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src/3d/equations/euler/rprhok/rpn3eurhok.f

c
c =========================================================
      subroutine rpn3eurhok(ixyz,maxm,meqn,mwaves,mbc,mx,ql,qr,maux,
     &     auxl,auxr,wave,s,amdq,apdq)
c =========================================================
c
c     # solve Riemann problems for the 3D Euler equations of multiple 
c     # thermally perfect gases a using Roe-type approximate Riemann solver.  
c
c     # On input, ql contains the state vector at the left edge of each cell
c     #           qr contains the state vector at the right edge of each cell
c     # This data is along a slice in the x-direction if ixyz=1
c     #                               the y-direction if ixyz=2.
c     #                               the z-direction if ixyz=3.
c
c     # On output, wave contains the waves, 
c     #            s the speeds, 
c     #            amdq the  left-going flux difference  A^- \Delta q
c     #            apdq the right-going flux difference  A^+ \Delta q
c
c     # Note that the i'th Riemann problem has left state qr(i-1,:)
c     #                                    and right state ql(i,:)
c     # From the basic routines, this routine is called with ql = qr
c
c     # Copyright (C) 2002 Ralf Deiterding, Georg Bader
c     # Brandenburgische Universitaet Cottbus
c
      implicit double precision (a-h,o-z)
c
      include "ck.i"
c
      dimension wave(1-mbc:maxm+mbc, meqn, mwaves)
      dimension    s(1-mbc:maxm+mbc, mwaves)
      dimension   ql(1-mbc:maxm+mbc, meqn)
      dimension   qr(1-mbc:maxm+mbc, meqn)
      dimension apdq(1-mbc:maxm+mbc, meqn)
      dimension amdq(1-mbc:maxm+mbc, meqn)
      dimension auxl(1-mbc:maxm+mbc, maux, 3)
      dimension auxr(1-mbc:maxm+mbc, maux, 3)
c
c     local arrays -- common block comroe is passed to rpt3eurhok
c     ------------
      parameter (maxmrp = 1005) !# assumes atmost max(mx,my,mz) = 1000 with mbc=5
      parameter (minmrp = -4)   !# assumes at most mbc=5
      common /comroe/ u(minmrp:maxmrp), v(minmrp:maxmrp), 
     &     w(minmrp:maxmrp), u2v2w2(minmrp:maxmrp), 
     &     enth(minmrp:maxmrp), a(minmrp:maxmrp), 
     &     g1a2(minmrp:maxmrp), dpY(minmrp:maxmrp), 
     &     Y(LeNsp,minmrp:maxmrp), pk(LeNsp,-1:maxmrp) 
      logical efix
      double precision Cp
c
c     define local arrays
c
      dimension delta(LeNsp+4)
      dimension rkl(LeNsp), rkr(LeNsp)
      dimension hkl(LeNsp), hkr(LeNsp)
c
      data efix /.true./       !# use entropy fix for transonic rarefactions
c
c     # Riemann solver returns flux differences
c     ------------
      common /rpnflx/ mrpnflx
      mrpnflx = 0
c
      if (minmrp.gt.1-mbc .or. maxmrp .lt. maxm+mbc) then
	 write(6,*) 'need to increase maxmrp in rpA'
	 stop
      endif
c
c
c     # set mu to point to  the component of the system that corresponds
c     # to momentum in the direction of this slice, mv and mw to the 
c     # orthogonal momentums:
c
      if(ixyz .eq. 1)then
	  mu = Nsp+1
	  mv = Nsp+2
          mw = Nsp+3
      else if(ixyz .eq. 2)then
	  mu = Nsp+2
	  mv = Nsp+3
          mw = Nsp+1
      else
          mu = Nsp+3
          mv = Nsp+1
          mw = Nsp+2
      endif
      mE = Nsp+4
      mT = Nsp+5
c
c     # note that notation for u,v, and w reflects assumption that the 
c     # Riemann problems are in the x-direction with u in the normal
c     # direction and v and w in the orthogonal directions, but with the 
c     # above definitions of mu, mv, and mw the routine also works with 
c     # ixyz=2 and ixyz = 3
c     # and returns, for example, f0 as the Godunov flux g0 for the
c     # Riemann problems u_t + g(u)_y = 0 in the y-direction.
