = 1 - xN2 - xCO2;
    xGrs[1] = xCH;
    Z = 1;
    G1 = -2.709328;
    G2 = 0.021062199;
    Bref = -0.12527 + 0.000591*Td - 0.000000662*pow(Td, 2);
    Zref = (1 + Pd / RGross / Td * Bref);
    for (int i = 0; i < 20; ++i){
        Zold = Z;
        Mm = Gr*Z*28.9625/Zref;
        MrCH = (Mm - xN2 * mN2 - xCO2 * mCO2)/xCH;
        HCH = (MrCH - G1) / G2;
        Bmix(Td, xGrs, HCH, B, C, ierr, herr);
        if (ierr > 0){ return; }
        Z = 1 + B * Pd / RGross / Td;
        if (std::abs(Zold - Z) < 0.0000001){ break; };
    }
    HN = HCH * xCH;
    Hv = HN / Z / RGross / Td * Pd / (1 + 0.0001027 * (Th - 298.15));
}

References Bmix(), epsilon, mCO2, mN2, and RGross.

Referenced by GrossMethod2_wrapper().

MolarMassGross()

void MolarMassGross	(	const std::vector< double > &	x,
		double &	Mm )

Calculate molar mass of the mixture with the compositions contained in the x() input array.

Parameters

x	Composition array (mole fraction) Do not send mole percents or mass fractions in the x() array, otherwise the output will be incorrect. The sum of the compositions in the x() array must be equal to one. The order of the fluids in this array is given at the top of this code.
Mm	[out] Molar mass (g/mol)

See also

MolarMassGross_wrapper for the Emscripten wrapper

Definition at line 143 of file Gross.cpp.

{
// Sub MolarMassGross(x, Mm)
 
// Calculate molar mass of the mixture with the compositions contained in the x() input array
 
// Inputs:
//    x() - Composition (mole fraction)
//          Do not send mole percents or mass fractions in the x() array, otherwise the output will be incorrect.
//          The sum of the compositions in the x() array must be equal to one.
//          The order of the fluids in this array is given at the top of this code.
 
// Outputs:
//     Mm - Molar mass (g/mol)
 
  Mm = 0;
  for(std::size_t i = 1; i <= NcGross; ++i){
    Mm += x[i] * MMiGross[i];
  }
}

References MMiGross, and NcGross.

Referenced by GrossInputs(), and MolarMassGross_wrapper().

PressureGross()

void PressureGross	(	const double	T,
		const double	D,
		const std::vector< double > &	xGrs,
		const double	HCH,
		double &	P,
		double &	Z,
		int &	ierr,
		std::string &	herr )

Calculate pressure as a function of temperature and density.

The derivative d(P)/d(D) is also calculated for use in the iterative DensityGross subroutine (and is only returned as a common variable).

Parameters

	T	Temperature (K)
	D	Density (mol/l)
	xGrs	Compositions of the equivalent hydrocarbon, nitrogen, and CO2 (mole fractions)
	HCH	Molar ideal gross heating value of the equivalent hydrocarbon (kJ/mol) at 298.15 K. Call subroutine GrossHv or GrossInputs first to obtain HCH.
[out]	P	Pressure (kPa)
[out]	Z	Compressibility factor
[out]	ierr	Error number (0 indicates no error)
[out]	herr	Error message if ierr is not equal to zero

Note

dPdDsave - d(P)/d(D) [kPa/(mol/l)] (at constant temperature) This variable is cached in the common variables for use in the iterative density solver

See also

PressureGross_wrapper for the Emscripten wrapper

Definition at line 183 of file Gross.cpp.

{
    // Sub PressureGross(T, D, xGrs, HCH, P, Z, ierr, herr)
    //
    // Calculate pressure as a function of temperature and density.  The derivative d(P)/d(D) is also calculated
    // for use in the iterative DensityGross subroutine (and is only returned as a common variable).
    // 
    // Inputs:
    //      T - Temperature (K)
    //      D - Density (mol/l)
    //   xGrs - Compositions of the equivalent hydrocarbon, nitrogen, and CO2 (mole fractions)
    //    HCH - Molar ideal gross heating value of the equivalent hydrocarbon (kJ/mol) at 298.15 K
    //          *** Call subroutine GrossHv or GrossInputs first to obtain HCH. ***
    // 
    // Outputs:
    //      P - Pressure (kPa)
    //      Z - Compressibility factor
    //   ierr - Error number (0 indicates no error)
    //   herr - Error message if ierr is not equal to zero
    //   dPdDsave - d(P)/d(D) [kPa/(mol/l)] (at constant temperature)
    //            - This variable is cached in the common variables for use in the iterative density solver, but not returned as an argument.
 
    double B = 1e30, C = 1e30;
    Z = 1;
    P = D*RGross*T;
    Bmix(T, xGrs, HCH, B, C, ierr, herr);
    if (ierr > 0) { return; }
    Z = 1 + B*D + C*pow(D, 2);
    P = D*RGross*T*Z;
    dPdDsave = RGross*T*(1 + 2*B*D + 3*C*D*D);
    if (P < 0){
        ierr = -1;
        herr = "Pressure is negative in the GROSS method.";
    }
}

References Bmix(), dPdDsave, and RGross.

