PHOTON USE
p;parphi
5 1
;;;;
up z
msg pressures
con p1 x 1 fi;0.001;pause;con off;red
msg phase-1 vol fract
con r1 x 1 fi;0.001;pause;con off;red
msg phase-1 radial vel.
con v1 x 1 fi;0.001;pause;con off;red
msg phase-2 radial vel.
con v2 x 1 fi;0.001;pause;con off;red
msg phase-1 axial vel.
con w1 x 1 fi;0.001;pause;con off;red
msg phase-2 axial vel.
con w2 x 1 fi;0.001;pause;con off;red
ENDUSE
#cls
TEXT(2-PHASE BUBBLY AIR/WATER PIPE FLOW
TITLE
DISPLAY
The case considered is 2-phase turbulent air-water flow in a
pipe, as studied experimentally by Seriwaza et al [1992] for
upward flow and by Lahey et al [1992] for both upward and
downward flow.
The input file is set up to run any one of these three cases.
Each calculation is performed with the parabolic option, and,
for testing purposes the calculation is terminated 5 diameters
downstream.
However, for comparison with data the calculation should be
continued to 35 diameters downstream, which corresponds to the
experimental measuring station.
The 2-phase model accounts for interfacial drag, lift, pressure
and virtual-mass forces.
#pause
The standard k-e model is employed with the option to select one
of two modifications to account for bubble-induced turbulence.
For upward flow, the predicted and measured void-fraction
profiles show that the gas is taken away from the centre and
towards the walls, while for downward flow the reverse is
observed.
For upward flow the predictions are in reasonable agreement with
the data, but much less so for downward flow. However, the
influences of mesh size, the interfacial-modelling coefficients
and the turbulence-modelling modifications need to be investigated.
For the results of a study made with a 1995 version of
PHOENICS, click
here.
ENDDIS
#pause
INTEGER(JRUN,KMOD)
MESG( Select the required test case:
MESG( The options are:
MESG( 1 - Seriwaza upflow data (default)
MESG( 2 - Lahey upflow data
MESG( 3 - Lahey downflow data
MESG(
READVDU(JRUN,INT,1)
REAL(RHOL,RHOG,EMULIQ,EMUGAS,RGAS,RLIQ,VSGAS,VSLIQ,TKEIN,EPSIN)
REAL(VSTOT,VIN1,VIN2,RIN1,RIN2,FLOWL,FLOWG,PI,XGAS,XLIQ,FRIC)
REAL(VGAS,VLIQ,DIAM,GRAD,PLEN,DIAMB,EMUMIX,REYMIX,GRAVAC)
RHOL=1000.;EMUGAS=1.8E-5;PI=3.14159
**VSGAS & VSLIQ are superficial velocities
**Upflow data of Seriwaza et al, 'Phase distribution in bubbly
flow', In Multiphase Science & Technology, Vol.6, p257-301,
Ed. G.F.Hewitt, J.M.Delhaye, & N.Zuber, Hemisphere Publ.
Corp [1992].
IF(JRUN.EQ.1) THEN
+ MESG(Seriwaza upflow data
+ VSGAS=0.077;VSLIQ=1.36;GRAVAC=-9.81;DIAM=0.06;EMULIQ=1.E-3
+ RHOG=1.34
ENDIF
**Upflow data of Lahey et al, 'Phase distribution and 2-phase
flow', In Multiphase Science & Technology, Vol.6, p303-349,
Ed. G.F.Hewitt, J.M.Delhaye, & N.Zuber, Hemisphere Publ.
Corp [1992].
