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

msg             Numerical solution  contours
con c1 z 1 fi;0.1
msg  Press Enter to continue
pause;clear;con errr z 1 fi;0.1
msg               Error contours. Press e to END
ENDUSE
DISPLAY
A two-dimensional transient diffusion problem with time-dependen
boundary conditions and space-dependent initial fields is used a
an illustration of how PLANT statements can be used to:-

* set initial fields;
* set boundary conditions and other sources;
* make comparisons with exact solutions.

The analytical solution is: C1 = X + Y + T ,
where X and Y are cartesian coordinates and T is time.

The C1 computed by PHOENICS, the exact solution (EXAC) and the
difference between them (ERRR) are all printed out.

The GROUND coding which the PLANT statements generate is
appended to the Q1 file.

This case enables the influences on accuracy to be investigated
of numerical settings such as LITER(C1), RESFAC, ISOLX, ISOLY &
CSG3. The latter, when set = CNGR, activates the conjugate-
ENDDIS
PLANTBEGIN
solve(errr);store(exac)
PLANT.. Following commands set the initial field as.. C1 = X + Y
PATCH(INIT,INIVAL,1,NX,1,NY,1,NZ,1,1)
VAL=XG2D+YG2D
INIT(INIT,C1,0.0,GRND)
VAL=XG2D+YG2D+TLAST
INIT(INIT,EXAC,0.0,GRND)

GROUP 13. Boundary conditions and special sources
PLANT.. Following commands set the west values as.. C1 = T + Y
PATCH(WEST,WWALL,1,1,1,NY,1,NZ,1,LSTEP)
VAL=TIM+YG2D
COVAL(WEST,C1,1.,GRND)

PLANT.. Following commands set the east values as.. C1 = T + 1 + Y
PATCH(EAST,EWALL,NX,NX,1,NY,1,NZ,1,LSTEP)
VAL=TIM+1.0+YG2D
COVAL(EAST,C1,1.,GRND)

PLANT.. Following commands set south values as.. C1 = T + X
PATCH(SOUTH,SWALL,1,NX,1,1,1,NZ,1,LSTEP)
VAL=TIM+XG2D
COVAL(SOUTH,C1,1.,GRND)

PLANT.. Following commands set north values as.. C1 = T + 1 + X
PATCH(NORTH,NWALL,1,NX,NY,NY,1,NZ,1,LSTEP)
VAL=TIM+1.0+XG2D
COVAL(NORTH,C1,1.,GRND)

PLANT.. Following commands set field values of EXAC as.. T + 1 + Y
PATCH(ERROR,CELL,1,NX,1,NY,1,NZ,1,LSTEP)
VAL=TIM+XG2D+YG2D-C1
COVAL(ERROR,ERRR,FIXVAL,GRND)
PLANTEND
************************************************************
Group 1. Run Title and Number
************************************************************
************************************************************

TEXT( 2D UNSTEADY DIFFUSION PROBLEM:Z104     )

