TALK=T;RUN(1,1)
  AUTOPLOT USE
  file
  phi 5

  da 1
  1u
  screen
  msg 1st-phase (gas) velocity at t=1s
  pl 1
  msg press  to continue
  pause
  cl
  da 1
  2u
  screen
  msg 2nd-phase (liquid) velocity at t=1s
  pl 1
  msg press  to continue
  pause
  cl
  da 1
  gas
  screen
  msg 1st-phase (gas) volume fraction at t=1s
  pl 1
  msg press  to continue
  pause
  cl
  da 1
  liq
  screen
  msg 2nd-phase (liquid) volume fraction at t=1s
  pl 1
  msg press  to continue
  pause
  cl
  da 1
  p1
  screen
  msg pressure at t=1s
  pl 1
  msg press e to END
  enduse
  DISPLAY
    NUMERICAL BENCHMARK PROBLEM 2.7: STRATIFIED FLOW
    A horizontal duct is divided into two equal-length parts
    by a diaphragm, each of which contains both water and air,
    the former lying below the latter. The depth of the water
    is somewhat greater on the left of the diaphragm than it
    is on the right.

    The diaphragm is supposed suddenly to break; the task is
    then to calculate what happens during the next few
    seconds, during which the water and air are set in
    motion, in opposite direction, as gravity waves travel
    from the diaphragm-rupture point towards the two ends.

    Two cases are to be considered, differing in respect of
    the postulated cross-section of the duct. In case 1 it
    is square, whereas in case 2 it is circular.
      _________________________________________________
      i                        :--->diaphragm          i
      i                        :                       i
      i------------------------:                       i
      i =    =   =   =  =  =   :                       i
      i   =    =   =   =       :-----------------------i
      i =   =    water    =    :      air              i
      i   =  =    =     =    = :                       i
      _________________________________________________
      |                        |                       |
      |<------- 5 m ---------->|                       |
      |<---------------- 10 m ------------------------>|
  ENDDIS
 ************************************************************
  Group 1. Run Title and Number
 ************************************************************
 ************************************************************
 
 TEXT(STRATIFIED FLOW, CASE 1 CHANNEL :   W900)
 
 ************************************************************
 ************************************************************
 
 IRUNN = 1 ;LIBREF = 14
 ************************************************************
  Group 2. Time dependence
 STEADY = F
    * Set overall time and no. of steps
 TFIRST =0. ;TLAST =1.
 FSTEP = 1 ;LSTEP = 100
   Method of pairs used for grid setting.
 TFRAC(2)=1.0E-02
 ************************************************************
  Group 3. X-Direction Grid Spacing
 CARTES = T
 NX = 100
 XULAST =10.
 XFRAC(1)=1.0E-02 ;XFRAC(6)=0.06
 XFRAC(11)=0.11 ;XFRAC(16)=0.16
 XFRAC(21)=0.21 ;XFRAC(26)=0.26
 XFRAC(31)=0.31 ;XFRAC(36)=0.36
 XFRAC(41)=0.41 ;XFRAC(46)=0.46
 XFRAC(51)=0.51 ;XFRAC(56)=0.56
 XFRAC(61)=0.61 ;XFRAC(66)=0.66
 XFRAC(71)=0.71 ;XFRAC(76)=0.76
 XFRAC(81)=0.81 ;XFRAC(86)=0.86
 XFRAC(91)=0.91 ;XFRAC(96)=0.96
 ************************************************************
  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)=1U
 NAME(4)=2U ;NAME(9)=GAS
 NAME(10)=LIQ
    * 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(1U,Y,Y,N,N,N,Y)
 SOLUTN(2U,Y,Y,N,N,N,Y)
 SOLUTN(GAS,Y,Y,N,N,N,Y)
 SOLUTN(LIQ,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(1U,Y,Y,N,Y,Y,Y)
 TERMS(2U,Y,Y,N,Y,N,Y)
 TERMS(GAS,Y,Y,N,Y,Y,Y)
 TERMS(LIQ,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 =1000. ;TMP2 =0.
 EL2 =0.
 DVO2DT =0. ;DRH2DP =0.
 ENUL =1.0E-05 ;ENUT =0.
 PHINT(1U)=-2.022E+04 ;PHINT(2U)=-2.022E+04
 PHINT(GAS)=-2.022E+04 ;PHINT(LIQ)=-2.022E+04
 CP1 =1. ;CP2 =1.
 ************************************************************
  Group 10.Inter-Phase Transfer Processes
 CFIPS =0.
 ************************************************************
  Group 11.Initial field variables (PHIs)
 FIINIT(P1)=1.0E-10 ;FIINIT(1U)=0.
 FIINIT(2U)=0. ;FIINIT(GAS)=0.49
 FIINIT(LIQ)=0.51
 
