Commit: 727dc8134c56c86dcd2a03b18953211cd5fb1786 - myprojects-hg-reborn (hg)

Commit MetaInfo

• Revisão: 727dc8134c56c86dcd2a03b18953211cd5fb1786 (tree)
• Hora: 2006-12-30 10:36:13
• Autor: iselllo
• Commiter: iselllo

Mensagem de Log

I modified the file secdml.f in directory CODESCH2/SECD of the diskette
folder by adding my own comments to the code.

Mudança Sumário

• modified: diskette/CODESCH2/SECD/secdml.f

Diff

diff -r 5702faceee64 -r 727dc8134c56 diskette/CODESCH2/SECD/secdml.f
--- a/diskette/CODESCH2/SECD/secdml.f	Wed Dec 27 23:06:12 2006 +0000
+++ b/diskette/CODESCH2/SECD/secdml.f	Sat Dec 30 01:36:13 2006 +0000
@@ -5,6 +5,38 @@
 c     IN this code a function appropriate for a mixing
 c     layer is used
 c                                                                       
+    
+
+c ##########################################################################
+c ##########################################################################
+c ##########################################################################
+C Now I add my own comments to the code.
+c the array y(i) contains the physical grid (which is called x(csi) in the book 
+c by Orlandi.
+
+c in the code, dx=1/(delta csi) and dxq=1/(delta csi)^2, if one wants to use the 
+c notation by Orlandi. 
+c the grid coord csi is in the interval [0,1].
+c n1 is the total number of points I use to break up [0,1] into subintervals.
+c n1m=n1-1 is the total number of subinterval I create this way, which means that
+c delta csi=1/n1m. 
+c Basically, n1 is the parameter which determines the accuracy of the computational
+c grid.
+
+
+c in most of the cases, when saving data, one rules out the case corresponding to
+c y(i)=0, which is the boundary and which requires a separate treatment.
+
+c finally, yprer is a particular value of y(i) for which some data are saved in the file
+c accuracy.plo
+
+
+c al end alfu correspond to alpha and alpha_u, respectively
+c They play a role in the definition of the initial velocity profile and in the 
+c case of the transformation relating physical and computational coord.
+c (see eqs. 2.19 and 2.24 in the book by Orlandi).
+
+
       include 'param.f'
       character *60 namfile
       write(6,*)'enter alfu, al, yprer'
@@ -66,12 +98,19 @@
       er3=0.
                             endif
       if(y(i).ge.0.) then
-      write(16,794)csi,er1,er2,er3                                      
+      write(16,794)csi,er1,er2,er3   
+c   the previous write(16,794) writes to file number 16 i.e. to 'errdis'//npoi//'.plo'    
+c NB: the data are saved for y(i)>0 which means int turn csi>0.5 (see the book by Orlandi).
+                             
       write(17,794)csi,sd1(i),sd2(i),sda(i)                             
+c this write(17,794) will write the data to file Fort.17
                      endif
       if(y(i).ge.yprer.and.y(i-1).le.yprer) then
       write(20,794) an1,er1,er2,er3
                                             endif
+c this write(20,794) writes the data to file accuracy.plo (actually, the condition
+c required is verified at for a single i 
+
  794  format(4x,6e12.5)                                  
       enddo
       return                                                            
@@ -118,6 +157,11 @@
       enddo
       return                                                            
       end                                                               
+
+
+c u(i) defined above is simply the initial velocity profile for a mixing layer
+c (see eqs 2.19 in the book by Orlandi).
+
 c                                                                       
 c                                                                       
 c     **********************************************************        
@@ -145,6 +189,10 @@
       write(9,110)csi,y(i)
   110 format(5e12.5)
       enddo
+
+c the array y(i) which has been defined above is simply the physical grid (see
+c equation 2.24 in the book by Orlandi. Here (and in the book) h is taken to be 
+c 1 so it does not appear.
 c                                                                       
       do i=1,n1m                                                     
       csi=(i-1+0.5)/float(n1m)                                   
@@ -159,6 +207,12 @@
 c                                                                       
       return                                                            
       end                                                               
+
+c dcay and dmay are simply the central and forward derivative (evaluated
+c analytically) of the physical coord wrt the computational coord.
+c The central derivative is evaluated at the computationa grid 
+c point csi, whereas the forward derivative is evaluated in between 2 grid points.
+
 c                                                                       
 c     ***************************************************************   
 c                                                                       
@@ -169,6 +223,14 @@
 c      at the grid points dcy and at the mid points dmy
 c      ddcy is the second derivative of the physical coordinate
 c
+   
+
+c this routine simply works out the 1st and 2nd derivatives of the physical
+c coord wrt the computational coord, but this time this is done numerically
+c using finite-differences.  dcy and dmy are the central and forward first deriva
+c tive, respectively. ddcy is the 2nd derivative evaluated by means of the 
+c central differences.
+
       include 'param.f'
       do i=2,n1m                                                    
       dcy(i)=(y(i+1)-y(i-1))*0.5*dx              
@@ -205,6 +267,9 @@
       sd3(i)=(aa3*u(i+1)+bb3*u(i)+cc3*u(i-1))
       write(63,*)i,sd1(i),sd2(i),sda(i)
       enddo
+c this routine saves the data into files Fort.63 and Fort.64
+
+
 c                                                                       
 c     the solutions are written in a file together
 c     with the exact value