Changes between Initial Version and Version 1 of cypress/Programming/HeatMassTransfer/ex5.c


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Timestamp:
May 14, 2015 3:15:25 PM (7 years ago)
Author:
cmaggio
Comment:

migrated content from ccs wiki

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  • cypress/Programming/HeatMassTransfer/ex5.c

    v1 v1  
     1= Ex5.c =
     2{{{#!C
     3/*
     4  Large Scale Computing
     5  Heat/Mass Transfer
     6  ex5.c : SOR
     7 */
     8#include<stdio.h>
     9#include<stdlib.h>
     10#include<math.h>
     11 
     12int main(int argc, char **argv){
     13  double a,b,d;
     14  double *phi;
     15  double w;
     16  double *rhs;
     17  double dx;
     18  double err,merr;
     19  double tol = 1.0e-5;
     20  double rlx = 1.8;
     21  int i,num,itc;
     22  FILE *fp;
     23 
     24  if (argc < 5){
     25    printf("Usage:%s [NUM] [A] [B] [D]\n",argv[0]);
     26    exit(-1);
     27  }
     28 
     29  /* set parameters */
     30  num = atoi(argv[1]);
     31  a = atof(argv[2]);
     32  b = atof(argv[3]);
     33  d = atof(argv[4]);
     34 
     35  printf("num=%d A=%e B=%e D=%e\n",num,a,b,d);
     36 
     37  /* Memory Allocation and Check*/
     38  phi = (double *)calloc(num, sizeof(double));
     39  if (phi == (double *)NULL){
     40    printf("Memory Allocation Failed\n");
     41    exit(-1);   
     42  }
     43 
     44  rhs = (double *)calloc(num, sizeof(double));
     45  if (rhs == (double *)NULL){
     46    printf("Memory Allocation Failed\n");
     47    exit(-1);   
     48  } 
     49 
     50  /** Setup **/
     51  dx = 1.0 / (double)(num - 1);
     52  for (i = 0 ; i < num ; i++){
     53    rhs[i] = -dx * dx / d * (dx * (double)i);
     54    phi[i] = 0.0;
     55  }
     56 
     57  /* Boundary Condition*/
     58  phi[0] = a;
     59  phi[num-1] = b;
     60 
     61  /* Solve with SOR Method*/
     62  itc = 0;
     63  while(1){
     64    /* update phi   &  Check Convergence */
     65    merr = 0.0;   
     66    for (i = 1 ; i < (num - 1) ; i++){
     67      w = -0.5 * (rhs[i] - phi[i + 1] - phi[i - 1]);
     68      err = fabs(w - phi[i]);     
     69      phi[i] += rlx * (w - phi[i]);
     70      if (merr < err) merr = err;
     71    }
     72 
     73    itc++;
     74    if (merr < tol) break;
     75    if ((itc % 100) == 0) printf("itc=%d err=%e\n",itc,merr);
     76  }
     77 
     78  printf("Number of Iteration=%d\n",itc);
     79 
     80  /* Output Result */
     81  fp = fopen("res.dat","w");
     82  if (fp == NULL){
     83    printf("File could not create\n");
     84    exit(-1);
     85  }
     86 
     87  for (i = 0 ; i < num ; i++){
     88    fprintf(fp,"%e %e\n",dx * (double)i,phi[i]);
     89  }
     90  fclose(fp);
     91 
     92  /* END : Deallocate Memory */
     93  free(phi);
     94  free(rhs);
     95  printf("Done\n");
     96}
     97}}}