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#include "ammonia.h" |
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|
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/* Property data for Nitrogen |
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|
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From Span, Lemmon, Jacobsen & Wagner |
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A Reference Quality Equation of State for Nitrogen |
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Int J Thermophysics, Vol 18, No 4, 1998. |
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|
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This is the nitrogren property correlation recommended |
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by NIST in its program REFPROP 7.0. */ |
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|
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const IdealData ideal_data_nitrogen = { |
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-12.76953 /* constant */ |
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,-0.007841630 /* linear */ |
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, 3 /* power terms */ |
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, (const IdealPowTerm[]){ |
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{1.934819, -1.} |
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,{-1.247742e-5, -2.} |
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,{6.678326e-8, -3.} |
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} |
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, 1 |
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, (const IdealExpTerm[]){ |
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{1.012941, 26.65788} |
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} |
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}; |
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|
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/* |
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this correlation is given in molar terms. we convert to mass |
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basis by changing the scaling density rho_star, and the ideal gas constant. |
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*/ |
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#define M_NITROGEN 28.01348 |
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const HelmholtzData helmholtz_data_nitrogen = { |
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/* R */ 1e3 * 8.31451 / M_NITROGEN /* 1000 * kJ/kmolK / kg/kmol = J/kgK */ |
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, /* M */ M_NITROGEN /* kg/kmol */ |
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, /* rho_star */ 11.1839 * M_NITROGEN /* kmol/m3 * kg/kmol = kg/m続 (= rho_c for this model) */ |
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, /* T_star */ 126.192 /* K (= T_c for this model) */ |
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, &ideal_data_nitrogen |
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, 32 /* np */ |
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, (const HelmholtzPowTerm[]){ |
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/* a_i, t_i, d_i, l_i */ |
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{ 0.924803575275, 0.25, 1, 0}/* 1 */ |
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,{-0.492448489428, 0.875, 1, 0} |
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,{ 0.661883336938, 0.5, 2, 0} |
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,{-0.192902649201E1, 0.875, 2, 0} |
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,{-0.622469309629E-1, 0.375, 3, 0} |
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,{ 0.349943957581, 0.75, 3, 0} |
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,{ 0.564857472498, 0.5, 1, 1} |
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,{-0.161720005987E1, 0.75, 1, 1} |
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,{-0.481395031883, 2., 1, 1} |
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,{ 0.421150636384, 1.25, 3, 1}/* 10 */ |
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,{-0.161962230825E-1, 3.5, 3, 1} |
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,{ 0.172100994165, 1., 4, 1} |
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,{ 0.735448924933E-2, 0.5, 6, 1} |
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,{ 0.168077305479E-1, 3., 6, 1} |
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,{-0.107626664179E-2, 0., 7, 1} |
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,{-0.137318088513E-1, 2.75, 7, 1} |
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,{ 0.635466899859E-3, 0.75, 8, 1} |
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,{ 0.304432279419E-2, 2.5, 8, 1} |
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,{-0.435762336045E-1, 4., 1, 2} |
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,{-0.723174889316E-1, 6. , 2, 2}/* 20 */ |
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,{ 0.389644315272E-1, 6., 3, 2} |
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,{-0.212201363910E-1, 3., 4, 2} |
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,{ 0.408822981509E-2, 3., 5, 2} |
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,{-0.551990017984E-4, 6., 8, 2} |
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,{-0.462016716479E-1, 16., 4, 3} |
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,{-0.300311716011E-2, 11., 5, 3} |
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,{ 0.368825891208E-1, 15., 5, 3} |