c
c     # compute the Roe-averaged variables needed in the Roe solver.
c     # These are stored in the common block comroe since they are
c     # later used in routine rpt3eurhok to do the transverse wave splitting.
c
      do 20 i=2-mbc,mx+mbc
         rhol = 0.d0
         rhor = 0.d0
         do k = 1, Nsp
            rkl(k) = qr(i-1,k)
            rkr(k) = ql(i  ,k)
            rhol = rhol + rkl(k)
            rhor = rhor + rkr(k)
         enddo
         if( rhol.le.1.d-10 ) then
            write(6,*) 'negative total density, left', rhol
            stop
         endif
         if( rhor.le.1.d-10 ) then
            write(6,*) 'negative total density, right', rhor
            stop
         endif
c
c        # compute left/right rho/W and rho*Cp
c     
         rhoWl = 0.d0
         rhoWr = 0.d0
         do k = 1, Nsp
            rhoWl = rhoWl + rkl(k)/Wk(k)
            rhoWr = rhoWr + rkr(k)/Wk(k)
         enddo
c
c        # left/right Temperatures already calculated
c
         rhoel = qr(i-1,mE)-0.5d0*
     &        (qr(i-1,mu)**2+qr(i-1,mv)**2+qr(i-1,mw)**2)/rhol
         call SolveTrhok(qr(i-1,mT),rhoel,rhoWl,rkl,Nsp,ifail) 
         rhoer = ql(i  ,mE)-0.5d0*
     &        (ql(i  ,mu)**2+ql(i  ,mv)**2+ql(i  ,mw)**2)/rhor
         call SolveTrhok(ql(i  ,mT),rhoer,rhoWr,rkr,Nsp,ifail) 
c
         Tl = qr(i-1,mT)
         Tr = ql(i  ,mT)
         pl = rhoWl*RU*Tl 
         pr = rhoWr*RU*Tr
c
c       # compute quantities for rho-average
c
         rhsqrtl = dsqrt(rhol)  
         rhsqrtr = dsqrt(rhor)
         rhsq2 = rhsqrtl + rhsqrtr
c
c        # find rho-averaged specific velocity and enthalpy
c
         u(i) = (qr(i-1,mu)/rhsqrtl + ql(i,mu)/rhsqrtr) / rhsq2
         v(i) = (qr(i-1,mv)/rhsqrtl + ql(i,mv)/rhsqrtr) / rhsq2
         w(i) = (qr(i-1,mw)/rhsqrtl + ql(i,mw)/rhsqrtr) / rhsq2
	 u2v2w2(i) = u(i)**2 + v(i)**2 + w(i)**2
         enth(i) = (((qr(i-1,mE)+pl)/rhsqrtl
     &             + (ql(i  ,mE)+pr)/rhsqrtr)) / rhsq2  
c
c        # compute rho-averages for T, cp, and W
c
         T  = (Tl * rhsqrtl + Tr * rhsqrtr) / rhsq2
         Wm = rhsq2 / (rhoWl/rhsqrtl + rhoWr/rhsqrtr) 
c        
c        # evaluate left/right entropies and mean cp
c
         call tabintp( Tl, hkl, hms, Nsp )
         call tabintp( Tr, hkr, hms, Nsp )
         do k = 1, Nsp
            Y(k,i) = (rkl(k)/rhsqrtl + rkr(k)/rhsqrtr) / rhsq2
         enddo
c         
         Cp = Cpmix( Tl, Tr, hkl, hkr, Y(1,i) )
         gamma1 = RU / ( Wm*Cp - RU )
         gamma  = gamma1 + 1.d0
c
c        # find rho-averaged specific enthalpies,
c        # compute rho-averaged mass fractions and
c        # compute partial pressure derivatives
c
         tmp = gamma * RU * T / gamma1 
         ht = 0.d0
         do k = 1, Nsp
            hk     = (hkl(k)*rhsqrtl + hkr(k)*rhsqrtr) / rhsq2
            pk(k,i) = 0.5d0*u2v2w2(i) - hk + tmp / Wk(k)
         enddo
c
c        # compute speed of sound
c
         dpY(i) = 0.d0
         do k = 1, Nsp