 PATCH(START ,INIVAL, 51, 100, 1, 1, 1, 1, 1, 1)
 INIT(START ,GAS ,0. ,0.02 )
 INIT(START ,LIQ ,0. ,-0.02 )
 INIADD = T
 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 , 50, 50, 1, 1, 1, 1, 1, 100)
 COVAL(RELIEF ,GAS ,1. ,0. )
 
 PATCH(LATG ,RGRAD , 1, 100, 1, 1, 1, 1, 1, 100)
 COVAL(LATG ,2U ,0. ,9800.19043 )
 XCYCLE = F
 EGWF = T
 WALLCO = GRND2
 ************************************************************
  Group 14. Downstream Pressure For PARAB
 ************************************************************
  Group 15. Terminate Sweeps
 LSWEEP = 30 ;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(1U)=10
 LITER(2U)=10 ;LITER(GAS)=1
 LITER(LIQ)=1
 ENDIT(P1)=1.0E-03 ;ENDIT(1U)=1.0E-03
 ENDIT(2U)=1.0E-03 ;ENDIT(GAS)=1.0E-03
 ENDIT(LIQ)=1.0E-03
 ************************************************************
  Group 17. Relaxation
 RELAX(P1,LINRLX,1.)
 RELAX(1U,FALSDT,1.0E-02)
 RELAX(2U,FALSDT,1.0E-02)
 RELAX(GAS,LINRLX,0.3)
 RELAX(LIQ,LINRLX,0.3)
 OVRRLX =0.
 EXPERT = F ;NNORSL = F
 ************************************************************
  Group 18. Limits
 VARMAX(P1)=1.0E+10 ;VARMIN(P1)=-1.0E+10
 VARMAX(1U)=1.0E+06 ;VARMIN(1U)=-1.0E+06
 VARMAX(2U)=1.0E+06 ;VARMIN(2U)=-1.0E+06
 VARMAX(GAS)=1. ;VARMIN(GAS)=1.0E-06
 VARMAX(LIQ)=1. ;VARMIN(LIQ)=1.0E-06
 ************************************************************
  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(1U,Y,N,Y,Y,Y,Y)
 OUTPUT(2U,Y,N,Y,Y,Y,Y)
 OUTPUT(GAS,Y,N,Y,Y,Y,Y)
 OUTPUT(LIQ,Y,N,Y,Y,Y,Y)
 ************************************************************
  Group 22. Monitor Print-Out
 IXMON = 51 ;IYMON = 1 ;IZMON = 1
 NPRMON = 100000 ;NPRMNT = 1 ;TSTSWP = -1
 UWATCH = T ;USTEER = T
 HIGHLO = F
 ************************************************************
  Group 23.Field Print-Out & Plot Control
 NPRINT = 100000 ;NUMCLS = 5
 NTPRIN = 50 ;ISTPRF = 1 ;ISTPRL = 100000
 NXPRIN = 5 ;IXPRF = 1 ;IXPRL = 10000
 IPLTF = 1 ;IPLTL = 30 ;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(LONGPLOT,PROFIL, 1, 100, 1, 1, 1, 1, 1, 100)
 PLOT(LONGPLOT,1U ,-1. ,-1. )
 PLOT(LONGPLOT,2U ,-1. ,-1. )
 PLOT(LONGPLOT,LIQ ,0. ,0. )
 
 PATCH(TIMEPLOT,PROFIL, 25, 25, 1, 1, 1, 1, 1, 100)
 PLOT(TIMEPLOT,1U ,-1. ,-1. )
 PLOT(TIMEPLOT,2U ,-1. ,-1. )
 PLOT(TIMEPLOT,LIQ ,0. ,0. )
 ************************************************************
  Group 24. Dumps For Restarts
 SAVE = T ;NOWIPE = F
 NSAVE =CHAM
STOP