Changes between Initial Version and Version 1 of cypress/Programming/HeatMassTransfer/ex17.f90

Timestamp:

05/14/15 15:19:48 (11 years ago)

Author:

cmaggio

Comment:

—

cypress/Programming/HeatMassTransfer/ex17.f90

@@ +1 @@
+= Ex17.f90 =
+{{{#!fortran
+!
+!  Large Scale Computing
+!  2D Heat/Mass Transfer
+!  ex17.f90 : Numerical Analysis
+!  Solve for
+!  d2c/dx2 + d2c/dy2 + 1 = 0
+!  With the boundary conditions of c = 0 
+!  along lines of x=1,-1, and y=1, and -1
+!
+program diffusion2d
+  implicit none
+  integer, parameter ::  NUM=20  ! number of points for x and y
+  double precision, parameter :: TOL=1.0e-12 ! convergence tolerance 
+  integer ::  i,j,k,n,ie,iw,in,is
+  double precision :: x,y,dx,w,err
+  double precision, dimension(NUM * NUM) :: cnc ! define 1D array of length NUM * NUM 
+ 
+  !assuming dx = dy : domain is 2x2 
+  dx = 2.d0 / dble(NUM - 1)
+ 
+  ! Initialize 
+  do n = 1, NUM * NUM 
+     cnc(n) = 0.0;
+  end do
+ 
+  !computing for C with Gauss-Seidel 
+  k = 0
+  do
+    err = 0.d0
+    do n = 1, NUM * NUM
+       i = mod(n - 1,NUM) + 1
+       j = (n - 1) / NUM + 1
+       if (i == 1) cycle !skip left end
+       if (i == NUM) cycle !skip right end
+       if (j == 1) cycle !skip bottom end
+       if (j == NUM) cycle !skip top end
+ 
+       ie = n + 1;
+       iw = n - 1;
+       in = n + NUM;
+       is = n - NUM;
+       w = 0.25 * (dx * dx + cnc(ie) + cnc(iw) + cnc(in) + cnc(is))
+       err = err + (w - cnc(n)) * (w - cnc(n))
+       cnc(n) = w
+    end do
+    k = k + 1
+    if (err < TOL) exit
+ end do
+ print *,"# of Iteration=",k
+ 
+ ! Output Result 
+ open(10,FILE='res.dat')
+ do i = 1,NUM
+    do j = 1,NUM
+       x = -1.0 + 2.0 * dble(i-1) / dble(NUM - 1)
+       y = -1.0 + 2.0 * dble(j-1) / dble(NUM - 1)
+       write(10,'(3e16.8)') x,y,cnc(i + NUM * (j - 1))
+    end do
+ end do
+ close(10)
+ 
+ print *,"Done"
+end program diffusion2d
+}}}