Changes between Initial Version and Version 1 of cypress/Programming/HeatMassTransfer/ex23.c

Timestamp:

05/14/15 15:23:55 (9 years ago)

Author:

cmaggio

Comment:

migrated content from ccs wiki

cypress/Programming/HeatMassTransfer/ex23.c

@@ +1 @@
+= Ex23.c =
+{{{#!C
+/*
+  Large Scale Computing
+  Convective Heat/Mass Transfer
+  ex23.c : Gauss-Seidel 
+ 
+  duphi/dx = d2phi/dx2
+ */
+#include<stdio.h>
+#include<stdlib.h>
+#include<math.h>
+ 
+/* min and max macros */
+#define max(a,b)        (((a) > (b)) ? (a) : (b))
+#define min(a,b)        (((a) < (b)) ? (a) : (b))
+ 
+int main(int argc, char **argv){
+  double a,b,d,u;
+  double *phi;
+  double w;
+  double dx,x,sol;
+  double err;
+  double ae,aw,ap;
+  double tol = 1.0e-10;
+  int i,num,itc;
+  FILE *fp;
+ 
+  if (argc < 6){
+    printf("Usage:%s [NUM] [A] [B] [D] [U]\n",argv[0]);
+    exit(-1);
+  }
+ 
+  /* set parameters */
+  num = atoi(argv[1]);
+  a = atof(argv[2]);
+  b = atof(argv[3]);
+  d = atof(argv[4]);
+  u = atof(argv[5]);
+ 
+  printf("num=%d A=%e B=%e D=%e U=%e\n",num,a,b,d,u);
+ 
+  /* Memory Allocation and Check*/
+  phi = (double *)calloc(num, sizeof(double));
+  if (phi == (double *)NULL){
+    printf("Memory Allocation Failed\n");
+    exit(-1);    
+  }
+ 
+  /** Setup **/
+  dx = 1.0 / (double)(num - 1);
+  for (i = 0 ; i < num ; i++){
+    phi[i] = 0.0;
+  }
+  ae = d / dx + max(-u,0.0);
+  aw = d / dx + max(u,0.0);
+  ap = ae + aw;
+ 
+  /* Boundary Condition*/
+  phi[0] = a;
+  phi[num-1] = b;
+ 
+  /* Solve with Gauss-Seidel Method*/
+  itc = 0;
+  while(1){
+    /* update phi   &  Check Convergence */
+    err = 0.0;    
+    for (i = 1 ; i < (num - 1) ; i++){
+      w =  (ae *  phi[i + 1] + aw *  phi[i - 1]) / ap;
+      err += (w - phi[i]) * (w - phi[i]);      
+      phi[i] = w;
+    }
+ 
+    itc++;
+    if (err < tol) break;
+    if ((itc % 100) == 0) printf("itc=%d err=%e\n",itc,err);
+  }
+ 
+  printf("Number of Iteration=%d\n",itc);
+ 
+  /* Output Result */
+  fp = fopen("res.dat","w");
+  if (fp == NULL){
+    printf("File could not create\n");
+    exit(-1);
+  }
+ 
+  for (i = 0 ; i < num ; i++){
+    x = dx * (double)i;
+    sol = a + (b - a) * (exp(x * u / d) - 1.0) / (exp(u / d) - 1.0);
+    fprintf(fp,"%e %e %e\n",x,phi[i],sol);
+  }
+  fclose(fp);
+ 
+  /* END : Deallocate Memory */
+  free(phi);
+  printf("Done\n");
+}
+}}}