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

msg streamlines and potential contours for flow around a cylinder

gr ou x 1
msg streamlines
stre 2d x 1 sh;-1 0 20
pause
msg constant-potential contours
con pot x 1 sh;-0.95 0.95 20
msg
msg Press e to END
ENDUSE
DISPLAY

******************************************************************
*  Plane potential flow around a closely spaced source-sink pair,*
*  within a uniform-potential-gradient field, is known to        *
*  generate a field in which a closed stream-line has the shape  *
*  of a circular cylinder.                                       *
*                                                                *
*  This is illustrated in the present case.                      *
*                                                                *
*  A PHOTON USE file is provided to facilitate display.          *
*                                                                *
******************************************************************

ENDDIS
************************************************************
Group 1. Run Title and Number
************************************************************
************************************************************

TEXT(Potl. 2D Flow; Source-Sink Pair         )

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

IRUNN = 1 ;LIBREF = 0
************************************************************
Group 2. Time dependence
************************************************************
Group 3. X-Direction Grid Spacing
CARTES = T
NX = 1
XULAST =1.
XFRAC(1)=1.
************************************************************
Group 4. Y-Direction Grid Spacing
NY = 40
YVLAST =1.
YFRAC(1)=0.025 ;YFRAC(2)=0.05
YFRAC(3)=0.075 ;YFRAC(4)=0.1
YFRAC(5)=0.125 ;YFRAC(6)=0.15
YFRAC(7)=0.175 ;YFRAC(8)=0.2
YFRAC(9)=0.225 ;YFRAC(10)=0.25
YFRAC(11)=0.275 ;YFRAC(12)=0.3
YFRAC(13)=0.325 ;YFRAC(14)=0.35
YFRAC(15)=0.375 ;YFRAC(16)=0.4
YFRAC(17)=0.425 ;YFRAC(18)=0.45
YFRAC(19)=0.475 ;YFRAC(20)=0.5
YFRAC(21)=0.525 ;YFRAC(22)=0.55
YFRAC(23)=0.575 ;YFRAC(24)=0.6
YFRAC(25)=0.625 ;YFRAC(26)=0.65
YFRAC(27)=0.675 ;YFRAC(28)=0.7
YFRAC(29)=0.725 ;YFRAC(30)=0.75
YFRAC(31)=0.775 ;YFRAC(32)=0.8
YFRAC(33)=0.825 ;YFRAC(34)=0.85
YFRAC(35)=0.875 ;YFRAC(36)=0.9
YFRAC(37)=0.925 ;YFRAC(38)=0.95
YFRAC(39)=0.975 ;YFRAC(40)=1.
************************************************************
Group 5. Z-Direction Grid Spacing
PARAB = F
NZ = 80
ZWLAST =2.
ZFRAC(1)=0.0125 ;ZFRAC(2)=0.025
ZFRAC(3)=0.0375 ;ZFRAC(4)=0.05
ZFRAC(5)=0.0625 ;ZFRAC(6)=0.075
ZFRAC(7)=0.0875 ;ZFRAC(8)=0.1
ZFRAC(9)=0.1125 ;ZFRAC(10)=0.125
ZFRAC(11)=0.1375 ;ZFRAC(12)=0.15
ZFRAC(13)=0.1625 ;ZFRAC(14)=0.175
ZFRAC(15)=0.1875 ;ZFRAC(16)=0.2
ZFRAC(17)=0.2125 ;ZFRAC(18)=0.225
ZFRAC(19)=0.2375 ;ZFRAC(20)=0.25
ZFRAC(21)=0.2625 ;ZFRAC(22)=0.275
ZFRAC(23)=0.2875 ;ZFRAC(24)=0.3
ZFRAC(25)=0.3125 ;ZFRAC(26)=0.325
ZFRAC(27)=0.3375 ;ZFRAC(28)=0.35
ZFRAC(29)=0.3625 ;ZFRAC(30)=0.375
ZFRAC(31)=0.3875 ;ZFRAC(32)=0.4
ZFRAC(33)=0.4125 ;ZFRAC(34)=0.425
ZFRAC(35)=0.4375 ;ZFRAC(36)=0.45
ZFRAC(37)=0.4625 ;ZFRAC(38)=0.475
ZFRAC(39)=0.4875 ;ZFRAC(40)=0.5
ZFRAC(41)=0.5125 ;ZFRAC(42)=0.525
ZFRAC(43)=0.5375 ;ZFRAC(44)=0.55
ZFRAC(45)=0.5625 ;ZFRAC(46)=0.575
ZFRAC(47)=0.5875 ;ZFRAC(48)=0.6
ZFRAC(49)=0.6125 ;ZFRAC(50)=0.625
ZFRAC(51)=0.6375 ;ZFRAC(52)=0.65
ZFRAC(53)=0.6625 ;ZFRAC(54)=0.675
ZFRAC(55)=0.6875 ;ZFRAC(56)=0.7
ZFRAC(57)=0.7125 ;ZFRAC(58)=0.725
ZFRAC(59)=0.7375 ;ZFRAC(60)=0.75
ZFRAC(61)=0.7625 ;ZFRAC(62)=0.775
ZFRAC(63)=0.7875 ;ZFRAC(64)=0.8
ZFRAC(65)=0.8125 ;ZFRAC(66)=0.825
ZFRAC(67)=0.8375 ;ZFRAC(68)=0.85
ZFRAC(69)=0.8625 ;ZFRAC(70)=0.875
ZFRAC(71)=0.8875 ;ZFRAC(72)=0.9
ZFRAC(73)=0.9125 ;ZFRAC(74)=0.925
ZFRAC(75)=0.9375 ;ZFRAC(76)=0.95
ZFRAC(77)=0.9625 ;ZFRAC(78)=0.975
ZFRAC(79)=0.9875 ;ZFRAC(80)=1.
************************************************************
Group 6. Body-Fitted Coordinates
************************************************************
Group 7. Variables: STOREd,SOLVEd,NAMEd
ONEPHS = T
NAME(3)=U1 ;NAME(5)=V1
NAME(7)=W1 ;NAME(150)=POT
* Y in SOLUTN argument list denotes:
* 1-stored 2-solved 3-whole-field
* 4-point-by-point 5-explicit 6-harmonic averaging
SOLUTN(U1,Y,N,N,N,N,Y)
SOLUTN(V1,Y,N,N,N,N,Y)
SOLUTN(W1,Y,N,N,N,N,Y)
SOLUTN(POT,Y,Y,Y,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(POT,N,N,Y,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 =1.0E-05 ;ENUT =0.
PRNDTL(POT)=1.
PRT(POT)=1.
CP1 =1. ;CP2 =1.
************************************************************
Group 10.Inter-Phase Transfer Processes
************************************************************
Group 11.Initial field variables (PHIs)
FIINIT(U1)=1.0E-10 ;FIINIT(V1)=1.0E-10
FIINIT(W1)=1.0E-10 ;FIINIT(POT)=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(UPSTRM ,LOW , 1, 1, 1, 40, 1, 1, 1, 1)
COVAL(UPSTRM ,POT , FIXVAL ,1. )

