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DISPLAY
'2-fluid' FLAME SPREAD IN PLANE CHANNEL
1-dimensional (x), cartesian, steady, elliptic simulation

This model concerns the turbulent spread of flame
through a pre-mixed combustible gas flowing steadily
into a plane-walled duct.

The first experiments of this kind were reported by
Williams, Hottel and Scurlock in 1948.

The major features of the phenomenon are represented
by the present simple 1D 2-fluid model.

enddis
AUTOPLOT USE
file
phi 5

cl
da 1 1u x 1 9
da 1 2u x 1 9
scale
cole 1
col8 2
msg velocity of hot gas - red
msg velocity of cold gas - green
msg Press  to continue
pause
cl
da 1 cold
scale
col4 1
msg volume fraction of cold gas
msg Press e to END
enduse
GROUP 1. Run title and other preliminaries
TEXT(Flame spread in duct, 1D analysis    )
TITLE
REAL(VELG,RHORAT,LENGTH,WIDTH,CHATIM)
VELG=10.0;RHORAT=0.2;LENGTH=1.0;WIDTH=0.05
mesg(Inlet velocity is :velg: m/s. OK? (y/n)
if(:ans:.eq.n) then
mesg(what value do you want?
mesg(Inlet velocity has been set to :velg: m/s
endif
mesg(Density ratio is :rhorat: . OK? (y/n)
if(:ans:.eq.n) then
mesg(Density ratio has been set to :rhorat:
endif
CHATIM=length/VELG/NX
GROUP 3. X-direction grid specification
GRDPWR(X,20,length,1.)
GROUP 4. Y-direction grid specification
yvlast=0.5*width
GROUP 7. Variables stored, solved & named
onephs=f;SOLVE(P1,U1,U2,r1,r2)
name(r1)=hot;name(r2)=cold
store(mdot)
GROUP 9. Properties of the medium (or media)
RHO2=1.0;rho1=rho1*rhorat
GROUP 10. Inter-phase-transfer processes and properties
** Set constant interphase friction factor and activate
the calculation of the interphase mass transfer by:
cfips=GRND2; cfipa=1.0;cfipc=1.e0;cmdot=30.0
cint(hot)=0.; cint(cold)=0.
GROUP 11. Initialization of variable or porosity fields
fiinit(hot)=0.1;fiinit(cold)=1.0-fiinit(hot);fiinit(p1)=velg
fiinit(U1)=VELG; fiinit(U2)=VELg; fiinit(mdot)=0.0
GROUP 13. Boundary conditions and special sources
** Inlets at the west end,
cold gas
PATCH(INLET,WEST,1,1,1,NY,1,1,1,1)
COVAL(INLET,P2,FIXFLU,RHO2*FIINIT(COLD)*VELG)
COVAL(INLET,U2,ONLYMS,VELG)
hot gas
COVAL(INLET,P1,FIXFLU,RHO1*FIINIT(HOT)*VELG)
COVAL(INLET,U1,ONLYMS,0.5*VELG/RHORAT)
** Outlet at east end
PATCH(OUTLET,CELL,NX,NX,1,1,1,1,1,1)
COVAL(OUTLET,P1,FIXP*RHO1,0.);COVAL(OUTLET,P2,FIXP*RHO2,0.)
COVAL(OUTLET,U1,ONLYMS,0.);COVAL(OUTLET,U2,ONLYMS,0.)
GROUP 15. Termination of sweeps
LSWEEP=100;SELREF=T; RESFAC=1.E-6
GROUP 17. Under-relaxation devices
RELAX(HOT,LINRLX,0.6);   RELAX(COLD,LINRLX,0.6)
RELAX(U1,FALSDT,CHATIM); RELAX(U2,FALSDT,CHATIM)
RELAX(MDOT,LINRLX,0.5)
GROUP 21. Print-out of variables
OUTPUT(MDOT,Y,Y,Y,Y,Y,Y);NAME(U1)=1U;NAME(U2)=2U
PATCH(PROFILS,PROFIL,1,NX,1,1,1,1,1,1)
PLOT(PROFILS,1U,-1.0,-1.0);PLOT(PROFILS,2U,-1.0,-1.0)
PLOT(PROFILS,COLD,0.0,1.0)
GROUP 22. Spot-value print-out
IXMON=NX/2;ITABL=1; ORSIZ=0.4;TSTSWP=-1

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