c
c Boundary conditions for ghost-fluid methods.
c
c Copyright (C) 2003-2007 California Institute of Technology
c Ralf Deiterding, ralf@amroc.net
c
c -----------------------------------------------------
c Internal reflecting physical boundary conditions
c for Euler equations
c -----------------------------------------------------
c
c Transformation of vector of conserved quantities
c into primitives (rho1,rho2,u,v,p)
c
c =====================================================
subroutine it2euzndrfl(mx,my,meqn,q,qt)
c =====================================================
implicit none
c
common /param/ gamma,gamma1,q0
double precision gamma,gamma1,q0
integer i, j, mx, my, meqn
double precision q(meqn,mx,my), qt(meqn,mx,my)
c
do 10 j = 1, my
do 10 i = 1, mx
qt(1,i,j) = q(1,i,j)
qt(2,i,j) = q(2,i,j)
qt(3,i,j) = q(3,i,j)/(q(1,i,j)+q(2,i,j))
qt(4,i,j) = q(4,i,j)/(q(1,i,j)+q(2,i,j))
qt(5,i,j) = gamma1*(q(5,i,j) - q(2,i,j)*q0 -
& 0.5d0*(q(3,i,j)**2 + q(4,i,j)**2)/(q(1,i,j)+q(2,i,j)))
10 continue
c
return
end
c
c -----------------------------------------------------
c
c Construction of reflective boundary conditions from
c mirrored primitive values and application in
c conservative form in local patch
c
c =====================================================
subroutine ip2euzndrfl(q,mx,my,lb,ub,meqn,nc,idx,
& qex,xc,phi,vn,maux,auex,dx,time)
c =====================================================
implicit none
common /param/ gamma,gamma1,q0
double precision gamma,gamma1,q0
integer mx, my, meqn, maux, nc, idx(2,nc), lb(2),
& ub(2)
double precision q(meqn, mx, my), qex(meqn,nc), xc(2,nc),
& phi(nc), vn(2,nc), auex(maux,nc), dx(2), time
c
c Local variables
c
integer i, j, n, stride, getindx
double precision rho1, rho2, u, v, p, vl
c
stride = (ub(1) - lb(1))/(mx-1)
c
do 100 n = 1, nc
i = getindx(idx(1,n), lb(1), stride)
j = getindx(idx(2,n), lb(2), stride)
c
rho1 = qex(1,n)
rho2 = qex(2,n)
u = -qex(3,n)
v = -qex(4,n)
p = qex(5,n)
c
c # Add boundary velocities if available
if (maux.ge.2) then
u = u + auex(1,n)
v = v + auex(2,n)
endif
c
c # Construct normal velocity vector
c # Tangential velocity remains unchanged
vl = 2.d0*(u*vn(1,n)+v*vn(2,n))
u = qex(3,n) + vl*vn(1,n)
v = qex(4,n) + vl*vn(2,n)
c
q(1,i,j) = rho1
q(2,i,j) = rho2
q(3,i,j) = u*(rho1+rho2)
q(4,i,j) = v*(rho1+rho2)
q(5,i,j) = p/gamma1+0.5d0*(rho1+rho2)*(u**2+v**2)+rho2*q0
c
100 continue
c
return
end
c
c
c -----------------------------------------------------
c
c Injection of conservative extrapolated values in local patch
c
c =====================================================
subroutine ip2euzndex(q,mx,my,lb,ub,meqn,nc,idx,
& qex,xc,phi,vn,maux,auex,dx,time)
c =====================================================
c
implicit none
c
common /param/ gamma,gamma1,q0
double precision gamma,gamma1,q0
integer mx, my, meqn, maux, nc, idx(2,nc), lb(2),
& ub(2)
double precision q(meqn, mx, my), qex(meqn,nc), xc(2,nc),
& phi(nc), vn(2,nc), auex(maux,nc), dx(2), time
c
c Local variables
c
integer i, j, n, stride, getindx
double precision rho1, rho2, u, v, p, vl
c
stride = (ub(1) - lb(1))/(mx-1)
c
do 100 n = 1, nc
i = getindx(idx(1,n), lb(1), stride)
j = getindx(idx(2,n), lb(2), stride)
c
rho1 = qex(1,n)
rho2 = qex(2,n)
u = qex(3,n)
v = qex(4,n)
p = qex(5,n)
c
c # Prescribe normal velocity vector
vl = u*vn(1,n)+v*vn(2,n)
u = vl*vn(1,n)
v = vl*vn(2,n)
c
q(1,i,j) = rho1
q(2,i,j) = rho2
q(3,i,j) = u*(rho1+rho2)
q(4,i,j) = v*(rho1+rho2)
q(5,i,j) = p/gamma1+0.5d0*(rho1+rho2)*(u**2+v**2)+rho2*q0
c
100 continue
c
return
end
c