VGRID Files

The following is description of grid files generated with VGRID. 
For most solvers, only mapbc, bc, and cogsg files are needed.
 
------------------------------------------------------------

  1)  project.mapbc:  Patch/flow-boundary-condition file (ASCII)

                    ----------format------------
c
       parameter(mpatch=***)
c
       integer bcpch(mpatch)
       character*1 text(80)
c
       open(13,file='project.mapbc',form='formatted')
c
       read(13,900)text
       read(13,900)text
       read(13,900)text
       read(13,900)text
       do ipatch=1,npatch
        read(13,*)jpatch,bcpch(ipatch),idum1,idum2,idum3
       enddo
c
  900 format(80a1)
c
                   ----------------------------

  where

       text = text line
     npatch = number of surface patches defining the geometry
     jpatch = surface patch index
      bcpch = flow boundary condition assigned to surface patch "jpatch"
      idum1,idum2,idum3 = dummy variables


**********************************************************************


  2)  project.bc: patch/surface-triangle file (ASCII)

                   ----------format-------------
c
       parameter(mbf=***)
c
       integer fapch(mbf),fnode(mbf,3)
       character*1 text(80)
c
       open(unit=12,file='project.bc',form='formatted')
c
       read(12,*)nbf,nbc,npatch,igrid
       read(12,900)text
       do if=1,nbf
        read(12,*)jf,fapch(if),fnode(if,in),in=1,3)
       enddo
  900  format(80a1)
c
                   ----------------------------

  where

        nbf = number of boundary triangular faces
        nbc = number of surface grid nodes along patch boundaries (curves)
     npatch = number of surface patches
      igrid = 1 for inviscid grids; 2 for viscous grids
       text = text line
         jf = triangle index
  fapch(if) = surface patch index containing surface triangle "if"
fnode(if,in) = node "in" of triangle "if"

Note: triangle connectivities are according to the right-hand rule with
      the outward normals pointing into the computational domain.

***********************************************************************


  3)  project.cogsg: x,y,z coordinates of the grid nodes and
                    tetrahedral node connectivity

                   ----------format------------
c
      parameter(mp=***, mc=***)   !maximum number of grid nodes and cells
      real(8)  crd(mp,3),t
      integer int(mc,4)
c
       open(9,file='project.cogrd',form='unformatted',iostat=ios,
     &      err=555,status='old')
c
      npoic=0
      npois=1
      nelec=0
      neles=1
      read(9)inew,nc,npo,nbn,npv,nev,t,
     &       ((int(ie,in),ie=neles,nelee),in=1,4)
      read(9)((crd(ip,id),ip=npois,npoie),id=1,3)
      nelec=nelee
      npoic=npoie
c
 100  continue
      neles=neles+nelec
      read(9,end=400)nelec
      if(nelec .eq. 0) goto 400
      nelee=neles+nelec-1
      read(9)((int(ie,in),ie=neles,nelee),in=1,4)
      npois=npois+npoic
      read(9)npoic
      npoie=npois+npoic-1
      read(9)((crd(ip,id),ip=npois,npoie),id=1,3)
c
      goto 100
 400  continue
      npo=npoie
      nc=nelee
c
                   ----------------------------

  where

         inew = a dummy variable (integer)
           nc = number of tetrahedral cells
          npo = total number of grid nodes (including nbn)
          nbn = number of grid nodes on the boundaries (including nbc)
          npv = number of grid points in the viscous layers
                (=0 for Euler grids)
          ncv = number of cells in the viscous layers
                (=0 for Euler grids)
            t = a dummy variable (real - double)
   int(ie,in) = tetradhedral cell connectivity
                (node "in" of cell "ie")
   crd(ip,id) = x, y, and z coordinates of node "ip"

  Note 1: the first "nbn" coordinates listed in this file are those of
         the boundary nodes.

  Note 2:  tetrahedral cell connectivities are given according to the
           right-hand rule (3 nodes of the base in the counter-clockwise
           direction followed by the 4th node.)

************************************************************************

  4) project.poin1: field nodes in the B.L. linked to the surface 
                   mesh nodes (ASCII)

                     ---------format----------
       parameter(mp=***)
c
       integer lpoin(mp)
c
       open(14,file='project.poin1',form='formatted')
c
       read(14,*)nbn,npv
       do ip=1,npv
         read(14,*)jp,lpoin(ip)
       enddo
                        ---------------------

 where

      nbn = number of grid nodes on the boundaries
      npv = number of grid nodes inside the boundary layer (including nbn)
       jp = node index
lpoin(ip) = surface node linked to the field node "ip"

 Note 1: "viscous" field nodes are generated along rays emanating from
          the surface mesh nodes. lpoin gives the corresponding surface
          node index for each viscous field node along the ray.

 Note 2: lpoin(ip) = ip, for ip=1,nbn (surface mesh nodes).

************************************************************************