            dpY(i) = dpY(i) + pk(k,i) * Y(k,i)
         enddo
         a2 = dpY(i) + enth(i)-u2v2w2(i)
         g1a2(i) = 1.d0 / a2
         a(i) = dsqrt(gamma1*a2) 
c     
   20    continue
c
c
      do 30 i=2-mbc,mx+mbc
c
c        # find a1 thru a5, the coefficients of the Nsp+4 eigenvectors:
c
         dpdr = 0.d0
         drho = 0.d0
         do k = 1, Nsp
            delta(k) = ql(i,k) - qr(i-1,k)
            drho = drho + delta(k)
            dpdr = dpdr + pk(k,i) * delta(k)
         enddo
         delta(mu) = ql(i,mu) - qr(i-1,mu)
         delta(mv) = ql(i,mv) - qr(i-1,mv)
         delta(mw) = ql(i,mw) - qr(i-1,mw)
         delta(mE) = ql(i,mE) - qr(i-1,mE)
c
         a2 = g1a2(i)*(dpdr - ( u(i)*delta(mu) + v(i)*delta(mv) + 
     &        w(i)*delta(mw) ) + delta(mE) )
         a3 = delta(mv) - v(i)*drho
         a4 = delta(mw) - w(i)*drho
         a5 = 0.5d0*( a2 - ( u(i)*drho - delta(mu) )/a(i) )
         a1 = a2 - a5 
c
c        # Compute the waves.
c        # Note that the 1+k-waves, for 1 .le. k .le. Nsp travel at
c        # the same speed and are lumped together in wave(.,.,2).
c        # The 3-wave is then stored in wave(.,.,3).
c
         do k = 1, Nsp
c         # 1-wave
            wave(i,k,1) = a1*Y(k,i)
c         # 2-wave
            wave(i,k,2) = delta(k) - Y(k,i)*a2
c         # 3-wave
            wave(i,k,3) = a5*Y(k,i)
         enddo
 
c      # 1-wave
         wave(i,mu,1) = a1*(u(i) - a(i))
         wave(i,mv,1) = a1*v(i)
         wave(i,mw,1) = a1*w(i)
         wave(i,mE,1) = a1*(enth(i) - u(i)*a(i))
         wave(i,mT,1) = 0.d0
         s(i,1) = u(i)-a(i)
c
c      # 2-wave
         wave(i,mu,2) = (drho - a2)*u(i)
         wave(i,mv,2) = (drho - a2)*v(i) + a3
         wave(i,mw,2) = (drho - a2)*w(i) + a4
         wave(i,mE,2) = (drho - a2)*u2v2w2(i) 
     &        - dpdr + dpY(i)*a2         + a3*v(i) + a4*w(i)
         wave(i,mT,2) = 0.d0
         s(i,2) = u(i)
c
c      # 3-wave
         wave(i,mu,3) = a5*(u(i) + a(i))
         wave(i,mv,3) = a5*v(i)
         wave(i,mw,3) = a5*w(i)
         wave(i,mE,3) = a5*(enth(i) + u(i)*a(i))
         wave(i,mT,3) = 0.d0
         s(i,3) = u(i)+a(i)
c                  
   30 continue
c
c     # compute Godunov flux f0:
c     --------------------------
c
c
      if (efix) go to 110
c
c     # no entropy fix
c     ----------------
c
c     # amdq = SUM s*wave   over left-going waves
c     # apdq = SUM s*wave   over right-going waves
c
      do 100 m=1,meqn
         do 100 i=2-mbc, mx+mbc
            amdq(i,m) = 0.d0
            apdq(i,m) = 0.d0
            do 90 mws=1,mwaves
               if (s(i,mws) .lt. 0.d0) then
                  amdq(i,m) = amdq(i,m) + s(i,mws)*wave(i,m,mws)
               else
                  apdq(i,m) = apdq(i,m) + s(i,mws)*wave(i,m,mws)
               endif
   90       continue
  100 continue
      go to 900
  110 continue
c
c     # With entropy fix
c     ------------------
c
c    # compute flux differences amdq and apdq.
