// water

#include "Water.h"
#include <math.h>
#include <string.h>

namespace tpx {

static const double Tmn=273.16;
static const double Tmx=1600.0;
static const double M=18.016;
static const double Tc=647.286;
static const double Pc=22.089e6;
static const double Roc=317.0;
static const double To=273.16;
static const double R=461.51;
static const double E=4.8E-3;
static const double Ta=1000.0;
static const double tauc=1.544912;
static const double Tp=338.15;
static const double aww=0.01;
static const double Roa1=634.0;
static const double Roaj=1000.0;
static const double u0=2375470.875;
static const double s0=6697.356635;

static const double A[10][7]={{2.9492937E-2,-5.1985860E-3,
                               6.8335354E-3,-1.5641040E-4,
	-6.3972405E-3, -3.9661401E-3, -6.9048554E-4},
	{-1.3213917E-4,7.7779182E-6, -2.6149751E-5,-7.2546108E-7,
	 2.6409282E-5, 1.5453061E-5,2.7407416E-6},
	{2.7464632E-7,-3.3301902E-8,6.5326396E-8,-9.2734289E-9,
	 -4.7740374E-8,-2.9142470E-8,-5.1028070E-9},
	{-3.6093828E-10, -1.6254622E-11, -2.6181978E-11, 4.3125840E-12,
	 5.6323130E-11, 2.9568796E-11,3.9636085E-12},
	{3.4218431E-13, -1.7731074E-13,0,0,0,0,0},
	{-2.4450042E-16, 1.2748742E-16,0,0,0,0,0},
	{1.5518535E-19, 1.3746153E-19,0,0,0,0,0},
	{5.9728487E-24,1.5597836E-22, 0,0,0,0,0},
	{-4.1030848E-1, 3.3731180E-1, -1.3746678E-1, 6.7874983E-3,
	 1.3687317E-1, 7.984797E-2, 1.3041253E-2},
	{-4.1605860E-4, -2.0988866E-4,-7.3396848E-4,1.0401717E-5,
	 6.4581880E-4, 3.9917570E-4, 7.1531353E-5}};

static const double F[]={-7.4192420, 2.9721E-1,-1.155286E-1,8.685635E-3,
	1.0940980E-3, -4.39993E-3, 2.5206580E-3, -5.2186840E-4};

static const double D[]={3.6711257,-2.8512396E1,2.2265240E2,-8.8243852E2,
	2.0002765E3,-2.6122557E3,1.8297674E3,-5.3350520E2};

static const double G[]={4.6E4,1.011249E3,8.3893E-1,-2.19989E-4,2.466619E-7,
	-9.704700E-11};

static const double taua[] = {1.544912, 2.5, 2.5, 2.5, 2.5, 2.5, 2.5};

inline double water::C(int i) {
   double tau = Ta/T;
   return (i == 0 ? R*T : R*T*(tau - tauc)*pow(tau - taua[i],i-1));
   }

inline double water::Cprime(int i) {
   double tau = Ta/T;
   return (i == 0 ? R : (i == 1 ? -R*tauc : 
             -R*pow(tau - taua[i],i-2)*(tauc*(tau - taua[i]) 
				     + (i-1)*tau*(tau - tauc))));
   }

inline double water::I(int j) {
   double factor, sum, rho_aj;
   rho_aj = (j == 0 ? Roa1 : Roaj);
   sum = 0.0;
   factor = Rho - rho_aj;
   for(int i=7; i>0; i--) {
      sum += A[i][j];
      sum *= factor;
      }
   sum += A[0][j];
   sum += (exp(-E*Rho)*(A[8][j] + A[9][j]*Rho));
   return Rho*sum;
   }

inline double water::H(int j) {
   double factor, sum, rho_aj;
   rho_aj = (j == 0 ? Roa1 : Roaj);
   sum = 0.0;
   factor = Rho - rho_aj;
   for(int i=6; i>0; i--) {
      sum += (A[i][j] + Rho*(i+1)*A[i+1][j]);
      sum *= factor;
      }
   sum += (A[0][j] + Rho*A[1][j]);
   sum += (exp(-E*Rho)*((1.0 - Rho*E)*A[8][j] 
          + Rho*(2.0 - Rho*E)*A[9][j]));
   sum += A[7][j]*pow(factor,7);
   return Rho*Rho*sum;
   }

double water::up() {
   double sum = 0.0;
   int i;
   for (i=0; i<7; i++)
      sum += (C(i) - T*Cprime(i))*I(i);
   for (i=1; i<6; i++)
      sum += G[i]*(pow(T,i) - pow(To,i))/double(i);
   sum += G[0]*log(T/To) + u0;
   return sum + m_energy_offset;
   }

double water::sp() {
   double sum = 0.0;
   int i;
   for (i=2; i<6; i++)
      sum += G[i]*(pow(T,i-1) - pow(To,i-1))/double(i-1);
   sum += G[1]*log(T/To);
   sum -= G[0]*(1.0/T - 1.0/To);
   sum += s0 - R*log(Rho);
   for (i=0; i<7; i++)
      sum -= Cprime(i)*I(i);
   return sum + m_entropy_offset;
   }
 
double water::Pp(){
   double P = Rho*R*T;
   for(int i=0; i<7; i++)
      P += C(i)*H(i);
   return P;
   }

double water::Psat(){
	double log, sum=0,P;
	if ((T < Tmn) || (T > Tc))
	   set_Err(TempError); // Error("water::Psat",TempError,T);
	for (int i=1;i<=8;i++)
		sum += F[i-1]*pow(aww*(T-Tp),double(i-1)); // DGG mod
	log = (Tc/T-1)*sum;
	P=exp(log)*Pc;
	return P;
}

/*
double water::dPsatdT(){
	double log, sum1=0, sum2=0;
        int i;
	if ((T < Tmn) || (T > Tc))
	   set_Err(TempError); // Error("water::dPsatdT",TempError,T);
	for (i=1;i<=8;i++)
		sum1 += F[i-1]*pow(a*(T-Tp),double(i-1));
	for (i=2;i<=8;i++)
		sum2 += F[i-1]*a*(i-1)*pow(a*(T-Tp),double(i-2));
	log = (Tc/T-1)*sum2 - Tc*sum1/(T*T);
	return log*Psat();
}
*/

double water::ldens(){
	double sum=0;
	int i;
	if ((T < Tmn) || (T >= Tc)) 
	   set_Err(TempError); // Error("water::ldens",TempError,T);
	for(i=0;i<=8;i++)
		sum+=D[i-1]*pow(1.0 - T/Tc, double(i)/3.0);
	double density = Roc*(1+sum);
	return density;
}

double water::Tcrit() {return Tc;}
double water::Pcrit() {return Pc;}
double water::Vcrit() {return 1.0/Roc;}
double water::Tmin() {return Tmn;}
double water::Tmax() {return Tmx;}
char * water::name() {
  return (char *) m_name.c_str();
}
char * water::formula() {
  return (char *) m_formula.c_str();
}
double water::MolWt() {return M;}

}