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,{-0.255856846220E-2, 12., 8, 3} |
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,{ 0.896915264558E-2, 12., 3, 4} |
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,{-0.441513370350E-2, 7., 5, 4} |
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,{ 0.133722924858E-2, 4., 6, 4} |
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,{ 0.264832491957E-3, 16., 9, 4} |
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} |
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, 4 /* ne */ |
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, (const HelmholtzExpTerm[]){ |
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{0.196688194015e2, 0., 1, 20, 325, 1.16} |
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, {-0.209115600730e2, 1., 1, 20, 325, 1.16} |
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, {0.167788306989e-1, 2., 3, 15, 300, 1.13} |
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, {0.262767566274e4, 3., 2, 25, 275, 1.25} |
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} |
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}; |
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|
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|
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/* |
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Test suite. These tests attempt to validate the current code using |
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a few sample figures output by REFPROP 7.0. |
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|
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To run the test, compile and run as follows: |
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|
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gcc helmholtz.c nitrogen.c -DTEST -o nitrogen -lm && ./nitrogen |
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|
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These tests all currently pass with a maximum error of 2%. The error |
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seems to arise in the enthalpy data for low temperatures. Haven't been |
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able to determine where the problem comes from. |
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*/ |
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#ifdef TEST |
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|
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#include <assert.h> |
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#include <stdlib.h> |
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#include <stdio.h> |
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#include <math.h> |
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|
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/* a simple macro to actually do the testing */ |
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#define ASSERT_TOL(FN,PARAM1,PARAM2,PARAM3,VAL,TOL) {\ |
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double cval; cval = FN(PARAM1,PARAM2,PARAM3);\ |
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double err; err = cval - (double)(VAL);\ |
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double relerrpc = (cval-(VAL))/(VAL)*100;\ |
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if(fabs(relerrpc)>maxerr)maxerr=fabs(relerrpc);\ |
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if(fabs(err)>TOL){\ |
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fprintf(stderr,"ERROR in line %d: value of '%s(%f,%f,%s)' = %f,"\ |
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" should be %f, error is %f (%.2f%%)!\n"\ |
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, __LINE__, #FN,PARAM1,PARAM2,#PARAM3, cval, VAL,cval-(VAL)\ |
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,relerrpc\ |
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);\ |
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exit(1);\ |
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}else{\ |
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fprintf(stderr," OK, %s(%f,%f,%s) = %8.2e with %.2f%% err.\n"\ |
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,#FN,PARAM1,PARAM2,#PARAM3,VAL,relerrpc\ |
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);\ |
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}\ |
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} |
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|
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typedef struct{double T,p,rho,h,s;} TestData; |
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const TestData td[]; const unsigned ntd; |
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|
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int main(void){ |
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|
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double rho, T, p, h, u; |
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const HelmholtzData *d; |
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|
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d = &helmholtz_data_nitrogen; |
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double maxerr = 0; |
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|
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unsigned i; |
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const unsigned n = ntd; |
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|
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#if 0 |
