applications/euler/2d/Shockbubble/src/physbd2.f

!-----------------------------------------------------------------------
! Physical boundary conditions
! Interface:
!   mx,my    := shape of grid function
!
!   u(,) := grid function
!
!   lb(2) := lower bound for grid
!   ub(2) := upper bound for grid
!   lbbnd(2) := lower bound for boundary region
!   ubnd(2) := upper bound for boundary region
!   shapebnd(2) := shape of boundary region 
!   xc(2) := lower left corner of grid
!   dx(2) := grid spacing
!   dir := at which side of the grid is the boundary?
!   bnd(,2,2) := lower left and upper right corner of global grid and 
!      of mb-1 internal boundary regions 
!-----------------------------------------------------------------------

      subroutine physbd(u,mx,my,lb,ub,lbbnd,ubbnd,shapebnd,
     &     xc,dx,dir,bnd,mb,time,args,argc)

      implicit double precision (a-h,o-z)
      include  "cuser.i"

      integer   argc, args, mx, my, mb, dir
      integer   lb(2), ub(2), lbbnd(2), ubbnd(2), shapebnd(2)
      real*8    u(args, mx, my), xc(2), dx(2), bnd(mb,2,2), time

!      Local variables
      integer   i, j, imin, imax, jmin, jmax, jsym
      integer   stride, stridebnd, meqn, getindx
      integer   isx(4), isy(4)
c
      data isx /1,-1,1,1/
      data isy /1,1,-1,1/

      meqn = args

!- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
!      See definition of member-function extents() in BBox.h 
!      for calculation of stride
         
      stride = (ub(1) - lb(1))/(mx-1)
      
      if (meqn .ne. 4) then
         write(0,*)'ERROR in physbd: '
      else

!- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
!     Find working domain
         
         imin = getindx(max(lbbnd(1), lb(1)), lb(1), stride)
         imax = getindx(min(ubbnd(1), ub(1)), lb(1), stride)
         
         jmin = getindx(max(lbbnd(2), lb(2)), lb(2), stride)
         jmax = getindx(min(ubbnd(2), ub(2)), lb(2), stride)
         
         if(imax .gt. mx .or. jmax .gt. my .or. 
     &        imin .lt. 1 .or. jmin .lt. 1) then
            write(0,*)'INDEX ERROR in physbd'
         end if

         go to (100,200,300,400) dir+1

!        Left Side --- Inflow
!- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 100     continue
         do 110 i = imax, imin, -1
            if (xc(1)+(i-0.5d0)*dx(1).lt.bnd(1,1,1)) then
               do 120 j = jmin, jmax
                  do 120 m = 1, meqn
                     u(m,i,j) = qinfl(m)
 120           continue
            endif
 110     continue
         return

!        Right Side --- Outflow
!- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 200     continue
         do 210 i = imin, imax
            if (xc(1)+(i-0.5d0)*dx(1).gt.bnd(1,2,1)) then
               do 220 j = jmin, jmax
                  do 220 m = 1, meqn
                     u(m,i,j) = u(m,i-1,j)
 220           continue
            endif
 210     continue
         return
         
!        Bottom Side --- Symmetry
!- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 300     continue
         do 310 j = jmax, jmin, -1
            if (xc(2)+(j-0.5d0)*dx(2).lt.bnd(1,1,2)) then
               jsym = 2*jmax+1-j
               do 320 i = imin, imax
                  do 320 m = 1, meqn
                     u(m,i,j) = u(m,i,jsym)*isy(m)
 320           continue
            endif
 310     continue
         return

!        Top Side --- Reflection
!- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 400     continue
         do 410 j = jmin, jmax
            if (xc(2)+(j-0.5d0)*dx(2).gt.bnd(1,2,2)) then
               do 420 i = imin, imax
                  do 420 m = 1, meqn
                     u(m,i,j) = u(m,i,j-1)
 420           continue
            endif
 410     continue
         return
      endif

      return
      end