!----------------------------------------------------------------------- ! Physical boundary conditions for 1d Euler equations. ! Zero order outflow at both sides. ! Interface: ! mx,my := shape of grid function ! ! u(,) := grid function ! ! lb(1) := lower bound for grid ! ub(1) := upper bound for grid ! lbbnd(1) := lower bound for boundary region ! ubnd(1) := upper bound for boundary region ! shapebnd(1) := shape of boundary region ! xc(1) := lower left corner of grid ! dx(1) := grid spacing ! dir := at which side of the grid is the boundary? ! bnd(,2,1) := lower left and upper right corner of global grid and ! of mb-1 internal boundary regions ! ! Copyright (C) 2002 Ralf Deiterding ! Brandenburgische Universitaet Cottbus ! ! Copyright (C) 2003-2007 California Institute of Technology ! Ralf Deiterding, ralf@cacr.caltech.edu ! !----------------------------------------------------------------------- subroutine physbd(u,mx,lb,ub,lbbnd,ubbnd,shapebnd, & xc,dx,dir,bnd,mb,time,meqn) implicit none integer mb, dir, meqn, mx integer lb(1), ub(1), lbbnd(1), ubbnd(1), shapebnd(1) double precision u(meqn, mx), xc(1), dx(1), bnd(mb,2,1), time ! Local variables integer i, m, imin, imax, isym integer stride, stridebnd, getindx !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! See definition of member-function extents() in BBox.h ! for calculation of stride stride = (ub(1) - lb(1))/(mx-1) !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! Find working domain imin = getindx(max(lbbnd(1), lb(1)), lb(1), stride) imax = getindx(min(ubbnd(1), ub(1)), lb(1), stride) if(imax .gt. mx .or. imin .lt. 1) then write(0,*)'INDEX ERROR in physbd' end if ! Left Side --- Outflow !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - if (dir.eq.0) then do 200 i = imax, imin, -1 do 200 m = 1, meqn u(m,i) = u(m,i+1) 200 continue return end if ! Right Side --- Outflow !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - if (dir.eq.1) then do 210 i = imin, imax do 210 m = 1, meqn u(m,i) = u(m,i-1) 210 continue return end if c return end