AUTOPLOT USE
  file
  phi 5
 
  da 1
  au1
  screen
  msg 1st-phase (gas) velocity at t=50s
  pl 1
  msg press  to continue
  pause
  cl
  da 1
  bu2
  screen
  msg 2nd-phase (liquid) velocity at t=50s
  pl 1
  msg press  to continue
  pause
  cl
  da 1
  gas
  screen
  msg 1st-phase (gas) volume fraction at t=50s
  pl 1
  msg press  to continue
  pause
  cl
  da 1
  liq
  screen
  msg 2nd-phase (liquid) volume fraction at t=50s
  pl 1
  msg press  to continue
  pause
  cl
  da 1
  p1
  screen
  msg pressure at t=50s
  pl 1
  msg press e to END
  enduse
 
    GROUP 1. Run title and other preliminaries
TEXT(1D TRANSIENT PIPE FILLING :         W425
TITLE
  DISPLAY
  Water enters the base of an air-filled pipe at a steady
  rate, finally filling it.
 
  Numerical diffusion causes the interface to become diffuse,
  to some extent; but the tendency is diminished by the
  activation of the "donor-acceptor" option, set by DONACC=T.
  This may be confirmed by setting DONACC=F and re-running.
 
  Also relevant, and to be experimented with, are the settings
  of the upper- and lower-limit volume-fraction limits at which
  upwind rather than downwind values are employed in the
  balance equations. These are RUPLIM and RLOLIM. See group 8.
  ENDDIS
    GROUP 2. Transience; time-step specification
STEADY=F;GRDPWR(T,10,50.0,1.0)
    GROUP 3. X-direction grid specification
GRDPWR(X,10,1.0,1.0)
    GROUP 7. Variables stored, solved & named
ONEPHS=F;SOLVE(P1,U1,U2,R1,R2)
NAME(U1)=AU1;NAME(U2)=BU2;NAME(R1)=GAS;NAME(R2)=LIQ
    GROUP 8. Terms (in differential equations) & devices
RHO2=1.E3;RLOLIM=0.1;RUPLIM=1.0-RLOLIM;DONACC=T
    GROUP 9. Properties of the medium (or media)
ENUL=1.E-3
    GROUP 10. Inter-phase-transfer processes and properties
  ** Set a constant inter-phase friction coefficient.
CFIPS=1.E4
    GROUP 11. Initialization of variable or porosity fields
FIINIT(GAS)=0.99999;FIINIT(LIQ)=1.E-6;FIINIT(P1)=0.0
FIINIT(AU1)=0.;FIINIT(BU2)=0.
    GROUP 13. Boundary conditions and special sources
  ** Pressure relief
PATCH(REFP,CELL,NX,NX,1,1,1,1,1,LSTEP);COVAL(REFP,P1,FIXP,0.0)
  ** INLET
PATCH(INLET,WEST,1,1,1,1,1,1,1,LSTEP)
COVAL(INLET,P2,FIXFLU,RHO2*0.01)
  ** Gravity
PATCH(GRAVITY,PHASEM,1,NX,1,1,1,1,1,LSTEP)
COVAL(GRAVITY,AU1,FIXFLU,-9.81);COVAL(GRAVITY,BU2,FIXFLU,-9.81)
    GROUP 15. Termination of sweeps
LSWEEP=40;RESREF(P1)=1.E-8;RESREF(GAS)=1.E-5;RESREF(LIQ)=1.E-5
    GROUP 17. Under-relaxation devices
RELAX(GAS,LINRLX,1.0);RELAX(LIQ,LINRLX,1.0)
RELAX(AU1,FALSDT,0.01);RELAX(BU2,FALSDT,0.01)
    GROUP 19. Data communicated by satellite to GROUND
USEGRD=F;USEGRX=F
SPEDAT(SET,GXMONI,TRANSIENT,L,F)
    GROUP 21. Print-out of variables
OUTPUT(GAS,N,N,N,N,N,N)
    GROUP 22. Spot-value print-out
IXMON=1;TSTSWP=-1
    GROUP 23. Field print-out and plot control
NTPRIN=LSTEP;ITABL=1;IPLTL=100
PATCH(ALLX,PROFIL,1,NX,1,1,1,1,1,LSTEP)
PLOT(ALLX,LIQ,0.0,1.0);PLOT(ALLX,P1,0.0,0.0)
PATCH(LONGPLOT,PROFIL,1,1,1,1,1,1,1,LSTEP)
PLOT(LONGPLOT,LIQ,0.0,1.0);PLOT(LONGPLOT,P1,0.0,0.0)