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

IRUNN = 1 ;LIBREF = 104
************************************************************
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 = 100
XULAST =1.
XFRAC(1)=1.0E-02 ;XFRAC(2)=0.02
XFRAC(3)=0.03 ;XFRAC(4)=0.04
XFRAC(5)=0.05 ;XFRAC(6)=0.06
XFRAC(7)=0.07 ;XFRAC(8)=0.08
XFRAC(9)=0.09 ;XFRAC(10)=0.1
XFRAC(11)=0.11 ;XFRAC(12)=0.12
XFRAC(13)=0.13 ;XFRAC(14)=0.14
XFRAC(15)=0.15 ;XFRAC(16)=0.16
XFRAC(17)=0.17 ;XFRAC(18)=0.18
XFRAC(19)=0.19 ;XFRAC(20)=0.2
XFRAC(21)=0.21 ;XFRAC(22)=0.22
XFRAC(23)=0.23 ;XFRAC(24)=0.24
XFRAC(25)=0.25 ;XFRAC(26)=0.26
XFRAC(27)=0.27 ;XFRAC(28)=0.28
XFRAC(29)=0.29 ;XFRAC(30)=0.3
XFRAC(31)=0.31 ;XFRAC(32)=0.32
XFRAC(33)=0.33 ;XFRAC(34)=0.34
XFRAC(35)=0.35 ;XFRAC(36)=0.36
XFRAC(37)=0.37 ;XFRAC(38)=0.38
XFRAC(39)=0.39 ;XFRAC(40)=0.4
XFRAC(41)=0.41 ;XFRAC(42)=0.42
XFRAC(43)=0.43 ;XFRAC(44)=0.44
XFRAC(45)=0.45 ;XFRAC(46)=0.46
XFRAC(47)=0.47 ;XFRAC(48)=0.48
XFRAC(49)=0.49 ;XFRAC(50)=0.5
XFRAC(51)=0.51 ;XFRAC(52)=0.52
XFRAC(53)=0.53 ;XFRAC(54)=0.54
XFRAC(55)=0.55 ;XFRAC(56)=0.56
XFRAC(57)=0.57 ;XFRAC(58)=0.58
XFRAC(59)=0.59 ;XFRAC(60)=0.6
XFRAC(61)=0.61 ;XFRAC(62)=0.62
XFRAC(63)=0.63 ;XFRAC(64)=0.64
XFRAC(65)=0.65 ;XFRAC(66)=0.66
XFRAC(67)=0.67 ;XFRAC(68)=0.68
XFRAC(69)=0.69 ;XFRAC(70)=0.7
XFRAC(71)=0.71 ;XFRAC(72)=0.72
XFRAC(73)=0.73 ;XFRAC(74)=0.74
XFRAC(75)=0.75 ;XFRAC(76)=0.76
XFRAC(77)=0.77 ;XFRAC(78)=0.78
XFRAC(79)=0.79 ;XFRAC(80)=0.8
XFRAC(81)=0.81 ;XFRAC(82)=0.82
XFRAC(83)=0.83 ;XFRAC(84)=0.84
XFRAC(85)=0.85 ;XFRAC(86)=0.86
XFRAC(87)=0.87 ;XFRAC(88)=0.88
XFRAC(89)=0.89 ;XFRAC(90)=0.9
XFRAC(91)=0.91 ;XFRAC(92)=0.92
XFRAC(93)=0.93 ;XFRAC(94)=0.94
XFRAC(95)=0.95 ;XFRAC(96)=0.96
XFRAC(97)=0.97 ;XFRAC(98)=0.98
XFRAC(99)=0.99 ;XFRAC(100)=1.
************************************************************
Group 4. Y-Direction Grid Spacing
NY = 100
YVLAST =1.
YFRAC(1)=1.0E-02 ;YFRAC(2)=0.02
YFRAC(3)=0.03 ;YFRAC(4)=0.04
YFRAC(5)=0.05 ;YFRAC(6)=0.06
YFRAC(7)=0.07 ;YFRAC(8)=0.08
YFRAC(9)=0.09 ;YFRAC(10)=0.1
YFRAC(11)=0.11 ;YFRAC(12)=0.12
YFRAC(13)=0.13 ;YFRAC(14)=0.14
YFRAC(15)=0.15 ;YFRAC(16)=0.16
YFRAC(17)=0.17 ;YFRAC(18)=0.18
YFRAC(19)=0.19 ;YFRAC(20)=0.2
YFRAC(21)=0.21 ;YFRAC(22)=0.22
YFRAC(23)=0.23 ;YFRAC(24)=0.24
YFRAC(25)=0.25 ;YFRAC(26)=0.26
YFRAC(27)=0.27 ;YFRAC(28)=0.28
YFRAC(29)=0.29 ;YFRAC(30)=0.3
YFRAC(31)=0.31 ;YFRAC(32)=0.32
YFRAC(33)=0.33 ;YFRAC(34)=0.34
YFRAC(35)=0.35 ;YFRAC(36)=0.36
YFRAC(37)=0.37 ;YFRAC(38)=0.38
YFRAC(39)=0.39 ;YFRAC(40)=0.4
YFRAC(41)=0.41 ;YFRAC(42)=0.42
YFRAC(43)=0.43 ;YFRAC(44)=0.44
YFRAC(45)=0.45 ;YFRAC(46)=0.46
YFRAC(47)=0.47 ;YFRAC(48)=0.48
YFRAC(49)=0.49 ;YFRAC(50)=0.5
YFRAC(51)=0.51 ;YFRAC(52)=0.52
YFRAC(53)=0.53 ;YFRAC(54)=0.54
YFRAC(55)=0.55 ;YFRAC(56)=0.56
YFRAC(57)=0.57 ;YFRAC(58)=0.58
YFRAC(59)=0.59 ;YFRAC(60)=0.6
YFRAC(61)=0.61 ;YFRAC(62)=0.62
YFRAC(63)=0.63 ;YFRAC(64)=0.64
YFRAC(65)=0.65 ;YFRAC(66)=0.66
YFRAC(67)=0.67 ;YFRAC(68)=0.68
YFRAC(69)=0.69 ;YFRAC(70)=0.7
YFRAC(71)=0.71 ;YFRAC(72)=0.72
YFRAC(73)=0.73 ;YFRAC(74)=0.74
YFRAC(75)=0.75 ;YFRAC(76)=0.76
YFRAC(77)=0.77 ;YFRAC(78)=0.78
YFRAC(79)=0.79 ;YFRAC(80)=0.8
YFRAC(81)=0.81 ;YFRAC(82)=0.82
YFRAC(83)=0.83 ;YFRAC(84)=0.84
YFRAC(85)=0.85 ;YFRAC(86)=0.86
YFRAC(87)=0.87 ;YFRAC(88)=0.88
YFRAC(89)=0.89 ;YFRAC(90)=0.9
YFRAC(91)=0.91 ;YFRAC(92)=0.92
YFRAC(93)=0.93 ;YFRAC(94)=0.94
YFRAC(95)=0.95 ;YFRAC(96)=0.96
YFRAC(97)=0.97 ;YFRAC(98)=0.98
YFRAC(99)=0.99 ;YFRAC(100)=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(149)=EXAC
NAME(150)=ERRR
* 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)
SOLUTN(ERRR,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(C1,N,N,Y,Y,Y,Y)
TERMS(ERRR,N,N,N,Y,Y,Y)
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)=1.0E-10 ;FIINIT(EXAC)=1.0E-10
FIINIT(ERRR)=1.0E-10

