PHOTON USE
  p
  n4
 
 
 
  up z
  msg contours of S at time = 0.1s
  con s1 x 1 sh;.49 .52 40
  msg velocity vectors
  vec x 1
  MSG Press Enter to continue
  pause
  p
  n8
 
 
 
  up z
  msg contours of S at time = 0.20s
  con s1 x 1 sh;.49 .52 40
  msg velocity vectors
  vec x 1
  MSG Press Enter to continue
  pause
  p
  n12
 
 
 
  up z
  msg contours of S at time = 0.35s
  con s1 x 1 sh;.49 .52 40
  msg velocity vectors
  vec x 1
  MSG Press Enter to continue
  pause
  p
  n16
 
 
 
  up z
  msg contours of S at time = 0.40s
  con s1 x 1 sh;.49 .52 40
  msg velocity vectors
  vec x 1
  MSG Press Enter to continue
  pause
  p
  n20
 
 
 
  up z
  msg contours of S at time = 0.50s
  con s1 x 1 sh;.49 .52 40
  msg velocity vectors
  vec x 1
  MSG Press Enter to continue
  pause
  p
  n24
 
 
 
  up z
  msg contours of S at time = 0.60s
  con s1 x 1 sh;.49 .52 40
  msg velocity vectors
  vec x 1
  MSG Press Enter to continue
  pause
  p
  n28
 
 
 
  up z
  msg contours of S at time = 0.70s
  con s1 x 1 sh;.49 .52 40
  msg velocity vectors
  vec x 1
  MSG Press Enter to continue
  pause
  p
  n32
 
 
 
  up z
  msg contours of S at time = 0.80s
  con s1 x 1 sh;.49 .52 40
  msg velocity vectors
  vec x 1
  MSG Press Enter to continue
  pause
  p
  n36
 
 
 
  up z
  msg contours of S at time = 0.90s
  con s1 x 1 sh;.49 .52 40
  msg velocity vectors
  vec x 1
  MSG Press Enter to continue
  pause
  p
  n40
 
 
 
  up z
  msg contours of S at time = 1.0s
  con s1 x 1 sh;.49 .52 40
  msg velocity vectors
  vec x 1
  msg            -
  msg Press e to END
  enduse
 
    GROUP 1. Run title and other preliminaries
text( Slumping of a liquid column by SEM method:146
  FREE SURFACE EXAMPLES - Slumping of a column of liquid
                               Scalar Equation Method (SEM)
 
  2-dimensional (y-z), Cartesian, transient, elliptic simulation


  DISPLAY 
  This case simulates the slumping of a  liquid column that may
  arise, for example, when container walls break down. In
  addition an obstacle can be errected in the path of the liquid.
 
               liquid
            |   column
            |------                   z ^
            | - - |                     |
            |  -  |                     +----->
            | --  |      | wall              y
            |  -- |      |
            |_____|______|___
            /////////////////
 
  The run  shows  that use of PLANT results in compact Q1 coding to
  introduce the basic features of SEM method.  It  should  be  also
  noted  that  upwind convection scheme may not perform well enough
  suffering exessive false diffusion.  The low  dispersion  schemes
  give  significantly  higher  accuracy  in  free  surface location
  calculation.  For more details and comparison with experiment see
  the  entry  SEM  of  PHOENICS  2.0 and older and references cited
  therein. One of them,  namely, of C.W.Hirt and B.D. Nichols in J.
  Comput. Phys., v. 39, 1981, pp.201- , is openly available.

  ENDDIS
 
mesg(Slumping of a clolumn of liquid
 
    GROUP 2. Transience; time-step specification
steady=f;lstep=40
tfrac(1)=-lstep;tfrac(2)= 0.025
    GROUP 4. Y-direction grid specification
grdpwr(y,10,2.0,1.0)
    GROUP 5. Z-direction grid specification
grdpwr(z,10,0.5,1.0)
    GROUP 7. Variables stored, solved & named
solutn(p1,y,y,y,n,n,n)
solutn(v1,y,y,n,n,n,n)
solutn(w1,y,y,n,n,n,n)
  * Free surface marker variable
solve(s1,p1,v1,w1)
 
    GROUP 8. Terms (in differential equations) & devices
  ** activate the "gas-and-liquid algorithm", ie volumetric continui
     equation, and allow convection fluxes to be modified in GROUND
gala=t
terms(s1,n,y,n,y,p,p)
    GROUP 11. Initialization of variable or porosity fields
fiinit( p1 )=0.0;fiinit( v1 )=0.0
fiinit( w1 )=0.0;fiinit(s1)=0.0
iniadd=f
 
  ** place the initial "pile" of liquid of which the slumping is to
     be simulated
patch(liquid,inival,1,nx,1,5,1,5,1,1)
init(liquid,s1,0.0,1.0)
 
    GROUP 13. Boundary conditions and special sources
  ** the pressure is held to zero along the open top boundary
patch(refp,cell,1,nx,1,ny,nz,nz,1,lstep)
coval(refp,p1, fixp , 0.0)
 
  ** provide for the gravity-force source of w1
patch(grav,phasem,1,nx,1,ny,1,nz,1,lstep)
coval(grav,w1,fixflu,-9.81)

  PLANTBEGIN 
  ** Efective pressure gradient sources
PATCH(DPDZ,CELL,1,NX,1,NY,1,NZ,1,lstep)
   VAL=(1.-1./(1000.*S1+(1.-S1)))*AHIGH*(HIGH(P1)-P1)
COVAL(DPDZ,W1,FIXFLU,GRND)
 
PATCH(DPDY,CELL,1,NX,1,NY,1,NZ,1,lstep)
   VAL=(1.-1./(1000.*S1+(1.-S1)))*ANORTH*(NORTH(P1)-P1)
COVAL(DPDY,V1,FIXFLU,GRND)
  PLANTEND

    GROUP 15. Termination of sweeps
lsweep=10;liter(s1)=1
 
    GROUP 16. Termination of iterations
resref(p1)=1.e-6
resref(v1)=1.e-6
resref(w1)=1.e-6
 
    GROUP 17. Under-relaxation devices
relax(v1,falsdt,0.1)
relax(w1,falsdt,0.1)
SPEDAT(SET,GXMONI,TRANSIENT,L,F) 
    GROUP 19. Data communicated by satellite to GROUND
  ** provide for the dumping of field data at each time step, for us
  by PHOTON
  isg2=2
idispa=4;csg1=n
NAMSAT=MOSG
rlolim=0.4;ruplim=0.6
varmin(s1)=0.0; varmax(s1)=1.0
    GROUP 22. Spot-value print-out
iymon=ny/2;izmon=nz/2
 
    GROUP 23. Field print-out and plot control
ntprin=lstep/2
output( p1 ,y,y,y,y,y,y)
output( v1 ,y,y,y,y,y,y)
output( w1 ,y,y,y,y,y,y)
output( s1,y,y,y,y,y,y)

tstswp=-1
dmpstk=t
DISTIL=T
EX(P1)=7.082E+01; EX(V1)=4.885E-01
EX(W1)=1.421E-01; EX(S1)=1.340E-01
 LIBREF=146
STOP