PATCH(DWNSTRM ,HIGH , 1, 1, 1, 40, 80, 80, 1, 1)
COVAL(DWNSTRM ,POT , FIXVAL ,-1. )

PATCH(SOURCE1 ,CELL , 1, 1, 1, 1, 40, 40, 1, 1)
COVAL(SOURCE1 ,POT , FIXFLU ,10. )

PATCH(SINK1 ,CELL , 1, 1, 1, 1, 41, 41, 1, 1)
COVAL(SINK1 ,POT , FIXFLU ,-10. )
XCYCLE = F
EGWF = T
WALLCO = GRND2
************************************************************
Group 14. Downstream Pressure For PARAB
************************************************************
Group 15. Terminate Sweeps
LSWEEP = 3 ;ISWC1 = 1
LITHYD = 1 ;LITFLX = 1 ;LITC = 1 ;ITHC1 = 1
SELREF = T
RESFAC =1.0E-02
************************************************************
Group 16. Terminate Iterations
LITER(POT)=-100
ENDIT(POT)=1.0E-03
************************************************************
Group 17. Relaxation
RELAX(U1,LINRLX,1.)
RELAX(V1,LINRLX,1.)
RELAX(W1,LINRLX,1.)
RELAX(POT,FALSDT,1.0E+09)
OVRRLX =0.
EXPERT = F ;NNORSL = F
************************************************************
Group 18. Limits
VARMAX(U1)=1.0E+06 ;VARMIN(U1)=-1.0E+06
VARMAX(V1)=1.0E+06 ;VARMIN(V1)=-1.0E+06
VARMAX(W1)=1.0E+06 ;VARMIN(W1)=-1.0E+06
VARMAX(POT)=1.0E+10 ;VARMIN(POT)=-1.0E+10
************************************************************
Group 19. Data transmitted to GROUND
POTVEL = T
PARSOL = F
ISG62 = 1
CSG3    ='CNGR'
************************************************************
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(U1,Y,N,N,N,N,N)
OUTPUT(V1,Y,N,N,N,N,N)
OUTPUT(W1,Y,N,N,N,N,N)
OUTPUT(POT,Y,N,N,N,N,N)
************************************************************
Group 22. Monitor Print-Out
IXMON = 5 ;IYMON = 5 ;IZMON = 5
NPRMON = 100000 ;NPRMNT = 1 ;TSTSWP = 1
UWATCH = T ;USTEER = T
HIGHLO = F
************************************************************
Group 23.Field Print-Out & Plot Control
NPRINT = 100000 ;NUMCLS = 5
NYPRIN = -1 ;IYPRF = 1 ;IYPRL = 10000
NZPRIN = -1 ;IZPRF = 1 ;IZPRL = 10000
XZPR = F ;YZPR = T
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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