IF(JRUN.EQ.1) THEN
+ TEXT(BUBBLY AIR/WATER PIPE- Seriwaza upflow
ENDIF
IF(JRUN.EQ.2) THEN
+ MESG(Lahey upflow data
+ VSGAS=0.1;VSLIQ=1.08;GRAVAC=-9.81;DIAM=0.057;EMULIQ=1.207E-3
+ RHOG=1.24
+ TEXT(BUBBLY AIR/WATER PIPE- Lahey upflow
ENDIF
**Downflow data of Lahey et al [1992].]
IF(JRUN.EQ.3) THEN
+ MESG(Lahey downflow data
*** Downflow data of Wang et al [1992]
+ VSGAS=0.1;VSLIQ=1.08;GRAVAC=9.81;DIAM=0.057;EMULIQ=1.207E-3
+ RHOG=1.24
+ TEXT(BUBBLY AIR/WATER PIPE- Lahey downflow
ENDIF
VSTOT=VSGAS+VSLIQ
*** compute inlet void fractions presuming no slip at inlet
RGAS=VSGAS/VSTOT;RLIQ=1.-RGAS
*** compute inlet phase velocities
VGAS=VSGAS/RGAS;VLIQ=VSLIQ/RLIQ
*** specify pipe radius & length
GRAD=0.5*DIAM;PLEN=35.*DIAM
*** specify mean bubble diameter
DIAMB=3.E-3
GROUP 1. Run title and other preliminaries
GROUP 2. Transience; time-step specification
PARAB=T
GROUP 3. X-direction grid specification
CARTES=F;XULAST=0.1;NX=1
GROUP 4. Y-direction grid specification
GRDPWR(Y,30,GRAD,1.0)
GROUP 5. Z-direction grid specification
*** specify uniform step-size of 0.1*DIAM
NZ=50
NZ=350
GRDPWR(Z,NZ,NZ*PLEN/350,1.0)
GROUP 6. Body-fitted coordinates or grid distortion
GROUP 7. Variables stored, solved & named
ONEPHS=F;SOLVE(P1,V1,V2,W1,W2,R1,R2)
TURMOD(KEMODL);STORE(ENUT);STORE(CD,REYN)
MESG( Enter the required k-e turbulence modification:
MESG( 1 - No modifications (default)
MESG( 2 - Additional KE & EP sources due to bubbles
MESG( 3 - Enhanced ENUT due to bubbles
MESG(
READVDU(KMOD,INT,1)
GROUP 8. Terms (in differential equations) & devices
GROUP 9. Properties of the medium (or media)
RHO1=RHOL;RHO2=RHOG;VIN1=VLIQ;VIN2=VGAS;RIN1=RLIQ;RIN2=RGAS
FLOWL=RHO1*RIN1*VIN1;FLOWG=RHO2*RIN2*VIN2;ENUL=EMULIQ/RHOL
** estimate Reynolds number
XGAS=FLOWG/(FLOWL+FLOWG);XLIQ=1.-XGAS
EMUMIX=1.0/(XGAS/EMUGAS+XLIQ/EMULIQ)
REYMIX=(FLOWL+FLOWG)*DIAM/EMUMIX;FRIC=0.3164/REYMIX**0.25
TKEIN=FRIC*VIN1*VIN1/8.;EPSIN=0.1643*TKEIN**1.5/(0.1*GRAD)
FIINIT(KE)=TKEIN;FIINIT(EP)=EPSIN
GROUP 10. Inter-phase-transfer processes and properties
*** select dirty-water spherical bubble drag correlation
CFIPS=GRND7;CFIPD=5.0;CFIPA=1.E-3;RLOLIM=1.E-3;CFIPB=DIAMB
*** select interfacial lift, virtual-mass & pressure forces
CLIFT=GRND2;CVM=GRND2;CVMA=0.5;CPIP=GRND2;CPIPA=0.25;CLIFTA=0.075
STORE(VMSW,VMSV)
IF(JRUN.EQ.3) THEN
+ CPIPA=0.1
ENDIF
INTSOR(LIFT,CLIFT,CLIFTA,RELAX,0.1)
INTSOR(INTPL,CPIP,CPIPA)
GROUP 11. Initialization of variable or porosity fields
FIINIT(W1)=VIN1;FIINIT(W2)=VIN2;FIINIT(R1)=RIN1;FIINIT(R2)=RIN2
GROUP 12. Unused
GROUP 13. Boundary conditions and special sources
** inlet boundary
INLET(IN,LOW,1,NX,1,NY,1,1,1,1)
VALUE(IN,P1,FLOWL);VALUE(IN,W1,VIN1)
VALUE(IN,P2,FLOWG);VALUE(IN,W2,VIN2)
VALUE(IN,KE,TKEIN);VALUE(IN,EP,EPSIN)
** gravity
PATCH(GRAVITY,PHASEM,1,NX,1,NY,1,NZ,1,1)
COVAL(GRAVITY,W2,FIXFLU,GRAVAC*(1.-RHOL/RHOG))
** wall boundary
WALL(NWALL,NORTH,1,NX,NY,NY,1,NZ,1,1)
** Bubble-induced turbulence production
IF(KMOD.EQ.2) THEN
+ EL1A=0.1;PATCH(KEDI,CELL,1,NX,1,NY,1,NZ,1,LSTEP)
+ COVAL(KEDI,KE,FIXFLU,GRND3);COVAL(KEDI,EP,FIXFLU,GRND3)
ENDIF
IF(KMOD.EQ.3) THEN
+ ENUTB=1.0;ENUTC=0.3;KELIN=3
ENDIF
GROUP 15. Termination of sweeps
** deactivate selref as unreliable in V3.1
LITHYD=40;SELREF=F;RESFAC=0.01
GROUP 16. Termination of iterations
GROUP 17. Under-relaxation devices
REAL(DTF);DTF=0.1*YVLAST/VLIQ
dtf=dtf*0.1
RELAX(V1,FALSDT,0.01*DTF);RELAX(V2,FALSDT,0.01*DTF)
RELAX(W1,FALSDT,DTF);RELAX(W2,FALSDT,DTF)
RELAX(R1,LINRLX,0.3);RELAX(R2,LINRLX,0.3)
RELAX(KE,LINRLX,0.3);RELAX(EP,LINRLX,0.3)
GROUP 18. Limits on variables or increments to them
VARMAX(W1)=10.0
VARMIN(W1)=1.E-10;VARMIN(W2)=1.E-10
VARMIN(R1)=1.E-10;VARMIN(R2)=1.E-10
GROUP 21. Print-out of variables
NZPRIN=NZ/5
GROUP 22. Spot-value print-out
IYMON=NY-2;TSTSWP=LITHYD;NPLT=2;IDISPA=50
GROUP 23. Field print-out and plot control
OUTPUT(LISV,Y,N,Y,Y,Y,Y);OUTPUT(LISW,Y,N,Y,Y,Y,Y)
OUTPUT(VMSW,Y,N,Y,Y,Y,Y);OUTPUT(VMSV,Y,N,Y,Y,Y,Y)
tstswp=-1
GROUP 24. Dumps for restarts
libref=218
idispa=1
#maxabs
#endpause
isg51=2