TALK=T;RUN(1,1)
  photon use
  p;parphi;;;;;

  mesg horizontal direction (z) represents time
  gr y 1

  msg first-phase volume-fraction contours
  con r1 y 1 fi;0.05;pause
  msg first-phase velocity contours
  con u1 y 1 fi;0.05;pause
  msg pressure contours
  con p1 y 1 fi;0.05
  enduse
  DISPLAY

  The initial condition is that two fluids of equal density are
  moving at equal but opposite velocity within a duct of uniform
  cross-section; and each has a volume fraction of 0.5.

  Because the ends of the duct are closed, each fluid tends to
  accumulate at the end towards which it is moving.

  Fluid-to-fluid and fluid-to-wall friction are neglected. One
  consequence is the growth of an instability in the interface,
  exhibited by a reduction in the volume fraction of each fluid
  just ahead of the point at which it rises to unity.

  Instabilities of Kelvin-Helmholtz type are known to arise in
  such flows; but the one just mentioned is more likely to be a
  consequence of the fact that no provision has been made for the
  enhanced fluid-to-fluid momentum transfer which occurs at an
  abrupt chnage of vulume fraction, which is akin to a 'hydraulic
  jump'.

  A PHOTON USE file is provided for display purposes.

  ENDDIS
 ************************************************************
  Group 1. Run Title and Number
 ************************************************************
 ************************************************************
 
 TEXT(fluids moving in opposite directions:423)
 
 ************************************************************
 ************************************************************
 
