photon use p parphi gr ou x 1 msg volume fractions of hot fluid con br2 x 1 sh;0 1 100 pause con off;red msg contours of longitudinal velocity of cold fluid con sw1 x 1 z 1 5 sh;0 120 100 msg contours of longitudinal velocity of hot fluid con fw2 x 1 z 6 m sh;0 120 100 msg note the discontinuity pause con off;red msg contours of lateral velocity of cold fluid con cv1 x 1 y 1 12 sh;-10 40 100 msg contours of lateral velocity of hot fluid con dv2 x 1 y 13 m sh;-10 40 100 msg note the discontinuity pause con off;red msg contours of temperature of cold fluid con tmp1 x 1 y 1 12 sh;int 100 msg contours of temperature of hot fluid con tmp2 x 1 y 13 m sh;int 100 msg note the discontinuity pause con off;red se ve co u1 cv1 sw1 se ve re 200 msg vectors of cold-gas velocity vec x 1 y 1 13 sh se ve co u1 dv2 fw2 se ve re 200 msg vectors of cold-gas velocity vec x 1 y 13 m sh msg note the discontinuity pause msg contours of mass-transfer rate con mdot x 1 sh;int 100 msg msg Press e to END enduse ** L(W977) from the USER Input Library ****** TO LOAD CASE: TYPE L(W977) ****** GROUP 1. Run title and other preliminaries TEXT(Steady 2-fluid ducted flame; parab:W977 TITLE mesg(PC486/50 time last reported as 2.min DISPLAY The 1985-version of the two-fluid model of turbulence is here used for simulating turbulent combustion in gases. The diffusion flux is directly calculated from the normal-to-wall-velocities; an additional source for the normal-to-wall momentum equations, due to the mean-velocity gradient, is postulated. The flame spreads from a flame holder in a stream of pre-mixed combustible gas in a duct of constant cross-section. duct wall /////////////////////////////////////// -----------------------*--------------- /*****/ ----> /*****/ flame ------> inlet ** **/ exit -[*]--------------------------------------- flame holder axis Reference: Imperial College research of JZ Wu, 1985 ENDDIS * Fluid 1 is defined as hotter fluid and fluid 2 as colder one. * The flow is considered parabolic. * The system is two-dimensional. * The heat transfer to the duct wall neglected. * The densities of the two fluids are evaluated from the state equation of ideal gas. * The chemical reaction rate is expressed by an idealised single-step Arrhenius form. * It is assumed that only fluid 2 enters the duct at the inlet. This practice is to emphasise the role of inter- fluid transport of mass, momentum and energy. REAL(WIN,Cf,Cm,Cvw,Ct,Ch,Cr,WIDTH,LENGTH) **** Specifications **** LENGTH is the full length of the duct; WIDTH is the half width of the duct; WIN is the inlet velocity; WIDTH=0.0381;LENGTH=0.308;WIN=30.0 *** Model constants **** Cf=0.05;Cm=30.0;Cvw=1.0;Ch=10.0;Ct=1.0;Cr=3.5E3 GROUP 3. X-direction grid specification PARAB=T GROUP 4. Y-direction grid specification