AUTOPLOT USE
  file
  phi 5
 
  da 1
  au1
  screen
  msg gas velocity
  pl 1
  msg press  to continue
  pause
  cl
  da 1
  bu2
  screen
  msg liquid velocity
  pl 1
  msg press  to continue
  pause
  cl
  da 1
  gas
  screen
  msg gas volume fraction
  pl 1
  msg press  to continue
  pause
  cl
  da 1
  shad
  screen
  msg 'shadow' volume fraction of denser phase
  pl 1
  msg press  to continue
  pause
  cl
  da 1
  p1
  screen
  msg pressure
  pl 1
  msg press e to END
  enduse
    GROUP 1. Run title
TEXT(MONOPROPELLANT ROCKET :             W570
TITLE
  DISPLAY
  The problem considered is that of the injection of monopropellant
  droplets through small holes in one end of a rocket motor. These
  droplets burn (i.e undergo a phase change involving the dis-
  appearance of high-density liquid and its replacement by low-
  density gas), at a rate dependent upon the droplet diameter. As a
  consequence, a pressure gradient is set up which accelerates the
  gas and, to a lesser extent, the liquid. Friction between the
  droplets and the gas causes the former at first to deccelerate
  and later a accelerate.
 
  The main task is to compute the distance from the injector at
  which the propellant is fully consumed, as functions: of the
  injection velocity, of the propellant and combustion-product
  properties, and of a measure of the relative speed of momentum
  and heat transfer.
  ENDDIS
  The GX-subroutine GXDROP is used for this case.
      Locally-defined parameters:
      FLOW       mass flow rate at the inlet
      VELIN      inlet velocity
      XLEN       the length of the rocket motor
      CHATIM     relaxation factor
REAL(FLOW,VELIN,XLEN,CHATIM);FLOW=1.E3;VELIN=50.0;XLEN=1.0
CHATIM=XLEN/VELIN
    GROUP 3. X-direction grid specification
GRDPWR(X,100,XLEN,1.0)
    GROUP 7. Variables stored, solved & named
ONEPHS=F;SOLVE(P1,U1,U2,R1,R2,RS)
NAME(U1)=AU1;NAME(U2)=BU2;NAME(R1)=GAS;NAME(R2)=LIQ;NAME(RS)=SHAD
SOLUTN(GAS,Y,N,N,N,N,N)
TERMS(GAS,Y,Y,N,Y,Y,Y);TERMS(LIQ,Y,Y,N,Y,N,Y)
TERMS(SHAD,Y,Y,N,Y,N,Y);TERMS(AU1,Y,Y,N,Y,Y,Y)
TERMS(BU2,Y,Y,N,Y,N,Y)
    GROUP 9. Properties of the medium (or media)
RHO1=1.E1;RHO2=1.E4;PRESS0=1.E7
    GROUP 10. Inter-phase-transfer processes and properties
    Set the particle size to 0.1mm  and activate the
    calculation of the inter-phase mass transfer by
CFIPS=GRND7;STORE(SIZE);CFIPA=1.0;CFIPB=1E-4;CFIPC=0
CMDOT=GRND1;CMDTA=1/FIINIT(LIQ)
    GROUP 11. Initialization of variable or porosity fields
FIINIT(GAS)=0.999;FIINIT(LIQ)=0.001;FIINIT(SHAD)=0.001
FIINIT(AU1)=VELIN;FIINIT(BU2)=VELIN
    GROUP 13. Boundary conditions and special sources
    Inlet at west end
INLET(INLET,WEST,1,1,1,1,1,1,1,1)
VALUE(INLET,P2,FLOW);VALUE(INLET,BU2,VELIN)
    Outlet at east end
PATCH(OUTLET,CELL,NX,NX,1,1,1,1,1,1)
COVAL(OUTLET,P1,FIXP,0.0);COVAL(OUTLET,P2,FIXP*RHO2/RHO1,0.0)
COVAL(OUTLET,AU1,ONLYMS,0.0);COVAL(OUTLET,BU2,ONLYMS,0.0)
    GROUP 15. Termination of sweeps
LSWEEP=250
    GROUP 16. Termination of iterations
RESREF(P1)=1.E-8*FLOW/RHO1
RESREF(GAS)=RESREF(P1)*RHO1;RESREF(LIQ)=RESREF(P1)*RHO1
RESREF(SHAD)=RESREF(P1)*RHO2*0.1
RESREF(AU1)=RESREF(GAS)*VELIN*1.E-3
RESREF(BU2)=RESREF(LIQ)*VELIN*1.E-3
    GROUP 17. Under-relaxation devices
RELAX(SHAD,LINRLX,0.6);RELAX(LIQ,LINRLX,0.6)
RELAX(AU1,FALSDT,CHATIM);RELAX(BU2,FALSDT,CHATIM)
    GROUP 21. Print-out of variables
OUTPUT(GAS,N,N,N,N,N,N)
    GROUP 22. Spot-value print-out
IXMON=NX*3/4
    GROUP 23. Field print-out and plot control
NPLT=1;ORSIZ=0.4;TSTSWP=-1
PATCH(XPROFILE,PROFIL,1,NX,1,1,1,1,1,1)
PLOT(XPROFILE,SHAD,0.0,0.0);PLOT(XPROFILE,LIQ,0.0,0.0)
PLOT(XPROFILE,AU1,-1.0,-1.0);PLOT(XPROFILE,BU2,-1.0,-1.0)
    GROUP 24. Dumps for restarts