 IRUNN = 1 ;LIBREF = 14
 ************************************************************
  Group 2. Time dependence
 STEADY = F
    * Set overall time and no. of steps
 TFIRST =0. ;TLAST =1.5
 FSTEP = 1 ;LSTEP = 60
 TFRAC(1)=0.016667 ;TFRAC(2)=0.033333
 TFRAC(3)=0.05 ;TFRAC(4)=0.066667
 TFRAC(5)=0.083333 ;TFRAC(6)=0.1
 TFRAC(7)=0.116667 ;TFRAC(8)=0.133333
 TFRAC(9)=0.15 ;TFRAC(10)=0.166667
 TFRAC(11)=0.183333 ;TFRAC(12)=0.2
 TFRAC(13)=0.216667 ;TFRAC(14)=0.233333
 TFRAC(15)=0.25 ;TFRAC(16)=0.266667
 TFRAC(17)=0.283333 ;TFRAC(18)=0.3
 TFRAC(19)=0.316667 ;TFRAC(20)=0.333333
 TFRAC(21)=0.35 ;TFRAC(22)=0.366667
 TFRAC(23)=0.383333 ;TFRAC(24)=0.4
 TFRAC(25)=0.416667 ;TFRAC(26)=0.433333
 TFRAC(27)=0.45 ;TFRAC(28)=0.466667
 TFRAC(29)=0.483333 ;TFRAC(30)=0.5
 TFRAC(31)=0.516667 ;TFRAC(32)=0.533333
 TFRAC(33)=0.55 ;TFRAC(34)=0.566667
 TFRAC(35)=0.583333 ;TFRAC(36)=0.6
 TFRAC(37)=0.616667 ;TFRAC(38)=0.633333
 TFRAC(39)=0.65 ;TFRAC(40)=0.666667
 TFRAC(41)=0.683333 ;TFRAC(42)=0.7
 TFRAC(43)=0.716667 ;TFRAC(44)=0.733333
 TFRAC(45)=0.75 ;TFRAC(46)=0.766667
 TFRAC(47)=0.783333 ;TFRAC(48)=0.8
 TFRAC(49)=0.816667 ;TFRAC(50)=0.833333
 TFRAC(51)=0.85 ;TFRAC(52)=0.866667
 TFRAC(53)=0.883333 ;TFRAC(54)=0.9
 TFRAC(55)=0.916667 ;TFRAC(56)=0.933333
 TFRAC(57)=0.95 ;TFRAC(58)=0.966667
 TFRAC(59)=0.983333 ;TFRAC(60)=1.
 ************************************************************
  Group 3. X-Direction Grid Spacing
 CARTES = T
 NX = 30
 XULAST =0.5
 XFRAC(1)=0.033333 ;XFRAC(2)=0.066667
 XFRAC(3)=0.1 ;XFRAC(4)=0.133333
 XFRAC(5)=0.166667 ;XFRAC(6)=0.2
 XFRAC(7)=0.233333 ;XFRAC(8)=0.266667
 XFRAC(9)=0.3 ;XFRAC(10)=0.333333
 XFRAC(11)=0.366667 ;XFRAC(12)=0.4
 XFRAC(13)=0.433333 ;XFRAC(14)=0.466667
 XFRAC(15)=0.5 ;XFRAC(16)=0.533333
 XFRAC(17)=0.566667 ;XFRAC(18)=0.6
 XFRAC(19)=0.633333 ;XFRAC(20)=0.666667
 XFRAC(21)=0.7 ;XFRAC(22)=0.733333
 XFRAC(23)=0.766667 ;XFRAC(24)=0.8
 XFRAC(25)=0.833333 ;XFRAC(26)=0.866667
 XFRAC(27)=0.9 ;XFRAC(28)=0.933333
 XFRAC(29)=0.966667 ;XFRAC(30)=1.
 ************************************************************
  Group 4. Y-Direction Grid Spacing
 NY = 1
 YVLAST =1.
 YFRAC(1)=1.
 ************************************************************
  Group 5. Z-Direction Grid Spacing
 PARAB = F
 NZ = 1
 ZWLAST =1.
 ZFRAC(1)=1.
 ************************************************************
  Group 6. Body-Fitted Coordinates
 ************************************************************
  Group 7. Variables: STOREd,SOLVEd,NAMEd
 ONEPHS = F
 EQUVEL = F
 NAME(1)=P1 ;NAME(3)=U1
 NAME(4)=U2 ;NAME(9)=R1
 NAME(10)=R2
    * Y in SOLUTN argument list denotes:
    * 1-stored 2-solved 3-whole-field
    * 4-point-by-point 5-explicit 6-harmonic averaging 
 SOLUTN(P1,Y,Y,N,N,N,Y)
 SOLUTN(U1,Y,Y,N,N,N,Y)
 SOLUTN(U2,Y,Y,N,N,N,Y)
 SOLUTN(R1,Y,Y,N,N,N,Y)
 SOLUTN(R2,Y,Y,N,N,N,Y)
 ************************************************************
  Group 8. Terms & Devices
    * Y in TERMS argument list denotes:
    * 1-built-in source 2-convection 3-diffusion 4-transient
    * 5-first phase variable 6-interphase transport         
 TERMS(P1,Y,Y,Y,N,Y,Y)
 TERMS(U1,Y,Y,Y,Y,Y,Y)
 TERMS(U2,Y,Y,Y,Y,N,Y)
 TERMS(R1,Y,Y,N,Y,Y,Y)
 TERMS(R2,Y,Y,N,Y,N,Y)
 DIFCUT =0.5 ;ZDIFAC =1.
 GALA = F ;ADDDIF = F
 EQDVDP = F
 ISOLX = -1 ;ISOLY = -1 ;ISOLZ = -1
 ************************************************************
  Group 9. Properties used if PRPS is not
  stored, and where PRPS = -1.0 if it is!
 RHO1 =1. ;TMP1 =0.
 EL1 =0.
 TSURR =0. ;TEMP0 =0.
 PRESS0 =0.
 DVO1DT =0. ;DRH1DP =0.
 EMISS =0. ;SCATT =0.
 RADIA =0. ;RADIB =0.
 RHO2 =1. ;TMP2 =0.
 EL2 =0.
 DVO2DT =0. ;DRH2DP =0.
 ENUL =0. ;ENUT =0.
 PHINT(U1)=-2.022E+04 ;PHINT(U2)=-2.022E+04
 PHINT(R1)=-2.022E+04 ;PHINT(R2)=-2.022E+04
 PRNDTL(U1)=1. ;PRNDTL(U2)=1.
 PRT(U1)=1. ;PRT(U2)=1.
 CP1 =1. ;CP2 =1.
 ************************************************************
  Group 10.Inter-Phase Transfer Processes
 CFIPS =0.
 ************************************************************
  Group 11.Initial field variables (PHIs)
 FIINIT(P1)=1.0E-10 ;FIINIT(U1)=0.1
 FIINIT(U2)=-0.1 ;FIINIT(R1)=0.5
 FIINIT(R2)=0.5
   No PATCHes yet used for this Group
 INIADD = F
 FSWEEP = 1
 NAMFI =CHAM
 ************************************************************
  Group 12. Patchwise adjustment of terms
  Patches for this group are printed with those
  for Group 13.
  Their names begin either with GP12 or &
 ************************************************************
  Group 13. Boundary & Special Sources
 
