GROUP 1. Run title and other preliminaries
TEXT(Ricou's Jet In Cylindrical Chamber
TITLE
real(winj,rhoinj,walvel,reyno,jetdiam,denrat)
rhoinj=1.0; winj=50.0
DISPLAY
F Ricou (London University PhD thesis 1959) injected gases into
a porous-walled cylindrical chamber with a circular exit opposite
the injection orifice. He varied the inflow rate of air through
the porous wall until the pressure in the chamber equalled that
outside, and took this to be the rate of entrainment of air into
jet.
When the flow was turbulent, he found that the rate of entrain-
ment per unit length equalled 0.32 times the mass-injection rate
divided by the nozzle diameter, if the injected fluid had the
same density as the surrounding fluid.
Please press RETURN to continue
readvdu(nphi,int,nphi)
When the densities differed he found that the 0.32 factor should
be replaced by:
0.32 * (surrounding-fluid density/injected-fluid density)**0.5
This Q1 file causes PHOENICS to simulate the conditions of the
experiment. The Reynolds number and density ratio can be varied.
The Prandtl mixing-length model of turbulence is used, with the
low-Reynolds-Number modification activated by IENUTA=6 .
PHOTON commands are supplied.
ENDDIS
PHOTON USE
p
phi
up z
gr ou x 1
msg contours of axial velocity
con w1 x 1 fi;0.001;pause;con off; red
msg contours of concentration of injected material
con a x 1 fi;0.001;pause;con off;red
msg enut contours
con enut x 1 fi;0.001;pause;con off;red
msg velocity vectors
vec x 1 sh;pause;con off;vec off;red
msg streamlines
stre 2d x 1 sh;int 20
enduse
GROUP 3. X-direction grid specification
** Activate polar coordinate system
CARTES=F; XULAST=0.01
GROUP 4. Y-direction grid specification
GRDPWR(Y,40,4.5*0.0254,1.0)
JETDIAM=0.2*YVLAST
GROUP 5. Z-direction grid specification
GRDPWR(Z,40,12.75*0.0254,1.0)
GROUP 7. Variables stored, solved & named
SOLVE(P1,V1,W1,C1); STORE(ENUT,LEN1); NAME(C1)=A
GROUP 9. Properties of the medium (or media)
RHO1=1.0; ENUL=1.E-5; PRNDTL(A)=0.7; PRT(A)=0.7
REYNO=WINJ*JETDIAM/ENUL
mesg(reynolds number is :reyno: if ok, press return
mesg(otherwise insert desired number
READVDU(REYNO,REAL,REYNO)
WINJ=REYNO*ENUL/JETDIAM
REYNO
DENRAT=RHOINJ/RHO1
mesg( Ratio of injected to surrounding density is :denrat:
mesg( If ok, press return, otherwise insert desired number...
READVDU(denrat,REAL,denrat)
RHOINJ=DENRAT*RHO1
DENRAT
ENUT=0.016*WINJ*JETDIAM
** settings for the Prandtl Mixing Length Model
EL1=MIXLENJET; ENUT=MIXLEN; DWDY=T
** EL1A = mixing-length constant for mixing-layer zone
EL1A=0.05
EL1B = '' '' '' for jet zone
EL1B=0.075
EL1C = velocity fraction for jet-width calculation
EL1C=0.01
EL1D = free-stream velocity for jet-width calculation
EL1D=0.0
EL1E = jet-discharge velocity ( mixing-length constant
is switched from EL1A to EL1B, when centre-line
velocity falls below EL1E )
EL1E=WINJ
** settings for the Local Reynolds Number Modification
IENUTA=6; ENUTA=0.2; ENUTB=4.0
GROUP 11. Initialization of variable or porosity fields
PATCH(INITIAL,INIVAL,1,1,1,NY/5,1,NZ,1,1)
COVAL(INITIAL,W1,0.0,WINJ); COVAL(INITIAL,A,0.0,1.0)
FIINIT(ENUT)= 0.016*WINJ*JETDIAM
GROUP 13. Boundary conditions and special sources
PATCH(IN,LOW,1,1,1,NY/5,1,1,1,1)
COVAL(IN,P1,FIXFLU,WINJ*RHO1); COVAL(IN,W1,ONLYMS,WINJ)
COVAL(IN,A,ONLYMS,1.0); COVAL(IN,V1,ONLYMS,0.0)
** the imposed velocity at the cylindrical wall
WALVEL=(0.32/8)*(winj*jetdiam/yvlast)*denrat**(-0.5)
PATCH(WALL,NORTH,1,1,NY,NY,1,NZ,1,1)
COVAL(WALL,P1,FIXFLU,RHO1*WALVEL); COVAL(WALL,W1,ONLYMS,0.0)
COVAL(WALL,A,ONLYMS,0.0)
PATCH(OUTLET,HIGH,1,1,1,4*NY/5,NZ,NZ,1,1)
COVAL(OUTLET,P1,1.E5,0.0); COVAL(OUTLET,A,ONLYMS,SAME)
COVAL(OUTLET,V1,ONLYMS,0.0); COVAL(OUTLET,W1,ONLYMS,0.0)
GROUP 15. Termination of sweeps
LSWEEP=100; SELREF=T; RESFAC=0.01
GROUP 17. Under-relaxation devices
RELAX(W1,FALSDT,0.001); RELAX(V1,FALSDT,0.1); RELAX(ENUT,LINRLX,0.5)
GROUP 22. Spot-value print-out
NPRMON=20; IYMON=5
GROUP 22. Spot-value print-out
IYMON=19; IZMON=10; TSTSWP=-1; itabl=1
GROUP 23. Field print-out and plot control
NYPRIN=NY/10; NZPRIN=NZ/10; NPLT=1
PATCH(EXIT,PROFIL,1,1,1,NY,NZ-1,NZ-1,1,1)
PLOT(EXIT,W1,0.0,0.0); PLOT(EXIT,A,0.0,0.0)
PATCH(PIPE,CONTUR,1,1,1,NY,1,NZ,1,1)
PLOT(PIPE,W1,0.0,10.0); PLOT(PIPE,A,0.0,10.0)
LIBREF=281
**END OF LIBRARY CASE 281