```

GROUP 1. Run title and other preliminaries
TEXT(Pot. Flow; Perpendicular Plate. USP Test 12
#cls
TITLE
DISPLAY
An inviscid fluid flows steadily in a direction normal to a flat
plate. Since the potential-flow equation involves only diffusion-
type terms, sources, convection and transient terms are switched
off automatically within EARTH.

The geometry of the problem is as follows:

frictionless wall
-----------------------------------------------------

-------->
---->                  -------->              ---->

^  ---->                   Plate                 ---->
|                            |
y| ---------------------------|-------------------------
|                    frictionless wall
z--->
The plate is introduced by the setting of PRPS=199
for the appropriate cells.

ENDDIS
#pause
GROUPs 3, 4 and 5: grid specification
nx=1; ny=40; nz=80
xulast=1.0; yvlast=4.0; zwlast=8.0
#unigrid

GROUP 7. Variables stored, solved & named
STORE(POT,PRPS,V1,W1); SOLUTN(POT,Y,Y,Y,N,N,N)

Usp related variables
USP    = T
UAUTO  = F
USPDBG = F
UTCPLT = T
USPVTK = T
USPIMB = F
MXLEV  = 0
MYLEV  = 0
MZLEV  = 0
DOMAT  = -1
MINPRP = -1
MAXPRP = 250
CELLST = 10
FACEST = 10

mesg(Do you want to view results in the centres of cells? (y/n)
if(:ans:.eq.y)then
SPEDAT(SET,USPIO,VERTCENT,L,F)
endif

GROUP 11. Initialization of variable or porosity fields
FIINIT(PRPS)=-1.0
**Plate
PATCH(PLATE,INIVAL,1,1,1,NY/4,NZ/2,NZ/2,1,1)
INIT(PLATE,PRPS,FIXVAL,199)
REAL(HEIGHT);INTEGER(IYTOP)
mesga(Plate height = 0.5 * domain height. OK?
mesg(If not, insert new factor
IF(HEIGHT.GE.1.) THEN
+ HEIGHT=0.9
mesg(Factor has been re-set to 0.9
ENDIF
HEIGHT=NY*HEIGHT; IYTOP = HEIGHT
PATCH(PLATE,INIVAL,1,1,1,IYTOP,NZ/2,NZ/2,1,1)
INIT(PLATE,PRPS,FIXVAL,199)

GROUP 13. Boundary conditions and special sources
**Upstream boundary
PATCH(UPSTRM,LOW,1,1,1,NY,1,1,1,1)
COVAL(UPSTRM,POT,FIXVAL,4.0)
**Downstream boundary
PATCH(DWNSTRM,HIGH,1,1,1,NY,NZ,NZ,1,1)
COVAL(DWNSTRM,POT,FIXVAL,-4.0)

GROUP 15. Termination of sweeps
LSWEEP = 200
POTVEL=T
GROUP 16. Termination of iterations
LITER(POT)=500
SELREF = T; RESFAC =1.0E-15
ECHO=T;IZMON=NZ/3;IYMON=NY/2
TSTSWP=-1
NXPRIN= 1; NYPRIN=1
GROUP 24. Dumps for restart
STOP
```