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fprintf(stderr,"Testing sample values from the Span paper...\n"); |
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|
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rho = 10.993 * d->M; T = 270.; |
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p = helmholtz_p(T, rho, d); |
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fprintf(stderr,"p = %f\n", p); |
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assert(fabs(p - 27.0621e6) < 5e3); |
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fprintf(stderr,"OK 1\n"); |
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|
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rho = 11.2 * d->M; T = 126.2; |
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p = helmholtz_p(T, rho, d); |
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fprintf(stderr,"p = %f\n", p); |
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assert(fabs(p - 3.39712e6) < 50e3); |
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fprintf(stderr,"OK 2\n"); |
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#endif |
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|
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fprintf(stderr,"Running through %d test points...\n",n); |
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|
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fprintf(stderr,"PRESSURE TESTS\n"); |
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for(i=0; i<n;++i){ |
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T = td[i].T+273.15; |
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p = td[i].p*1e6; |
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rho = td[i].rho; |
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ASSERT_TOL(helmholtz_p, T, rho, d, p, p*1e-6); |
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} |
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|
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/* offset required to attain agreement with REFPROP */ |
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double Y = -471.596704; |
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|
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fprintf(stderr,"ENTROPY TESTS\n"); |
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for(i=0; i<n;++i){ |
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ASSERT_TOL(helmholtz_s, td[i].T+273.15, td[i].rho, d, td[i].s*1e3 + Y, 1E3); |
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} |
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|
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/* this offset is required to attain agreement with values from REFPROP */ |
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double Z = -1635.7e3 + 1492.411e3; |
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|
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fprintf(stderr,"ENTHALPY TESTS\n"); |
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for(i=0; i<n;++i){ |
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ASSERT_TOL(helmholtz_h, td[i].T+273.15, td[i].rho, d, td[i].h*1e3 + Z, 1E3); |
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} |
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|
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fprintf(stderr,"Tests completed OK (maximum error = %0.2f%%)\n",maxerr); |
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exit(0); |
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} |
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|
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const TestData td[] = { |
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/* |
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samples point from Span et al, as calculated by REFPROP 7.0 |
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*/ |
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#if 1 |
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{-3.15E+0, 2.706209546E+1, 3.0814828E+2, 1.448502895E+2, 2.326719559E+2} |
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, {-1.4695E+2, 3.397116495E+0, 3.13750976E+2, 1.832925675E+1, 2.9156686E+1} |
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, |
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#endif |
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/* |
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A small set of data points calculated using REFPROP 7.0, for validation |
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*/ |
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{-2.00E+2, 1.E-1, 8.249414592E+2, -1.305645426E+2, 2.720604877E+0} |
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, {-1.959064992E+2, 1.E-1, 8.065903588E+2, -1.22246837E+2, 2.83124055E+0} |
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, {-1.959064992E+2, 1.E-1, 4.556481103E+0, 7.7072848E+1, 5.41164774E+0} |
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, {-1.50E+2, 1.E-1, 2.765107908E+0, 1.264963652E+2, 5.914940099E+0} |
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, {-1.00E+2, 1.E-1, 1.952885853E+0, 1.789628879E+2, 6.272601137E+0} |
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, {-5.0E+1, 1.E-1, 1.511923126E+0, 2.31146308E+2, 6.537380868E+0} |
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, {0.E+0, 1.E-1, 1.234027837E+0, 2.832365424E+2, 6.74801325E+0} |
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, {5.0E+1, 1.E-1, 1.042637745E+0, 3.353055943E+2, 6.923064311E+0} |