Referenced by DensityGross(), and PressureGross_wrapper().

SetupGross()

void SetupGross

(

)

Initialize all the constants and parameters in the GROSS model.

This routine must be called once before any other routine.

Note

this function is directly wrapped to SetupGross() function in Emscripten

Definition at line 651 of file Gross.cpp.

{
  // Initialize all the constants and parameters in the GROSS model.
  RGross = 8.31451;
 
  // Molar masses (g/mol).  These are the same as those in the DETAIL method.
  MMiGross[1] = 16.043;    // Methane
  MMiGross[2] = 28.0135;   // Nitrogen
  MMiGross[3] = 44.01;     // Carbon dioxide
  MMiGross[4] = 30.07;     // Ethane
  MMiGross[5] = 44.097;    // Propane
  MMiGross[6] = 58.123;    // Isobutane
  MMiGross[7] = 58.123;    // n-Butane
  MMiGross[8] = 72.15;     // Isopentane
  MMiGross[9] = 72.15;     // n-Pentane
  MMiGross[10] = 86.177;   // Hexane
  MMiGross[11] = 100.204;  // Heptane
  MMiGross[12] = 114.231;  // Octane
  MMiGross[13] = 128.258;  // Nonane
  MMiGross[14] = 142.285;  // Decane
  MMiGross[15] = 2.0159;   // Hydrogen
  MMiGross[16] = 31.9988;  // Oxygen
  MMiGross[17] = 28.01;    // Carbon monoxide
  MMiGross[18] = 18.0153;  // Water
  MMiGross[19] = 34.082;   // Hydrogen sulfide
  MMiGross[20] = 4.0026;   // Helium
  MMiGross[21] = 39.948;   // Argon
 
  //Initialize constants
  b0[2][2] = -0.1446;           b1[2][2] = 0.00074091;         b2[2][2] = -0.00000091195;
  b0[2][3] = -0.339693;         b1[2][3] = 0.00161176;         b2[2][3] = -0.00000204429;
  b0[3][3] = -0.86834;          b1[3][3] = 0.0040376;          b2[3][3] = -0.0000051657;
  c0[2][2][2] = 0.0078498;      c1[2][2][2] = -0.000039895;    c2[2][2][2] = 0.000000061187;
  c0[2][2][3] = 0.00552066;     c1[2][2][3] = -0.0000168609;   c2[2][2][3] = 0.0000000157169;
  c0[2][3][3] = 0.00358783;     c1[2][3][3] = 0.00000806674;   c2[2][3][3] = -0.0000000325798;
  c0[3][3][3] = 0.0020513;      c1[3][3][3] = 0.000034888;     c2[3][3][3] = -0.000000083703;
  bCHx[0][0] = -0.425468;       bCHx[1][0] = 0.002865;         bCHx[2][0] = -0.00000462073;
  bCHx[0][1] = 0.000877118;     bCHx[1][1] = -0.00000556281;   bCHx[2][1] = 0.0000000088151;
  bCHx[0][2] = -0.000000824747; bCHx[1][2] = 0.00000000431436; bCHx[2][2] = -6.08319E-12;
  cCHx[0][0] = -0.302488;       cCHx[1][0] = 0.00195861;       cCHx[2][0] = -0.00000316302;
  cCHx[0][1] = 0.000646422;     cCHx[1][1] = -0.00000422876;   cCHx[2][1] = 0.00000000688157;
  cCHx[0][2] = -0.000000332805; cCHx[1][2] = 0.0000000022316;  cCHx[2][2] = -3.67713E-12;
 
