photon use
  p
  parphi
  1 1500 1500
 
 
  msg contours of reactedness. Distance is vertical, time horizontal
  con rctd y 1 fi;0.1
  enduse
  ** L(109) from the PHOENICS Input Library
     ****** TO LOAD CASE: TYPE L(109) ******
       GROUP 1. Run title and other preliminaries
TEXT(1D Trans Laminar Flame Propagation
TITLE
  DISPLAY
    This case represents the main features of transient plane
    laminar flame propagation through a combustible mixture. The
    reaction rate is proportional to (1-r)*r**n, where
    r = reactedness, a "progress variable" which changes from 0.0
    to 1.0 as reaction proceeds, while n is a constant exponent.
    The distance variable x represents:
                                    integral(density * d distance).
 
    In the example provided, the flame propagates from the high-x
    end to the low-x end.
 
    It should be found that the speed of propagation is proportional
    to the square root of the product of the transport coefficient
    (ENUL) and the reaction-rate constant (CHSOA).
 
    -----------------------------------------------------
    r=1.e-4        <--| flame-front                    r=1.
    -----------------------------------------------------
                          x----->
  ENDDIS
 
    GROUP 2. Transience; time-step specification
STEADY=F;GRDPWR(T,50,1.0E-3,1.0)
    GROUP 3. X-direction grid specification
GRDPWR(X,50,1.0,1.0)
    GROUP 7. Variables stored, solved & named
SOLVE(RCTD)
    GROUP 8. Terms (in differential equations) & devices
  ** Convection is set to zero, which implies that the
TERMS(RCTD,Y,N,Y,Y,Y,Y)
    GROUP 9. Properties of the medium (or media)
enul=100.0
mesg(The dimensionless diffusion time dx**2/(enul*dt) equals
mesg(:(xulast/nx)**2/(enul*tlast/lstep):
    GROUP 11. Initialization of variable or porosity fields
FIINIT(RCTD)=0.0
    GROUP 13. Boundary conditions and special sources
   ** RCTD is held to unity at IX=NX
PATCH(IXEQNX,CELL,NX,NX,1,1,1,1,1,LSTEP)
COVAL(IXEQNX,RCTD,FIXVAL,1.0)
   ** A non-linear source of RCTD is present; for this
      purpose, the subroutine GXCHSO is called from GREX3,
      group13 by setting COefficient to POLYNOM (GRND7) in the COVAL
      command; the subroutine is entered only when the patch
      name begins with the character CHSO.
      CO=POLYNOM (GRND7) selects the following option:
      COefficient=CHSOA*RCTD**CHSOB
PATCH(CHSOTERM,VOLUME,1,NX,1,1,1,1,1,LSTEP)
COVAL(CHSOTERM,RCTD,POLYNOM,1.0)
CHSOA=1.0E5;CHSOB=6.0
    GROUP 15. Termination of sweeps
LSWEEP=10
 
    GROUP 22. Spot-value print-out
TSTSWP=LSWEEP/4
SPEDAT(SET,GXMONI,TRANSIENT,L,F)
    GROUP 23. Field print-out and plot control
NXPRIN=NX/5;NTPRIN=LSTEP/4;NPLT=1
   ** Plot profiles over the length of the domain
PATCH(XWISE,PROFIL,1,NX,1,1,1,1,1,LSTEP)
PLOT(XWISE,RCTD,0.0,0.0)
   ** Plot a profile of the values at IX=3*NX/4
      with time as the abscissa
PATCH(TIMEWISE,PROFIL,NX/2,3*NX/4,1,1,1,1,1,LSTEP)
PLOT(TIMEWISE,RCTD,0.0,0.0)
ixmon=nx/2;IDISPA=1;UWATCH=T