johnpye/fprops/helmholtz.h

/*  ASCEND modelling environment
    Copyright (C) 2008 Carnegie Mellon University

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2, or (at your option)
    any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place - Suite 330,
    Boston, MA 02111-1307, USA.
*/

#ifndef FPROPS_HELMHOLTZ_H
#define FPROPS_HELMHOLTZ_H

#include "ideal.h"

/**
    Data structure for rows of the coefficient and exponent table (allows
    the data to be represented more concisely when declaring a fluid from
    C code.
*/
typedef struct HelmholtzPowTerm_struct{
    double a; /* coefficient */
    double t; /* exponent of tau */
    int d; /* exponent of delta */
    unsigned l; /* exponent X in exp(-del^X) */
} HelmholtzPowTerm;

/*
    Data structure for Gaussian terms in the residual expression, for
    improvement of correlation in the critical region. These terms are of the
    form as utilised in the correlations for water (see water.c) and hydrogen
    (see hydrogen.c). According to Leachman, these terms are due to Setzmann
    and Wagner (J Phys Chem Ref Data, 1966).

    Using the nomenclature of IAPWS-95 (see water.c), terms here for the reduced
    helmholtz energy are:

        n * del^d * tau^t * exp[-alpha*(delta-epsilon)^2 - beta*(tau-gamma)^2]

    NOTE the minus signs preceeding 'alpha' and 'beta' and note that this is
    in conflict with the sign convention of Leachman, who assumes a plus sign
    in front of the corresponding parameters in his equation.

    NOTE these terms are also used in Span et al, 1998, as cited in the file
    'nitrogen.c', but in that case, epsilon == 1 for all terms.
*/
typedef struct HelmholtzGausTerm_struct{
    double n; /**< coefficient */
    double t; /**< power of tau */
    double d; /**< power of delta */
    double alpha,beta,gamma,epsilon;
} HelmholtzGausTerm;

/*
    Data structure for 'critical terms' in the residual expression. These
    terms are of the form described in the IAPWS-95 document, as cited in 
    the file 'water.c'.

    This structure is for the second kind, with A, B, C, D.
*/
typedef struct HelmholtzCritTerm_struct{
    double n; /**< coefficient */
    double a,b,beta,A,B,C,D;
} HelmholtzCritTerm;

/**
    Data structure for fluid-specific data for the Helmholtz free energy EOS.
    See Tillner-Roth 1993 for information about 'atd' and 'a0' data.
*/
typedef struct HelmholtzData_struct{
    double R; /**< specific gas constant */
    double M; /**< molar mass, kg/kmol */
    double rho_star; /**< normalisation density, kg/m�� */
    double T_star; /* normalisation temperature, K */
    
    const IdealData *ideal; /* data for ideal component of Helmholtz energy */

    unsigned np; /* number of power terms in residual equation */
    const HelmholtzPowTerm *pt; /* power term data for residual eqn, maybe NULL if np == 0 */
    unsigned ng; /* number of critical terms of the first kind */
    const HelmholtzGausTerm *gt; /* critical terms of the first kind */
    unsigned nc; /* number of critical terms of the second kind */
    const HelmholtzCritTerm *ct; /* critical terms of the second kind */
} HelmholtzData;

double helmholtz_p(double T, double rho, const HelmholtzData *data);
double helmholtz_u(double T, double rho, const HelmholtzData *data);
double helmholtz_h(double T, double rho, const HelmholtzData *data);
double helmholtz_s(double T, double rho, const HelmholtzData *data);
double helmholtz_a(double T, double rho, const HelmholtzData *data);
double helmholtz_cv(double T, double rho, const HelmholtzData *data);
double helmholtz_cp(double T, double rho, const HelmholtzData *data);
double helmholtz_w(double T, double rho, const HelmholtzData *data);

double helmholtz_cp0(double T, const HelmholtzData *data);

double helmholtz_dpdT_rho(double T, double rho, const HelmholtzData *data);
double helmholtz_dpdrho_T(double T, double rho, const HelmholtzData *data);

double helmholtz_dhdT_rho(double T, double rho, const HelmholtzData *data);
double helmholtz_dhdrho_T(double T, double rho, const HelmholtzData *data);

double helmholtz_dudT_rho(double T, double rho, const HelmholtzData *data);
double helmholtz_dudrho_T(double T, double rho, const HelmholtzData *data);