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, {1.00E+2, 1.E-1, 9.027313243E-1, 3.874200009E+2, 7.073009026E+0} |
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, {1.50E+2, 1.E-1, 7.959713424E-1, 4.396650845E+2, 7.204396773E+0} |
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, {2.00E+2, 1.E-1, 7.118143393E-1, 4.921414969E+2, 7.321608221E+0} |
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, {2.50E+2, 1.E-1, 6.437636895E-1, 5.44952141E+2, 7.427704455E+0} |
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, {3.00E+2, 1.E-1, 5.875965268E-1, 5.98189656E+2, 7.524887552E+0} |
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, {3.50E+2, 1.E-1, 5.404484175E-1, 6.519286035E+2, 7.614775644E+0} |
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, {4.00E+2, 1.E-1, 5.003075032E-1, 7.062225739E+2, 7.698579114E+0} |
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, {-2.00E+2, 1.E+0, 8.269722658E+2, -1.298970049E+2, 2.714834497E+0} |
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, {-1.694030878E+2, 1.E+0, 6.658282477E+2, -6.432677729E+1, 3.460052635E+0} |
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, {-1.694030878E+2, 1.E+0, 4.133110398E+1, 8.773400698E+1, 4.92574237E+0} |
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, {-1.50E+2, 1.E+0, 3.089966568E+1, 1.149820382E+2, 5.167381911E+0} |
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, {-1.00E+2, 1.E+0, 2.018992668E+1, 1.731651404E+2, 5.565357304E+0} |
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, {-5.0E+1, 1.E+0, 1.530392626E+1, 2.275480773E+2, 5.841465649E+0} |
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, {0.E+0, 1.E+0, 1.238752228E+1, 2.808281272E+2, 6.056951203E+0} |
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, {5.0E+1, 1.E+0, 1.042615666E+1, 3.336448972E+2, 6.23453053E+0} |
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, {1.00E+2, 1.E+0, 9.009743348E+0, 3.862721678E+2, 6.385956969E+0} |
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, {1.50E+2, 1.E+0, 7.936266563E+0, 4.38890073E+2, 6.518285235E+0} |
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, {2.00E+2, 1.E+0, 7.093503539E+0, 4.916490203E+2, 6.636129311E+0} |
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, {2.50E+2, 1.E+0, 6.413750916E+0, 5.44680595E+2, 6.742670284E+0} |
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, {3.00E+2, 1.E+0, 5.853600946E+0, 5.980951517E+2, 6.840177103E+0} |
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, {3.50E+2, 1.E+0, 5.383882193E+0, 6.519787885E+2, 6.930307557E+0} |
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, {4.00E+2, 1.E+0, 4.984238815E+0, 7.063929319E+2, 7.014296741E+0} |
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, {-2.00E+2, 1.E+1, 8.452673172E+2, -1.229850766E+2, 2.662217387E+0} |
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, {-1.50E+2, 1.E+1, 6.146317008E+2, -2.075504269E+1, 3.721059545E+0} |
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, {-1.00E+2, 1.0E+1, 2.740868419E+2, 1.083371836E+2, 4.599930836E+0} |
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, {-5.0E+1, 1.0E+1, 1.656973184E+2, 1.934337283E+2, 5.035617646E+0} |
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, {0.E+0, 1.0E+1, 1.252477529E+2, 2.592718885E+2, 5.302448665E+0} |
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, {5.0E+1, 1.E+1, 1.024973378E+2, 3.19262156E+2, 5.504302349E+0} |
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, {1.00E+2, 1.E+1, 8.742785901E+1, 3.766273279E+2, 5.66942089E+0} |
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, {1.50E+2, 1.0E+1, 7.653447744E+1, 4.326358439E+2, 5.8103035E+0} |
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, {2.00E+2, 1.0E+1, 6.821629197E+1, 4.879492416E+2, 5.933867436E+0} |
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, {2.50E+2, 1.0E+1, 6.16196599E+1, 5.429759984E+2, 6.044424746E+0} |
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, {3.00E+2, 1.0E+1, 5.624066686E+1, 5.979913509E+2, 6.144858594E+0} |
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, {3.50E+2, 1.0E+1, 5.175958526E+1, 6.531864458E+2, 6.237185757E+0} |
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, {4.00E+2, 1.0E+1, 4.796230162E+1, 7.086931308E+2, 6.32286331E+0} |
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, {-1.50E+2, 1.00E+2, 8.420363237E+2, 3.92374019E+1, 3.242503691E+0} |
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, {-1.00E+2, 1.00E+2, 7.480840694E+2, 1.189018852E+2, 3.7864991E+0} |
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, {-5.0E+1, 1.00E+2, 6.686218021E+2, 1.936838079E+2, 4.166379675E+0} |
| 241 |
, {0.E+0, 1.00E+2, 6.020019153E+2, 2.646716357E+2, 4.453651157E+0} |
| 242 |
, {5.0E+1, 1.00E+2, 5.463770513E+2, 3.326365504E+2, 4.682270323E+0} |
| 243 |
, {1.00E+2, 1.00E+2, 4.998628485E+2, 3.981897474E+2, 4.870958715E+0} |
| 244 |
, {1.50E+2, 1.00E+2, 4.607196175E+2, 4.618644601E+2, 5.031138876E+0} |
| 245 |
, {2.00E+2, 1.00E+2, 4.274764375E+2, 5.241299871E+2, 5.170247187E+0} |
| 246 |
, {2.50E+2, 1.00E+2, 3.989550654E+2, 5.853873016E+2, 5.293334174E+0} |
| 247 |
, {3.00E+2, 1.00E+2, 3.742353905E+2, 6.459672171E+2, 5.40393536E+0} |
| 248 |
, {3.50E+2, 1.00E+2, 3.526046985E+2, 7.061338065E+2, 5.504585302E+0} |
| 249 |
, {4.00E+2, 1.00E+2, 3.335102049E+2, 7.660915686E+2, 5.597138445E+0} |
| 250 |
}; |
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|
| 252 |
const unsigned ntd = sizeof(td)/sizeof(TestData); |
| 253 |
|
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#endif |
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|
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