  // //Heating values from ISO 6976 at 25 C (kJ/mol)
  // 'xHN(1) = 890.58    'Methane
  // 'xHN(2) = 0         'Nitrogen
  // 'xHN(3) = 0         'Carbon dioxide
  // 'xHN(4) = 1560.69   'Ethane
  // 'xHN(5) = 2219.17   'Propane
  // 'xHN(6) = 2868.2    'Isobutane
  // 'xHN(7) = 2877.4    'n-Butane
  // 'xHN(8) = 3528.83   'Isopentane
  // 'xHN(9) = 3535.77   'n-Pentane
  // 'xHN(10) = 4194.95  'Hexane
  // 'xHN(11) = 4853.43  'Heptane
  // 'xHN(12) = 5511.8   'Octane
  // 'xHN(13) = 6171.15  'Nonane
  // 'xHN(14) = 6829.77  'Decane
  // 'xHN(15) = 285.83   'Hydrogen
  // 'xHN(16) = 0        'Oxygen
  // 'xHN(17) = 282.98   'Carbon monoxide
  // 'xHN(18) = 44.013   'Water
  // 'xHN(19) = 562.01   'Hydrogen sulfide
  // 'xHN(20) = 0        'Helium
  // 'xHN(21) = 0        'Argon
 
  // Heating values from AGA-5, 2009 at 25 C (kJ/mol)
  xHN[1] = 890.63;     // Methane
  xHN[2] = 0;          // Nitrogen
  xHN[3] = 0;          // Carbon dioxide
  xHN[4] = 1560.69;    // Ethane
  xHN[5] = 2219.17;    // Propane
  xHN[6] = 2868.2;     // Isobutane
  xHN[7] = 2877.4;     // n-Butane
  xHN[8] = 3528.83;    // Isopentane
  xHN[9] = 3535.77;    // n-Pentane
  xHN[10] = 4194.95;   // Hexane
  xHN[11] = 4853.43;   // Heptane
  xHN[12] = 5511.8;    // Octane
  xHN[13] = 6171.15;   // Nonane
  xHN[14] = 6829.77;   // Decane
  xHN[15] = 285.83;    // Hydrogen
  xHN[16] = 0;         // Oxygen
  xHN[17] = 282.98;    // Carbon monoxide
  xHN[18] = 44.016;    // Water
  xHN[19] = 562.01;    // Hydrogen sulfide
  xHN[20] = 0;         // Helium
  xHN[21] = 0;         // Argon
 
  mN2 = MMiGross[2];
  mCO2 = MMiGross[3];
 
}

References b0, b1, b2, bCHx, c0, c1, c2, cCHx, mCO2, MMiGross, mN2, RGross, and xHN.

Referenced by EMSCRIPTEN_BINDINGS().

Variable Documentation

b0

double b0[4][4]

static

Definition at line 130 of file Gross.cpp.

Referenced by Bmix(), and SetupGross().

b1

double b1[4][4]

static

Definition at line 130 of file Gross.cpp.

Referenced by Bmix(), and SetupGross().

b2

double b2[4][4]

static

Definition at line 130 of file Gross.cpp.

Referenced by Bmix(), and SetupGross().

bCHx

double bCHx[3][3]

static

Definition at line 130 of file Gross.cpp.

Referenced by Bmix(), and SetupGross().

c0

double c0[4][4][4]

static

Definition at line 131 of file Gross.cpp.

Referenced by Bmix(), and SetupGross().

c1

double c1[4][4][4]

static

Definition at line 131 of file Gross.cpp.

Referenced by Bmix(), and SetupGross().

c2

double c2[4][4][4]

static

Definition at line 131 of file Gross.cpp.

Referenced by Bmix(), and SetupGross().

cCHx

double cCHx[3][3]

static

Definition at line 130 of file Gross.cpp.

Referenced by Bmix(), and SetupGross().

dPdDsave

double dPdDsave

static

Definition at line 128 of file Gross.cpp.

epsilon

const double epsilon = 1e-15

static

Definition at line 127 of file Gross.cpp.

MaxFlds

const int MaxFlds = 21

static

Definition at line 126 of file Gross.cpp.

mCO2

double mCO2

static

Definition at line 128 of file Gross.cpp.

Referenced by GrossMethod1(), GrossMethod2(), and SetupGross().

MMiGross

double MMiGross[MaxFlds+1]

static

Definition at line 129 of file Gross.cpp.

Referenced by MolarMassGross(), and SetupGross().

mN2

double mN2

static

Definition at line 128 of file Gross.cpp.

Referenced by GrossMethod1(), GrossMethod2(), and SetupGross().

NcGross

const int NcGross = 21

static

Definition at line 126 of file Gross.cpp.

Referenced by GrossHv(), and MolarMassGross().

RGross

double RGross

static

Definition at line 125 of file Gross.cpp.

Referenced by DensityGross(), GrossInputs(), GrossMethod1(), GrossMethod2(), PressureGross(), and SetupGross().

xHN

double xHN[MaxFlds+1]

static

Definition at line 129 of file Gross.cpp.

Referenced by GrossHv(), and SetupGross().