/* Submodel PNL0002 skeleton created by AME Submodel editing utility
   mer. juin 20 14:35:13 2018 */



#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include "ameutils.h"
/* *******************************************************************************
TITLE : PNL0002 (R-C-R)
------------------------------------------------------------------------------
DESCRIPTION :
   PNL0002 is a submodel of a pneumatic pipe with only compressibility
   and friction effects taking into account heat exchange. 
 
   The compressibility of the gas is taken into account by using a
   simple polytropic model or a more complex one taking into account
   heat exchange. 
 
   The polytropic model is a simplified form of the general internal
   energy model based on the first law of thermodynamics. The polytropic
   approach is obtained by representing the thermal exchange phenomena
   by a polytropic constant k. In that case, the temperature and
   pressure are no more independent variables.
 
   The reduction of the complexity of the model implies a lack of
   accuracy. For general studies, you'd better use the heat exchange
   approach.
 
   Pipe friction is taken into account using a friction factor based on
   the Reynolds number and the relative roughness.
 
   The temperature and pressure in the middle volume are state variables. 
------------------------------------------------------------------------------
USAGE :
   Use this submodel to simulate a pneumatic pipe with compressibility
   and friction effects, when the Mach number is low, ie gas velocity
   < 0.3 * speed of sound .
  
   PNL0002 is basically similar to PNL0001 and PNL0003 differing only in the
   input and output requirements.
 
   The submodels PNGD01 or PNGD02 should be included in your circuit to
   define the characteristics of the gas.
------------------------------------------------------------------------------
PARAMETER SETTINGS : 
------------------------------------------------------------------------------
DATE OF CREATION / AUTHOR : 
  2002 FS from PNL02 SN.
------------------------------------------------------------------------------
REVISIONS :
------------------------------------------------------------------------------
LIST OF FUNCTIONS USED :
   pn2getatp_()   : get atmospheric pressure
   pn2ri_()       : get perfect gas constant
   pn2vol1_()     : polytropic model for chambers  
   pn2vol_()      : heat exchange model for chambers
   pn2pipefr_()   : frictional coeffitient in pneumatic pipes
------------------------------------------------------------------------------
SOURCE :

   This material contains trade secrets or otherwise confidential
   information owned by Siemens Industry Software Inc. or its
   affiliates (collectively, "Siemens"), or its licensors. Access to
   and use of this information is strictly limited as set forth in the
   Customer's applicable agreements with Siemens.
   
   Unpublished work. Copyright 2023 Siemens

******************************************************************************* */

#define _SUBMODELNAME_ "PNL0002"

/* >>>>>>>>>>>>Insert Private Code Here. */
#define TABFR      0 /* real store 0, 1 & 2 are used by pn2pipefr */
#define PATM       3
#define AREA       4
#define VOL        5
#define HALFLE     6
#define AREAEX     7


#define SPL_FR   0
/* <<<<<<<<<<<<End of Private Code. */


/* There are 6 real parameters:

   diam   diameter of pipe             [mm -> m]
   le     pipe length                  [m]
   rr     relative roughness           [null]
   k      polytropic constant          [null]
   kth    thermal exchange coefficient [J/m**2/K/s -> W/m**2/K]
   extemp external temperature         [K]
*/


/* There are 2 integer parameters:

   gi   gas type index
   mode model         
*/

void pnl0002in_(int *n, double rp[6], int ip[2], double c[8]
      , int ic[1], double *tctr, double *pctr)

{
   int loop, error;
/* >>>>>>>>>>>>Extra Initialization Function Declarations Here. */
/* <<<<<<<<<<<<End of Extra Initialization declarations. */
   int gi, mode;
   double diam, le, rr, k, kth, extemp;

   gi         = ip[0];
   mode       = ip[1];

   diam       = rp[0];
   le         = rp[1];
   rr         = rp[2];
   k          = rp[3];
   kth        = rp[4];
   extemp     = rp[5];
   loop = 0;
   error = 0;

