/****************************************************************
 * FUNCTION hotsim.c - evaluates the heater performance         *
 * FILENAME:       hotsim.c                                     *
 * PROGRAMMERS:    Izzi Urieli (FORTRAN)                        *
 *                 Eric Malroy (translation to "C")             *
 * DATE:           120194/080996                                *
 * LAST MODIFICATION: 08/23/96 Eric Malroy                      *
 * INCLUDE:        <stdio.h>,<math.h>,"define.h","adiabatic.h"  *
 *                 "simple.h"                                   *
 * GLOBAL VARIABLES:                                            *
 *       omega - frequency (rad/sec)                            *
 *       ah    - heater internal free flow area                 *
 *       th    - hot sink operation temperature (K)             *
 *       dh    - heater hydraulic diameter (m)                  *
 * PROTOTYPE:                                                   *
 *       void hotsim(double [][], double, double *)             *
 * PRE:  omega, ah, th, dh                                      *
 * POST: *tgh                                                   *
 ****************************************************************/
#include <stdio.h>
#include <math.h>
#include "define.h"
#include "adiabatic.h"
#include "simple.h"

void hotsim(double var[][COL], /* variable matrix          */
            double twh,        /* heater wall temp (K)     */
            double *pt_tgh)    /* heater average gas temp. */
{
/**** variables ****/

double gah[COL];  /* mass flow through heater (kg/s) */
double gh;        /* mass flux through heater (kg/(m**2*s)  */
double re[COL];   /* Reynolds number                        */
double sum_re;
double re_avg;    /* average Reynolds number over the cycle */
double re_max;    /* max Reynolds number over the cycle     */
double ht;        /* heat transfer coefficient (W/(m**2*K)) */
double fr;        /* Reynolds friction factor               */
double mu;        /* dynamic viscosity (kg/(m*s))           */
double kgas;      /* gas thermal conductivity (W/(m**2*K))  */
double tgh;       /* heater average gas temperature         */
int i;            /* index for "for" loop                   */

/**** Reynolds number over the cycle ****/
   for(i=0;i<37;i++) {
      gah[i] = (var[GARH][i] + var[GAHE][i])*omega/2.0;
      gh = gah[i]/ah;
      reynum(th,gh,dh,&mu,&kgas,&re[i]);
   }

/**** average and maximum Reynolds number ****/
   sum_re = 0;
   re_max = re[0];
   for(i=0;i<36;i++) {
      sum_re = sum_re + re[i];
      if(re[i] > re_max)
         re_max = re[i];
   }
   re_avg = sum_re/36.0;

/**** heat transfer coefficient (W/(m**2*K)) & heater gas temp tgh(K) ****/
   pipfr(dh,mu,re_avg,&ht,&fr);
   tgh = twh - var[QH][36]*freq/(ht*awgh);
   *pt_tgh = tgh;

   printf("\n heater Simple analysis:");
   printf("\n average Reynolds number, %.3f", re_avg);
   printf("\n maximum Reynolds number, %.3f", re_max);
   printf("\n heat transfer coefficient (W/(m^2*k)), %.3f", ht);
   printf("\n Wall temp (K), %.2f", twh);
   printf("Gas temp (K), %.2f\n", tgh);

   fprintf(printfile,"\n heater Simple analysis:");
   fprintf(printfile,"\n average Reynolds number, %.3f", re_avg);
   fprintf(printfile,"\n maximum Reynolds number, %.3f", re_max);
   fprintf(printfile,"\n heat transfer coefficient (W/(m^2*k)), %.3f", ht);
   fprintf(printfile,"\nWall temp (K), %.2f", twh);
   fprintf(printfile,"Gas temp (K), %.2f\n", tgh);
}