```
GROUP 1. Run title and other preliminaries
TEXT(Backward-Facing STP KE MDL Y-X POS
TITLE
See case 290 for explanation and diagram.
INTEGER(NYS,NXS)
REAL(HEIGHT,WIDTH,CLEN,SLEN,REYNO,GVISL,UIN,TKEIN,EPSIN)
** Calculation of domain specifications
REYNO=4.5E4;UIN=13.;HEIGHT=0.0381;WIDTH=3.*HEIGHT
NXS=4;NYS=10;SLEN=4.*HEIGHT;CLEN=20.*HEIGHT

GROUP 3. X-direction grid specification
** Full length of channel = 0.762
NREGX=2
IREGX=1;GRDPWR(X,NXS,SLEN,1.0)
IREGX=2;GRDPWR(X,16,CLEN-SLEN,1.0)

GROUP 4. Y-direction grid specification
** Full width of channel = 0.1143
NREGY=2
IREGY=1;GRDPWR(Y,NYS,HEIGHT,1.0)
IREGY=2;GRDPWR(Y,5,WIDTH-HEIGHT,1.0)

GROUP 7. Variables stored, solved & named
SOLVE(P1,U1,V1);SOLUTN(P1,Y,Y,Y,N,N,N);STORE(ENUT);TURMOD(KEMODL)
ISOLX=1;ISOLY=1

GROUP 8. Terms (in differential equations) & devices
DIFCUT=0

GROUP 9. Properties of the medium (or media)
RHO1=1.0;GVISL=UIN*HEIGHT;GVISL=GVISL/REYNO;ENUL=GVISL

GROUP 11. Initialization of variable or porosity fields
CONPOR(0.0,VOLUME,1,-NXS,1,-NYS,1,1)
** Calculation of KE (where fric=0.018)...
TKEIN=0.25*UIN;TKEIN=TKEIN*UIN;TKEIN=TKEIN*0.018
** Calculation of EP (where lmix=0.09 x h)...
EPSIN=TKEIN**1.5;EPSIN=EPSIN*0.1643;EPSIN=EPSIN/3.429E-3
** Initial values
FIINIT(U1)=UIN;FIINIT(P1)=1.3E-4
FIINIT(EP)=EPSIN;FIINIT(KE)=TKEIN

GROUP 13. Boundary conditions and special sources
** Inlet
INLET(INLET,WEST,1,1,NYS+1,NY,1,1,1,1)
VALUE(INLET,P1,UIN);VALUE(INLET,U1,UIN)
VALUE(INLET,KE,TKEIN);VALUE(INLET,EP,EPSIN)
** Exit
PATCH(OUTLET,EAST,NX,NX,1,NY,1,1,1,1);COVAL(OUTLET,P1,1.0E+05,0.0)
COVAL(OUTLET,U1,ONLYMS,0.0);COVAL(OUTLET,V1,ONLYMS,0.0)
COVAL(OUTLET,KE,ONLYMS,0.0);COVAL(OUTLET,EP,ONLYMS,0.0)
** N-wall
WALL (WFUNNORT,NORTH,1,NX,NY,NY,1,1,1,1)
** S2-wall
WALL (WFUNSOUT,SOUTH,NXS+1,NX,1,1,1,1,1,1)

GROUP 15. Termination of sweeps
LSWEEP=20

GROUP 17. Under-relaxation devices
RELAX(P1,LINRLX,0.5);RELAX(U1,FALSDT,0.01);RELAX(V1,FALSDT,0.01)
RELAX(KE,FALSDT,0.01);RELAX(EP,FALSDT,0.01)

GROUP 22. Monitor print-out
IXMON=NXS+2;ITABL=2;IPLTL=1000;IYMON=NYS-2
NPLT=5;NPRMON=10000

GROUP 23. Field print-out and plot control
NXPRIN=NX/5;NYPRIN=NY/5;NZPRIN=NZ/5
```