/*
   If necessary, check values of the following:

   rp[0..5]
   *tctr
   *pctr
*/


/* >>>>>>>>>>>>Initialization Function Check Statements. */

   pn2_valid_gas_(&gi, &error);

   if (*pctr < -GPATMOS)
   {
      error = 2;
      amefprintf(stderr, "\nInitial pressure at center of pipe should be > 0 [barA].\n");
   }

   if (*tctr <= 0.0)
   {
      error = 2;
      amefprintf(stderr, "\nInitial temperature at center of pipe should be > 0 [K].\n");
   }

   if (diam <= 0.0)
   {
      error = 2;
      amefprintf(stderr, "\nDiameter of pipe should be > 0 [mm].\n");
   }

   if (le <= 0.0)
   {
      error = 2;
      amefprintf(stderr, "\nPipe length should be > 0 [m].\n");
   }

   if (rr < 0.0)
   {
      error = 2;
      amefprintf(stderr, "\nRelative roughness should be >= 0.\n");
   }

   if (mode == 1)
   {
      if (k <= 0.)
      {
         error = 2;
         amefprintf(stderr, "\nPolytropic constant should be > 0.\n");
      }
   }
   else
   {
      if (kth < 0.)
      {
         error = 2;
         amefprintf(stderr, "\nThermal exchange coefficient should be >= 0 [J/m**2/K/s].\n");
      }

      if (extemp <= 0.)
      {
         error = 2;
         amefprintf(stderr, "\nExternal temperature should be > 0 [K].\n");
      }
   }

/* <<<<<<<<<<<<End of Initialization Check Statements. */

/*   Integer parameter checking:   */

   if (gi < 1 || gi > 99)
   {
      amefprintf(stderr, "\ngas type index must be in range [1..99].\n");
      error = 2;
   }
   if (mode < 1 || mode > 2)
   {
      amefprintf(stderr, "\nmodel must be in range [1..2].\n");
      error = 2;
   }

   SUBMODEL_HANDLE_AND_RESET_ERROR(_SUBMODELNAME_, n, error)

/* Common -> SI units conversions. */

   rp[0]    *= 1.00000000000000e-003;
   diam       = rp[0];


/* >>>>>>>>>>>>Initialization Function Executable Statements. */

   /* get atmospheric pressure */
   c[PATM] = pn2getatp_();

   /* Compute the cross-sectional area of pipe. */
   c[AREA] = M_PI * (diam) * (diam) / 4.0;

   /* Compute volume of pipe. */
   c[VOL] = c[AREA] * le;

   /* Divide the restriction in 2 identical restrictions */
   c[HALFLE] = 0.5 * le;

   /* Compute exchange area of pipe. */
   c[AREAEX] = M_PI * diam * le;

/* <<<<<<<<<<<<End of Initialization Executable Statements. */
}

/*  There are 2 ports.

   Port 1 has 4 variables:

      1 dh1     enthalpy flow rate at port 1 [J/s -> W]    basic variable output
      2 dm1     mass flow rate at port 1     [g/s -> kg/s] basic variable output
      3 t1      temperature at port 1        [K]           basic variable input
      4 p1      pressure at port 1           [Pa]          basic variable input

   Port 2 has 4 variables:

      1 dh2     enthalpy flow rate at port 2 [J/s -> W]    basic variable output
      2 dm2     mass flow rate at port 2     [g/s -> kg/s] basic variable output
      3 t2      temperature at port 2        [K]           basic variable input
      4 p2      pressure at port 2           [Pa]          basic variable input
*/

/*  There are 7 internal variables.

