```
TALK=T;RUN(1,1)
PHOTON USE
p

msg             Numerical solution  contours
msg                     Time=1.
con C1 Z 1 fi;0.001
msg Press Enter to continue
PAUSE
CLEAR
con EXAC Z 1 fi;0.001
msg               Exact solution  contours
msg                      Time=1.
msg Press e to END
ENDUSE
DISPLAY
PLANT sets up and solves a 2D unsteady diffusion problem with
time-dependent source and boundary conditions and compares the
results with the exact solution.

The single dependent variable is C1

The "PLANTed" formulae are:
* at the west wall the value   = TIM*YG2D**2
* at the east wall the value   = TIM*(1.0+YG2D**2)
* at the south wall the value  = TIM*XG2D**2
* at the north wall the value  = TIM*(1.0+XG2D**2)
* within the volume the source = XG2D**2+YG2D**2-4.*TIM

* the exact solution           = TIM*(XG2D**2+YG2D**2)
ENDDIS
PLANTBEGIN
PATCH(WEST,WWALL,1,1,1,NY,1,NZ,1,LSTEP)
VAL=TIM*YG2D**2
COVAL(WEST,C1,1.,GRND)
PATCH(EAST,EWALL,NX,NX,1,NY,1,NZ,1,LSTEP)
VAL=TIM*(1.0+YG2D**2)
COVAL(EAST,C1,1.,GRND)
PATCH(SOUTH,SWALL,1,NX,1,1,1,NZ,1,LSTEP)
VAL=TIM*XG2D**2
COVAL(SOUTH,C1,1.,GRND)
PATCH(NORTH,NWALL,1,NX,NY,NY,1,NZ,1,LSTEP)
VAL=TIM*(1.0+XG2D**2)
COVAL(NORTH,C1,1.,GRND)
PATCH(SOURC,VOLUME,1,NX,1,NY,1,NZ,1,LSTEP)
VAL=XG2D**2+YG2D**2-4.*TIM
COVAL(SOURC,C1,FIXFLU,GRND)
STORE(EXAC)
EXAC=TIM*(XG2D**2+YG2D**2)
PLANTEND
************************************************************
Group 1. Run Title and Number
************************************************************
************************************************************

TEXT( 2D UNSTEADY DIFFUSION PROBLEM:119      )

************************************************************
************************************************************

IRUNN = 1 ;LIBREF = 119
************************************************************
Group 2. Time dependence
* Set overall time and no. of steps
TFIRST =0. ;TLAST =1.
FSTEP = 1 ;LSTEP = 5
TFRAC(1)=0.2 ;TFRAC(2)=0.4
TFRAC(3)=0.6 ;TFRAC(4)=0.8
TFRAC(5)=1.
************************************************************
Group 3. X-Direction Grid Spacing
CARTES = T
NX = 10
XULAST =1.
XFRAC(1)=0.1 ;XFRAC(2)=0.2
XFRAC(3)=0.3 ;XFRAC(4)=0.4
XFRAC(5)=0.5 ;XFRAC(6)=0.6
XFRAC(7)=0.7 ;XFRAC(8)=0.8
XFRAC(9)=0.9 ;XFRAC(10)=1.
************************************************************
Group 4. Y-Direction Grid Spacing
NY = 10
YVLAST =1.
YFRAC(1)=0.1 ;YFRAC(2)=0.2
YFRAC(3)=0.3 ;YFRAC(4)=0.4
YFRAC(5)=0.5 ;YFRAC(6)=0.6
YFRAC(7)=0.7 ;YFRAC(8)=0.8
YFRAC(9)=0.9 ;YFRAC(10)=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(16)=C1 ;NAME(150)=EXAC
* Y in SOLUTN argument list denotes:
* 1-stored 2-solved 3-whole-field
* 4-point-by-point 5-explicit 6-harmonic averaging
SOLUTN(C1,Y,Y,N,N,N,Y)
SOLUTN(EXAC,Y,N,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(C1,N,N,Y,Y,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 =0.