PATCH(INIT ,INIVAL, 1, 100, 1, 100, 1, 1, 1, 1)
INIT(INIT ,C1 ,0. ,0. )
INIT(INIT ,EXAC,0. ,0. )

PATCH(IINIT ,INIVAL, 1, 100, 1, 100, 1, 1, 1, 1)
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, 100, 1, 1, 1, 5)
COVAL(WEST ,C1 ,0. ,0. )

PATCH(EAST ,EWALL , 100, 100, 1, 100, 1, 1, 1, 5)
COVAL(EAST ,C1 ,0. ,0. )

PATCH(SOUTH ,SWALL , 1, 100, 1, 1, 1, 1, 1, 5)
COVAL(SOUTH ,C1 ,0. ,0. )

PATCH(NORTH ,NWALL , 1, 100, 100, 100, 1, 1, 1, 5)
COVAL(NORTH ,C1 ,0. ,0. )

PATCH(SOURC ,VOLUME, 1, 100, 1, 100, 1, 1, 1, 5)
COVAL(SOURC ,C1 , FIXFLU ,1. )

PATCH(IWEST ,WWALL , 1, 1, 1, 100, 1, 1, 1, 5)
COVAL(IWEST ,C1 ,In-Form:source - see Grp 19)

PATCH(IEAST ,EWALL , 100, 100, 1, 100, 1, 1, 1, 5)
COVAL(IEAST ,C1 ,In-Form:source - see Grp 19)

PATCH(ISOUTH ,SWALL , 1, 100, 1, 1, 1, 1, 1, 5)
COVAL(ISOUTH ,C1 ,In-Form:source - see Grp 19)

PATCH(INORTH ,NWALL , 1, 100, 100, 100, 1, 1, 1, 5)
COVAL(INORTH ,C1 ,In-Form:source - see Grp 19)

PATCH(IERROR ,CELL , 1, 100, 1, 100, 1, 1, 1, 5)
COVAL(IERROR ,ERRR,In-Form:source - see Grp 19)
XCYCLE = F
EGWF = T
WALLCO = GRND2
************************************************************
Group 14. Downstream Pressure For PARAB
************************************************************
Group 15. Terminate Sweeps
LSWEEP = 5 ;ISWC1 = 1
LITHYD = 1 ;LITFLX = 1 ;LITC = 1 ;ITHC1 = 1
SELREF = T
RESFAC =1.0E-06
************************************************************
Group 16. Terminate Iterations
LITER(C1)=10 ;LITER(ERRR)=20
ENDIT(C1)=1.0E-03 ;ENDIT(ERRR)=1.0E-03
************************************************************
Group 17. Relaxation
RELAX(C1,FALSDT,1.0E+09)
RELAX(EXAC,LINRLX,1.)
RELAX(ERRR,FALSDT,1.0E+09)
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
VARMAX(ERRR)=1.0E+10 ;VARMIN(ERRR)=-1.0E+10
************************************************************
Group 19. Data transmitted to GROUND
PARSOL = F
ISG62 = 1
CSG3    ='CNGR'
SPEDAT(SET,GXMONI,TRANSIENT,L,F)
SPEDAT(SET,INITIAL,C1!IINIT,C,=XG+YG)
SPEDAT(SET,INITIAL,EXAC!IINIT,C,=XG+YG+TLAST)
SPEDAT(SET,SOURCE,C1!IWEST,C,=(TIM+YG-C1)*2./DXG!LINE)
SPEDAT(SET,SOURCE,C1!IEAST,C,=(TIM+1.0+YG-C1)*2./DXG!LINE)
SPEDAT(SET,SOURCE,C1!ISOUTH,C,=(TIM+XG-C1)*2./DYG!LINE)
SPEDAT(SET,SOURCE,C1!INORTH,C,=(TIM+1.0+XG-C1)*2./DYG!LINE)
SPEDAT(SET,SOURCE,ERRR!IERROR,C,=TIM+XG+YG-C1!FIXVAL)
************************************************************
Group 20. Preliminary Printout
DISTIL = T ;NULLPR = F
NDST = 0
DSTTOL =1.0E-02
EX(C1)=2. ;EX(EXAC)=2.
EX(ERRR)=9.861E-03
************************************************************
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,Y,Y,Y,Y,Y)
OUTPUT(EXAC,Y,N,Y,N,N,N)
OUTPUT(ERRR,Y,N,Y,N,N,N)
************************************************************
Group 22. Monitor Print-Out
IXMON = 50 ;IYMON = 50 ;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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