      1 tctr     temperature at center of pipe [K]               explicit state (derivative `dtctr')
      2 pctr     pressure at center of pipe    [Pa]              explicit state (derivative `dpctr')
      3 mgas     mass of gas in pipe           [g -> kg]         basic variable
      4 re       mean Reynolds number          [null]            basic variable
      5 cm       mean mass flow parameter      [(kg*K/J)**(1/2)] basic variable
      6 v        mean gas velocity             [m/s]             basic variable
      7 ff       mean friction factor          [null]            basic variable
*/

void pnl0002_(int *n, double *dh1, double *dm1, double *t1, double *p1
      , double *dh2, double *dm2, double *t2, double *p2, double *tctr
      , double *dtctr, double *pctr, double *dpctr, double *mgas
      , double *re, double *cm, double *v, double *ff, double rp[6]
      , int ip[2], double c[8], int ic[1])

{
   int loop;
/* >>>>>>>>>>>>Extra Calculation Function Declarations Here. */
   static double zero = 0.0;
   double sdh;
   double dh1i, dm1i;
   double dh2i, dm2i;
   double ff1, ff2, re1, re2, cm1, cm2;
   double dq;
   double pa1, pa2, pactr;
   double v1, v2;
   double dmgas;
   double r;
   int dummyreg;
/* <<<<<<<<<<<<End of Extra Calculation declarations. */
   int gi, mode;
   double diam, le, rr, k, kth, extemp;

   gi         = ip[0];
   mode       = ip[1];

   diam       = rp[0];
   le         = rp[1];
   rr         = rp[2];
   k          = rp[3];
   kth        = rp[4];
   extemp     = rp[5];
   loop = 0;

/*
   Set all submodel outputs below:

   *dh1        = ??;
   *dm1        = ??;
   *dh2        = ??;
   *dm2        = ??;
   *dtctr      = ??;
   *dpctr      = ??;
   *mgas       = ??;
   *re         = ??;
   *cm         = ??;
   *v          = ??;
   *ff         = ??;
*/



/* >>>>>>>>>>>>Calculation Function Executable Statements. */

   /* set absolute pressure */
   pa1   =   *p1 + c[PATM];
   pa2   =   *p2 + c[PATM];
   pactr = *pctr + c[PATM];

   /* Compute flows through the pipe */
   pn2pipefr_(&pa1, t1, &pactr, tctr, &diam, &rr, &c[HALFLE], &c[AREA], &re1, &v1, &ff1,
              dh1, dm1, &dh1i, &dm1i, &cm1, &c[TABFR], &gi, &ic[SPL_FR], &dummyreg);

   pn2pipefr_(&pactr, tctr, &pa2, t2, &diam, &rr, &c[HALFLE], &c[AREA], &re2, &v2, &ff2,
              &dh2i, &dm2i, dh2, dm2, &cm2, &c[TABFR], &gi, &ic[SPL_FR], &dummyreg);

   /* Mean variables */
   *ff = 0.5 * (ff1 + ff2);
   *re = 0.5 * (re1 + re2);
   *cm = 0.5 * (cm1 + cm2);
   *v  = 0.5 * (fabs(v1) + fabs(v2));

   /* Compute mass variation */
   dmgas = dm1i + dm2i;

   /* sum of enthalpy flows */
   sdh = dh1i + dh2i;

   /*** temperature & pressure variation ***/
   if (mode == 1) /* Polytropic model. */
   {
      r = pn2ri_(&gi);
      *mgas = (pactr) * c[VOL] / ((*tctr) * r);

      pn2vol1_(dtctr, dpctr, tctr, &pactr,
               &dmgas, mgas, &zero, &c[VOL], &k, &gi);
   }
   else /* Heat exchange. */
   {
      dq = kth * c[AREAEX] * (extemp-*tctr);

      pn2vol_(dtctr, dpctr, mgas, tctr, &pactr,
              &dmgas, &sdh, &c[VOL], &zero, &dq, &gi);
   }

/* <<<<<<<<<<<<End of Calculation Executable Statements. */

/* SI -> Common units conversions. */

   *dm1      /= 1.00000000000000e-003;
   *dm2      /= 1.00000000000000e-003;
   *mgas     /= 1.00000000000000e-003;
}