c    # First compute amdq as sum of s*wave for left going waves.
c    # Incorporate entropy fix by adding a modified fraction of wave
c    # if s should change sign.
c
      do 200 i=2-mbc,mx+mbc
c
c        # check 1-wave:
c        ---------------
c
         rhol  = 0.d0
         rhoWl = 0.d0
         do k = 1, Nsp
            rkl(k) = qr(i-1,k)
            rhol   = rhol  + rkl(k)
            rhoWl  = rhoWl + rkl(k)/Wk(k)
         enddo
         rhou  = qr(i-1,mu)
         rhov  = qr(i-1,mv)
         rhow  = qr(i-1,mw)
         rhoE  = qr(i-1,mE)
         T     = qr(i-1,mT)
         rhoCp = avgtabip( T, rkl, cpk, Nsp )
         gamma = RU / ( rhoCp/rhoWl - RU ) + 1.d0
         p = rhoWl*RU*T
         c = dsqrt(gamma*p/rhol)
         s0 = rhou/rhol - c     !# u-c in left state (cell i-1)
*        write(6,*) 'left state 0', a(i), c, T
c 
c        # check for fully supersonic case:
         if (s0.ge.0.d0 .and. s(i,1).gt.0.d0)  then
c           # everything is right-going
            do 60 m=1,meqn
               amdq(i,m) = 0.d0
   60       continue
            go to 200
         endif
c
         rhol   = 0.d0
         rhoWl  = 0.d0
         do k = 1, Nsp
            rkl(k) = rkl(k) + wave(i,k,1)
            rhol   = rhol   + rkl(k)
            rhoWl  = rhoWl  + rkl(k)/Wk(k)
         enddo
         rhou = rhou + wave(i,mu,1)
         rhov = rhov + wave(i,mv,1)
         rhow = rhow + wave(i,mw,1)
         rhoE = rhoE + wave(i,mE,1)
         rhoe  = rhoE - 0.5d0*(rhou**2+rhov**2+rhow**2)/rhol
         if ( TabS.gt.T*TABFAC .or. T*TABFAC.gt.TabE ) then
             write(6,*) 'Temperature out of range', T
             write(6,*) 'state vector 1 before'
             write(6,*) (rkl(k),k=1,Nsp)
         endif
         call SolveTrhok( T, rhoe, rhoWl, rkl, Nsp, ifail)
         rhoCp = avgtabip( T, rkl, cpk, Nsp )
         if ( TabS.gt.T*TABFAC .or. T*TABFAC.gt.TabE ) then
             write(6,*) 'Temperature out of range', T
             write(6,*) 'state vector 1 after'
             write(6,*) (rkl(k),k=1,Nsp)
         endif
         gamma = RU / ( rhoCp/rhoWl - RU ) + 1.d0
         p = rhoWl*RU*T
         c = dsqrt(gamma*p/rhol)
         s1 = rhou/rhol - c  !# u-c to right of 1-wave
*        write(6,*) 'left state 1', a(i), c, T
c
         if (s0.lt.0.d0 .and. s1.gt.0.d0) then
c            # transonic rarefaction in the 1-wave
             sfract = s0 * (s1-s(i,1)) / (s1-s0)
           else if (s(i,1) .lt. 0.d0) then
c            # 1-wave is leftgoing
             sfract = s(i,1)
           else
c            # 1-wave is rightgoing
             sfract = 0.d0   !# this shouldn't happen since s0 < 0
           endif
         do 120 m=1,meqn
            amdq(i,m) = sfract*wave(i,m,1)
  120    continue 
c
c        # check 2-wave:
c        ---------------
c
         if (s(i,2) .ge. 0.d0) go to 200  !# 2-wave is rightgoing
         do 140 m=1,meqn
            amdq(i,m) = amdq(i,m) + s(i,2)*wave(i,m,2)
  140    continue
c
c        # check 3-wave:
c        ---------------
c
         rhor  = 0.d0
         rhoWr = 0.d0
         do k = 1, Nsp
            rkr(k) = ql(i,k)
            rhor   = rhor   + rkr(k)