EL1 =0.
TSURR =0. ;TEMP0 =0.
PRESS0 =0.
DVO1DT =0. ;DRH1DP =0.
EMISS =0. ;SCATT =0.
ENUL =1. ;ENUT =0.
PRNDTL(C1)=1.
PRT(C1)=1.
CP1 =1. ;CP2 =1.
************************************************************
Group 10.Inter-Phase Transfer Processes
************************************************************
Group 11.Initial field variables (PHIs)
FIINIT(C1)=0. ;FIINIT(EXAC)=1.0E-10
No PATCHes yet used for this Group
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(WEST ,WWALL , 1, 1, 1, 10, 1, 1, 1, 5)
COVAL(WEST ,C1 ,1. , GRND )

PATCH(EAST ,EWALL , 10, 10, 1, 10, 1, 1, 1, 5)
COVAL(EAST ,C1 ,1. , GRND )

PATCH(SOUTH ,SWALL , 1, 10, 1, 1, 1, 1, 1, 5)
COVAL(SOUTH ,C1 ,1. , GRND )

PATCH(NORTH ,NWALL , 1, 10, 10, 10, 1, 1, 1, 5)
COVAL(NORTH ,C1 ,1. , GRND )

PATCH(SOURC ,VOLUME, 1, 10, 1, 10, 1, 1, 1, 5)
COVAL(SOURC ,C1 , FIXFLU , GRND )
XCYCLE = F
EGWF = T
WALLCO = GRND2
************************************************************
Group 14. Downstream Pressure For PARAB
************************************************************
Group 15. Terminate Sweeps
LSWEEP = 10 ;ISWC1 = 1
LITHYD = 1 ;LITFLX = 1 ;LITC = 1 ;ITHC1 = 1
SELREF = T
RESFAC =1.0E-04
************************************************************
Group 16. Terminate Iterations
LITER(C1)=20
ENDIT(C1)=1.0E-03
************************************************************
Group 17. Relaxation
RELAX(C1,FALSDT,1.0E+09)
RELAX(EXAC,LINRLX,1.)
OVRRLX =0.
EXPERT = F ;NNORSL = F
************************************************************
Group 18. Limits
VARMAX(C1)=1.0E+10 ;VARMIN(C1)=-1.0E+10
VARMAX(EXAC)=1.0E+10 ;VARMIN(EXAC)=-1.0E+10
************************************************************
Group 19. Data transmitted to GROUND
NAMSAT =MOSG
PARSOL = F
ISG62 = 1
SPEDAT(SET,GXMONI,TRANSIENT,L,F)
************************************************************
Group 20. Preliminary Printout
DISTIL = T ;NULLPR = F
NDST = 0
DSTTOL =1.0E-02
EX(C1)=0.6626 ;EX(EXAC)=0.665
************************************************************
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(C1,Y,N,Y,Y,Y,Y)
OUTPUT(EXAC,Y,N,Y,N,N,N)
************************************************************
Group 22. Monitor Print-Out
IXMON = 1 ;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 = 100000 ;ISTPRF = 1 ;ISTPRL = 100000
NXPRIN = -1 ;IXPRF = 1 ;IXPRL = 10000
NYPRIN = -1 ;IYPRF = 1 ;IYPRL = 10000
IPLTF = 1 ;IPLTL = -1 ;NPLT = -1
ISWPRF = 1 ;ISWPRL = 100000
ITABL = 3 ;IPROF = 1
ABSIZ =0.5 ;ORSIZ =0.4
NTZPRF = 1 ;NCOLPF = 50
ICHR = 2 ;NCOLCO = 45 ;NROWCO = 20
No PATCHes yet used for this Group
************************************************************
Group 24. Dumps For Restarts
SAVE = T ;NOWIPE = F
NSAVE =CHAM
STOP
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