GRDPWR(Y,25,WIDTH,1.0) GROUP 5. Z-direction grid specification *** The length of duct is 1.0 GRDPWR(Z,35,LENGTH,1.0) GROUP 7. Variables stored, solved & named ONEPHS=F;SOLVE(P1,V1,V2,W1,W2,R1,R2,H1,H2) NAME(W1)=SW1;NAME(W2)=FW2;NAME(R1)=AR1 NAME(R2)=BR2;NAME(V1)=CV1;NAME(V2)=DV2;NAME(H1)=EH1 INTMDT=22;NAME(INTMDT)=MDOT;LEN1=23;NAME(LEN1)=LEN VIST=24;NAME(VIST)=VIS SOLUTN(MDOT,Y,N,N,N,N,N);SOLUTN(LEN,Y,N,N,N,N,N) SOLUTN(VIS,Y,N,N,N,N,N);STORE(TMP1,TMP2,DEN1,DEN2) GROUP 8. Terms (in differential equations) & devices TERMS(EH1,N,Y,Y,N,Y,Y);TERMS(H2,N,Y,Y,N,N,Y) DIFCUT=0.0 GROUP 9. Properties of the medium (or media) **** EL1=NIKURCH (GRND9) activates the GREX2 sequence for the length-scale of Nikuradse EL1=NIKURCH **** TMP=300.0+1500.0*H1(OR H2) TMP1=LINH;TMP1A=300.0;CP1=1./1500.0 TMP2=LINH;TMP2A=300.0;CP2=1./1500.0 *** RHO1=(P0+P1)*RHO1B/T1 RHO1=IDEALGAS;PRESS0=1.E5;RHO1B=3.3E-3;RHO2=IDEALGAS;RHO2B=3.3E-3 *** Turbulent-viscosity ENUT=2FLUID;ENUTA=Ct GROUP 10. Inter-phase-transfer processes and properties *** Inter-fluid friction CFIPS=GRND4;CFIPA=0.0;CFIPB=1.0;CFIPC=Cf;CFIPD=-1.0 *** Inter-fluid mass transfer CMDOT=GRND1;CMDTA=Cm;CMDTB=0.5;CMDTC=0.0 *** Inter-fluid heat transfer CINT(EH1)=Ch;CINT(H2)=Ch GROUP 11. Initialization of variable or porosity fields FIINIT(SW1)=WIN;FIINIT(FW2)=WIN;FIINIT(AR1)=0.5;FIINIT(BR2)=0.5 GROUP 13. Boundary conditions and special sources ****INLET INLET(INLET,LOW,1,1,1,NY,1,1,1,1) VALUE(INLET,P2,WIN);VALUE(INLET,FW2,WIN) ****Flame holder PATCH(HOLD,LOW,1,1,1,NY/10,1,1,1,1) COVAL(HOLD,EH1,FIXVAL,0.6);COVAL(HOLD,H2,FIXVAL,0.6) ****North-wall WALL (NORTHWAL,NORTH,1,1,NY,NY,1,NZ,1,1) COVAL(NORTHWAL,SW1,1.0,0.0);COVAL(NORTHWAL,FW2,1.0,0.0) ****Momentum source in the normal-to-wall-velocity equations PATCH(SHSO,CELL,1,1,1,NY,1,NZ,1,1) COVAL(SHSO,CV1,FIXFLU,GRND5);COVAL(SHSO,DV2,FIXFLU,GRND5);SHSOA=Cvw ***** Chemical reaction source **** PATCH(CHSO,VOLUME,1,1,1,NY,1,NZ,1,1) COVAL(CHSO,EH1,POLYNOM,1.0);COVAL(CHSO,H2,POLYNOM,1.0) CHSOA=Cr;CHSOB=5.0 GROUP 15. Termination of sweeps LITHYD=50 GROUP 17. Under-relaxation devices RELAX(P1,LINRLX,0.5);RELAX(AR1,LINRLX,0.1) RELAX(BR2,LINRLX,0.1);RELAX(CV1,FALSDT,1.E-4) RELAX(DV2,FALSDT,1.E-4);RELAX(SW1,FALSDT,1.E-4) RELAX(FW2,FALSDT,1.E-4);RELAX(MDOT,LINRLX,0.1) RELAX(EH1,FALSDT,1.E-4);RELAX(H2,FALSDT,1.E-4) GROUP 21. Print-out of variables NPRINT=LITHYD OUTPUT(AR1,N,N,N,N,N,N);OUTPUT(MDOT,Y,Y,Y,Y,Y,Y) PATCH(LPRO1,PROFIL,1,1,NY/2,NY/2,1,NZ,1,1) COVAL(LPRO1,P1,0.0,0.0) PATCH(WPRO,PROFIL,1,1,NY/2,NY/2,1,NZ,1,1) COVAL(WPRO,SW1,1.0,1.0);COVAL(WPRO,FW2,1.0,1.0) COVAL(WPRO,CV1,0.1,0.1);COVAL(WPRO,DV2,0.1,0.1) GROUP 22. Spot-value print-out IYMON=NY/2;IZMON=NZ/2;IPLTL=1000;TSTSWP=LITHYD/4 NPLT=2;NPRMON=100;NZPRIN=2;NYPRIN=2 GROUP 24. Dumps for restarts IDISPA=2;UWATCH=T;TSTSWP=-1