TALK=T;RUN(1,1)
  DISPLAY
    Radiative heat transfer takes place between parallel flat
    wide surfaces. The medium between them is at rest, and can
    absorb, emit and scatter radiation, as well as conducting
    heat.

    Wall temperatures and emissivities are prescribed.

    The RADIAT command is used to activate the radiation model of
    subroutine GXRADI.

    The solved-for variables are enthalpy, H1, and the composite
    radiation flux, RADX, defined as the arithmetic mean of the
    radiation fluxes in the +X and -X directions.

    RADX has a diffusivity which depends on the scattering and
    absorption coefficients.

    Press RETURN to continue
    The wall boundary condition for RADX has a Value equal to the
    gross radiation flux emitted by the wall; thus the net flux is
    proportional to:
       sigma*Tw**4 - RADX
    The COefficient for RADX is a function of emissivity.
    The locally-defined parameters are as follows:
               GSIGMA         Stefan-Boltzmann constant
               SCAT           Scattering coefficient
               ABSORB         Absorption coefficient
               EMIH           emissivity of the hot wall
               EMIC           emissivity of the cold wall
               THOT           hot wall temperature
               TCOLD          cold wall temperature
  ENDDIS
 ************************************************************
  Group 1. Run Title and Number
 ************************************************************
 ************************************************************
 
 TEXT(1D Radiant Heat Transfre In A Box       )
 
 ************************************************************
 ************************************************************
 
 IRUNN = 1 ;LIBREF = 14
 ************************************************************
  Group 2. Time dependence
 STEADY = T
 ************************************************************
  Group 3. X-Direction Grid Spacing
 CARTES = T
 NX = 20
 XULAST =1.
 XFRAC(1)=0.015811 ;XFRAC(2)=0.044721
 XFRAC(3)=0.082158 ;XFRAC(4)=0.126491
 XFRAC(5)=0.176777 ;XFRAC(6)=0.232379
 XFRAC(7)=0.292831 ;XFRAC(8)=0.357771
 XFRAC(9)=0.426907 ;XFRAC(10)=0.5
 XFRAC(11)=0.573092 ;XFRAC(12)=0.642229
 XFRAC(13)=0.707169 ;XFRAC(14)=0.767621
 XFRAC(15)=0.823223 ;XFRAC(16)=0.873509
 XFRAC(17)=0.917842 ;XFRAC(18)=0.955279
 XFRAC(19)=0.984189 ;XFRAC(20)=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 = T
 NAME(14)=H1 ;NAME(150)=RADX
    * Y in SOLUTN argument list denotes:
    * 1-stored 2-solved 3-whole-field
    * 4-point-by-point 5-explicit 6-harmonic averaging 
 SOLUTN(H1,Y,Y,N,N,N,Y)
 SOLUTN(RADX,Y,Y,N,N,N,N)
 ************************************************************
  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(H1,N,N,Y,Y,Y,Y)
 TERMS(RADX,N,N,Y,N,Y,N)
 DIFCUT =0.5 ;ZDIFAC =1.
 GALA = F ;ADDDIF = 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 = GRND2
 EL1 =0.
 TSURR =0. ;TEMP0 =0.
 PRESS0 =0.
 DVO1DT =0. ;DRH1DP =0.
 TMP1A =0. ;TMP1B =1.
 TMP1C =0.
 TMP2A =0. ;TMP2B =0.
 TMP2C =0.
 EMISS =0. ;SCATT =0.
 RADIA =0.2 ;RADIB =0.05
 ENUL =1.0E-03 ;ENUT =0.
 PRNDTL(H1)=0.7 ;PRNDTL(RADX)=-GRND1
 PRT(H1)=1. ;PRT(RADX)=1.0E+10
 CP1 =1. ;CP2 =1.
 ************************************************************
  Group 10.Inter-Phase Transfer Processes
 ************************************************************
  Group 11.Initial field variables (PHIs)
 FIINIT(H1)=450. ;FIINIT(RADX)=2324.931396
   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(RADISO ,FREEVL, 0, 0, 0, 0, 0, 0, 1, 1)
 COVAL(RADISO ,H1 , GRND1 , GRND1 )
 COVAL(RADISO ,RADX, GRND1 , GRND1 )
 
 PATCH(WESTR ,WEST , 1, 1, 1, 1, 1, 1, 1, 1)
 COVAL(WESTR ,RADX,0.333333 ,7347.931152 )
 
 PATCH(EASTR ,EAST , 20, 20, 1, 1, 1, 1, 1, 1)
 COVAL(EASTR ,RADX,0.111111 ,459.245697 )
 
 PATCH(WESTH ,WWALL , 1, 1, 1, 1, 1, 1, 1, 1)
 COVAL(WESTH ,H1 ,1. ,600. )
 
 PATCH(EASTH ,EWALL , 20, 20, 1, 1, 1, 1, 1, 1)
 COVAL(EASTH ,H1 ,1. ,300. )
 XCYCLE = F
 EGWF = T
 WALLCO = GRND2
 ************************************************************
  Group 14. Downstream Pressure For PARAB
 ************************************************************
  Group 15. Terminate Sweeps
 LSWEEP = 25 ;ISWC1 = 1
 LITHYD = 1 ;LITFLX = 1 ;LITC = 1 ;ITHC1 = 1
 SELREF = T
 RESFAC =1.0E-04
 ************************************************************
  Group 16. Terminate Iterations
 LITER(H1)=20 ;LITER(RADX)=2
 ENDIT(H1)=1.0E-03 ;ENDIT(RADX)=1.0E-03
 ************************************************************
  Group 17. Relaxation
 RELAX(H1,FALSDT,0.04)
 RELAX(RADX,FALSDT,1.0E+09)
 OVRRLX =0.
 EXPERT = F ;NNORSL = F
 ************************************************************
  Group 18. Limits
 VARMAX(H1)=1.0E+10 ;VARMIN(H1)=-1.0E+10
 VARMAX(RADX)=1.0E+10 ;VARMIN(RADX)=-1.0E+10
 ************************************************************
  Group 19. Data transmitted to GROUND
 PARSOL = F
 ISG62 = 1
 ************************************************************
  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(H1,Y,Y,Y,Y,Y,Y)
 OUTPUT(RADX,Y,N,Y,Y,Y,Y)
 ************************************************************
  Group 22. Monitor Print-Out
 IXMON = 10 ;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
 NXPRIN = -1 ;IXPRF = 1 ;IXPRL = 10000
 IPLTF = 1 ;IPLTL = -1 ;NPLT = 2
 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(XWISE ,PROFIL, 1, 20, 1, 1, 1, 1, 1, 1)
 PLOT(XWISE ,H1 ,0. ,0. )
 PLOT(XWISE ,RADX,0. ,0. )
 ************************************************************
  Group 24. Dumps For Restarts
 SAVE = T ;NOWIPE = F
 NSAVE =CHAM
STOP