#endif

1	/* ASCEND modelling environment
2	Copyright (C) 2008 Carnegie Mellon University
3
4	This program is free software; you can redistribute it and/or modify
5	it under the terms of the GNU General Public License as published by
6	the Free Software Foundation; either version 2, or (at your option)
7	any later version.
8
9	This program is distributed in the hope that it will be useful,
10	but WITHOUT ANY WARRANTY; without even the implied warranty of
11	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12	GNU General Public License for more details.
13
14	You should have received a copy of the GNU General Public License
15	along with this program; if not, write to the Free Software
16	Foundation, Inc., 59 Temple Place - Suite 330,
17	Boston, MA 02111-1307, USA.
18	*/
19
20	#ifndef FPROPS_HELMHOLTZ_H
21	#define FPROPS_HELMHOLTZ_H
22
23	#include "ideal.h"
24
25	/**
26	Data structure for rows of the coefficient and exponent table (allows
27	the data to be represented more concisely when declaring a fluid from
28	C code.
29	*/
30	typedef struct HelmholtzPowTerm_struct{
31	double a; /* coefficient */
32	double t; /* exponent of tau */
33	int d; /* exponent of delta */
34	unsigned l; /* exponent X in exp(-del^X) */
35	} HelmholtzPowTerm;
36
37	/*
38	Data structure for Gaussian terms in the residual expression, for
39	improvement of correlation in the critical region. These terms are of the
40	form as utilised in the correlations for water (see water.c) and hydrogen
41	(see hydrogen.c). According to Leachman, these terms are due to Setzmann
42	and Wagner (J Phys Chem Ref Data, 1966).
43
44	Using the nomenclature of IAPWS-95 (see water.c), terms here for the reduced
45	helmholtz energy are:
46
47	n * del^d * tau^t * exp[-alpha(delta-epsilon)^2 - beta(tau-gamma)^2]
48
49	NOTE the minus signs preceeding 'alpha' and 'beta' and note that this is
50	in conflict with the sign convention of Leachman, who assumes a plus sign
51	in front of the corresponding parameters in his equation.
52
53	NOTE these terms are also used in Span et al, 1998, as cited in the file
54	'nitrogen.c', but in that case, epsilon == 1 for all terms.
55	*/
56	typedef struct HelmholtzGausTerm_struct{
57	double n; /*< coefficient /
58	double t; /*< power of tau /
59	double d; /*< power of delta /
60	double alpha,beta,gamma,epsilon;
61	} HelmholtzGausTerm;
62
63	/*
64	Data structure for 'critical terms' in the residual expression. These
65	terms are of the form described in the IAPWS-95 document, as cited in
66	the file 'water.c'.
67
68	This structure is for the second kind, with A, B, C, D.
69	*/
70	typedef struct HelmholtzCritTerm_struct{
71	double n; /*< coefficient /
72	double a,b,beta,A,B,C,D;
73	} HelmholtzCritTerm;
74
75	/**
76	Data structure for fluid-specific data for the Helmholtz free energy EOS.
77	See Tillner-Roth 1993 for information about 'atd' and 'a0' data.
78	*/
79	typedef struct HelmholtzData_struct{
80	double R; /*< specific gas constant /
81	double M; /*< molar mass, kg/kmol /
82	double rho_star; /*< normalisation density, kg/m�� /
83	double T_star; /* normalisation temperature, K */
84
85	const IdealData ideal; / data for ideal component of Helmholtz energy */
86
87	unsigned np; /* number of power terms in residual equation */
88	const HelmholtzPowTerm pt; / power term data for residual eqn, maybe NULL if np == 0 */
89	unsigned ng; /* number of critical terms of the first kind */
90	const HelmholtzGausTerm gt; / critical terms of the first kind */
91	unsigned nc; /* number of critical terms of the second kind */
92	const HelmholtzCritTerm ct; / critical terms of the second kind */
93	} HelmholtzData;
94
95	double helmholtz_p(double T, double rho, const HelmholtzData *data);
96	double helmholtz_u(double T, double rho, const HelmholtzData *data);
97	double helmholtz_h(double T, double rho, const HelmholtzData *data);
98	double helmholtz_s(double T, double rho, const HelmholtzData *data);
99	double helmholtz_a(double T, double rho, const HelmholtzData *data);
100	double helmholtz_cv(double T, double rho, const HelmholtzData *data);
101	double helmholtz_cp(double T, double rho, const HelmholtzData *data);
102	double helmholtz_w(double T, double rho, const HelmholtzData *data);
103
104	double helmholtz_cp0(double T, const HelmholtzData *data);
105
106	double helmholtz_dpdT_rho(double T, double rho, const HelmholtzData *data);
107	double helmholtz_dpdrho_T(double T, double rho, const HelmholtzData *data);
108
109	double helmholtz_dhdT_rho(double T, double rho, const HelmholtzData *data);
110	double helmholtz_dhdrho_T(double T, double rho, const HelmholtzData *data);
111
112	double helmholtz_dudT_rho(double T, double rho, const HelmholtzData *data);
113	double helmholtz_dudrho_T(double T, double rho, const HelmholtzData *data);
114
115	#endif
116