```

PHOTON USE
p

1 5 1

msg The grid (magnified by 5 in the y direction)
gr z 1
msg Press  to continue
pause
cl
msg Velocity vector field
set vec ref 0.4
gr ou z 1
vec z 1 sh
msg Press  to continue
pause
cl
msg Concentration contours of particle 1
gr ou z 1
con pt1 z 1 fi;0.01
msg Press  to continue
pause
cl
msg Concentration contours of particle 2
gr ou z 1
con pt2 z 1 fi;0.01
msg Press  to continue
pause
cl
msg Concentration contours of particle 3
gr ou z 1
con pt3 z 1 fi;0.01
msg Press e to END
enduse

GROUP 1. Run title and other preliminaries
TEXT(Particle accumulation along duct walls:P108
TITLE
DISPLAY
2-dimensional (x-y), Cartesian, steady, elliptic simulation

This case calculates the accumulation of particles in a flow in
which the particle-slip velocities are normal to the main flow
direction, which is from low to high x. Three groups of particles,
of different densities but the same diameter, are included. They
are such that the first group is denser than the continuous phase,
the second group is neutrally buoyant and the third group is less
dense.

/////////////////////////
------------------------- north wall
y^
|    --> in                      --> out (3 exits)
|
---->   ------------------------- south wall
x   /////////////////////////
ENDDIS

nx=10; xulast=5.0; ny=10; yvlast=0.2; nz=1; zwlast=1.0
#unigrid

#aslp0
defaults
npt=3; rho2=1000.
#aslp1
GROUP 9. Properties of the medium (or media)
dens0=1000.0; diam0=1.0   ; visc0= 1.e-5
dens1=2000.0; diam1=1.0e-4; visc1= 2.e-5 ; vfrac1=0.2
dens2=1000.0; diam2=1.0e-4; visc2= 1.e-5 ; vfrac2=0.001
dens3=500.0 ; diam3=1.2e-4; visc3= 1.e-6 ; vfrac3=0.2
#aslp2
mesg(rhom= :rhom:  vfrac0= :vfrac0:

GROUP 11. Initialisation of variable or porosity fields
REAL(UIN); UIN=2.0e-1
FIINIT(P1)=10000.0; FIINIT(U1)=UIN; FIINIT(V1)=0.0
FIINIT(PT0)=VFRAC0; FIINIT(PT1)=VFRAC1; FIINIT(PT2)=VFRAC2
FIINIT(PT3)=VFRAC3
GROUP 13. Boundary conditions and special sources
** Inlet
PATCH(ASMIN,WEST,1,1,1,NY,1,1,1,LSTEP)
COVAL(ASMIN, P1 ,FIXFLU, UIN*RHOM); COVAL(ASMIN, U1 ,ONLYMS, UIN)
patnam=asmin
#aslp3
** Outlets
PATCH(ASMOU1,EAST,NX,NX,1,1,1,1,1,LSTEP)
COVAL(ASMOU1,P1,1.E1,2000.0)

PATCH(ASMOU2,EAST,NX,NX,NY,NY,1,1,1,LSTEP)
COVAL(ASMOU2,P1,1.E1,0.0)

PATCH(ASMOU3,EAST,NX,NX,NY/2,NY/2,1,1,1,LSTEP)
COVAL(ASMOU3,P1,1.E1,1000.0)

#gravity
gravdir=2
#density

GROUP 15. Termination of sweeps
LSWEEP=70
RESREF(P1)=1.E-8; RESREF(U1)=1.e-8; RESREF(V1)=1.e-8
RESREF(PT0)=1.e-8; RESREF(PT1)=1.e-8
LITER(PT0)=2; LITER(PT1)=5; ENDIT(PT0)=1.E-8; ENDIT(PT1)=1.E-5
GROUP 17. Under-relaxation devices
RELAX(P1,LINRLX,1.0); RELAX( U1,FALSDT,1.0); RELAX(V1,FALSDT,1.0)
RELAX(PT0,LINRLX,0.5); RELAX(PT1,LINRLX,0.5)
GROUP 21. Print-out of variables
OUTPUT(VFOL,N,N,y,N,N,N)
GROUP 22. Spot-value print-out
TSTSWP=-1;IXMON=NX/2; IYMON=2
GROUP 23. Field print-out and plot control
IPLTF=2;IPLTL=LSWEEP;YZPR=T;IPROF=1
GROUP 24. Dumps for restarts
NXPRIN=1; NYPRIN=1; SELREF=F; RESFAC=1.E-2
```