 PATCH(RELIEF ,CELL , 15, 15, 1, 1, 1, 1, 1, 60)
 COVAL(RELIEF ,U1 ,0. ,0. )
 COVAL(RELIEF ,R1 ,1. ,0. )
 XCYCLE = F
 EGWF = T
 WALLCO = GRND2
 ************************************************************
  Group 14. Downstream Pressure For PARAB
 ************************************************************
  Group 15. Terminate Sweeps
 LSWEEP = 20 ;ISWC1 = 1
 LITHYD = 1 ;LITFLX = 1 ;LITC = 1 ;ITHC1 = 1
 ISWR1 = 1 ;ISWR2 = 10000
 SELREF = T
 RESFAC =1.0E-04
 ************************************************************
  Group 16. Terminate Iterations
 LITER(P1)=20 ;LITER(U1)=10
 LITER(U2)=10 ;LITER(R1)=1
 LITER(R2)=1
 ENDIT(P1)=1.0E-03 ;ENDIT(U1)=1.0E-03
 ENDIT(U2)=1.0E-03 ;ENDIT(R1)=1.0E-03
 ENDIT(R2)=1.0E-03
 ************************************************************
  Group 17. Relaxation
 RELAX(P1,LINRLX,1.)
 RELAX(U1,FALSDT,1.)
 RELAX(U2,FALSDT,1.)
 RELAX(R1,LINRLX,0.4)
 RELAX(R2,LINRLX,0.4)
 OVRRLX =0.
 EXPERT = F ;NNORSL = F
 ************************************************************
  Group 18. Limits
 VARMAX(P1)=1.0E+10 ;VARMIN(P1)=-1.0E+10
 VARMAX(U1)=1.0E+06 ;VARMIN(U1)=-1.0E+06
 VARMAX(U2)=1.0E+06 ;VARMIN(U2)=-1.0E+06
 VARMAX(R1)=1. ;VARMIN(R1)=1.0E-10
 VARMAX(R2)=1. ;VARMIN(R2)=1.0E-10
 ************************************************************
  Group 19. Data transmitted to GROUND
 PARSOL = F
 ISG62 = 1
 SPEDAT(SET,GXMONI,TRANSIENT,L,F)
 ************************************************************
  Group 20. Preliminary Printout
 ************************************************************
  Group 21. Print-out of Variables
 INIFLD = F ;SUBWGR = F
    * Y in OUTPUT argument list denotes:
    * 1-field 2-correction-eq. monitor 3-selective dumping      
    * 4-whole-field residual 5-spot-value table 6-residual table
 OUTPUT(P1,Y,N,Y,Y,Y,Y)
 OUTPUT(U1,Y,N,Y,Y,Y,Y)
 OUTPUT(U2,Y,N,Y,Y,Y,Y)
 OUTPUT(R1,Y,Y,Y,Y,Y,Y)
 OUTPUT(R2,Y,Y,Y,Y,Y,Y)
 ************************************************************
  Group 22. Monitor Print-Out
 IXMON = 1 ;IYMON = 1 ;IZMON = 1
 NPRMON = 100000 ;NPRMNT = 1 ;TSTSWP = 19
 UWATCH = T ;USTEER = T
 HIGHLO = F
 ************************************************************
  Group 23.Field Print-Out & Plot Control
 NPRINT = 100000 ;NUMCLS = 5
 NTPRIN = 100000 ;ISTPRF = 1 ;ISTPRL = 100000
 NXPRIN = -1 ;IXPRF = 1 ;IXPRL = 10000
 IPLTF = 1 ;IPLTL = -1 ;NPLT = -1
 ISWPRF = 1 ;ISWPRL = 100000
 ITABL = 1 ;IPROF = 1
 ABSIZ =0.5 ;ORSIZ =0.4
 NTZPRF = 1 ;NCOLPF = 50
 ICHR = 2 ;NCOLCO = 45 ;NROWCO = 20
 
 PATCH(IXPLOT ,PROFIL, 1, 30, 1, 1, 1, 1, 1, 60)
 PLOT(IXPLOT ,R1 ,0. ,1. )
 ************************************************************
  Group 24. Dumps For Restarts
 SAVE = T ;NOWIPE = F
 NSAVE =CHAM
 IDISPA = 4 ;IDISPB = 0 ;IDISPC = 0
STOP