            rhoWr  = rhoWr  + rkr(k)/Wk(k)
         enddo
         rhou  = ql(i,mu)
         rhov  = ql(i,mv)
         rhow  = ql(i,mw)
         rhoE  = ql(i,mE)
         T     = ql(i,mT)
         rhoCp = avgtabip( T, rkr, cpk, Nsp )
         gamma = RU / ( rhoCp/rhoWr - RU ) + 1.d0
         p = rhoWr*RU*T
         c = dsqrt(gamma*p/rhor)
         s3 = rhou/rhor + c     !# u+c in right state  (cell i)
*        write(6,*) 'right state 1', a(i), c, T
c          
         rhor  = 0.d0
         rhoWr = 0.d0
         do k = 1, Nsp
            rkr(k) = rkr(k) - wave(i,k,3)
            rhor   = rhor   + rkr(k)
            rhoWr  = rhoWr  + rkr(k)/Wk(k)
         enddo
         rhou  = rhou - wave(i,mu,3)
         rhov  = rhov - wave(i,mv,3)
         rhow  = rhow - wave(i,mw,3)
         rhoE  = rhoE - wave(i,mE,3)
         rhoe  = rhoE - 0.5d0*(rhou**2+rhov**2+rhow**2)/rhor
         if ( TabS.gt.T*TABFAC .or. T*TABFAC.gt.TabE ) then
             write(6,*) 'Temperature out of range', T
             write(6,*) 'state vector 1 before'
             write(6,*) (rkr(k),k=1,Nsp)
         endif
         call SolveTrhok( T, rhoe, rhoWr, rkr, Nsp, ifail)
         rhoCp = avgtabip( T, rkr, cpk, Nsp )
         if ( TabS.gt.T*TABFAC .or. T*TABFAC.gt.TabE ) then
             write(6,*) 'Temperature out of range', T
             write(6,*) 'state vector 1 after'
             write(6,*) (rkr(k),k=1,Nsp)
         endif
         gamma = RU / ( rhoCp/rhoWr - RU ) + 1.d0
         p = rhoWr*RU*T
         c = dsqrt(gamma*p/rhor)
         s2 = rhou/rhor + c   !# u+c to left of 3-wave
*        write(6,*) 'right state 0', a(i), c, T
c
         if (s2 .lt. 0.d0 .and. s3.gt.0.d0) then
c            # transonic rarefaction in the 3-wave
             sfract = s2 * (s3-s(i,3)) / (s3-s2)
           else if (s(i,3) .lt. 0.d0) then
c            # 3-wave is leftgoing
             sfract = s(i,3)
           else
c            # 3-wave is rightgoing
             go to 200
           endif
c
         do 160 m=1,meqn
            amdq(i,m) = amdq(i,m) + sfract*wave(i,m,3)
  160    continue
  200 continue
c
c     # compute the rightgoing flux differences:
c     # df = SUM s*wave   is the total flux difference and apdq = df - amdq
c
      do 220 m=1,meqn
         do 220 i = 2-mbc, mx+mbc
            df = 0.d0
            do 210 mws=1,mwaves
               df = df + s(i,mws)*wave(i,m,mws)
  210       continue
            apdq(i,m) = df - amdq(i,m)
  220 continue 
c
  900 continue
c
      return
      end
c
c
c  ***********************************************************
c
      double precision function Cpmix( Tl, Tr, hl, hr, Y )
      implicit double precision(a-h,o-z)
      include  "ck.i"
c
      dimension Y(*)
      dimension hl(*), hr(*)
      data Tol /1.d-6/
c
      if( dabs(Tr-Tl).gt.Tol ) then
         Cp = 0.d0
         do k = 1, Nsp
            Cp = Cp + (hr(k)-hl(k)) * Y(k) 
         enddo
         Cp = Cp / (Tr-Tl)
      else
         T = 0.5d0*(Tr+Tl)
         Cp = avgtabip( T, Y, cpk, Nsp )
      endif
      Cpmix = Cp
c
      return
      end

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