PHOTON USE p msg Pressafter each pause gr ou x 1 msg first-fluid velocity components set vec com u1 cv1 sw1 vec x 1 sh pause vec off red msg second-fluid velocity components set vec com 2u dv2 fw2 vec x 1 sh pause;vec off;red msg first-fluid concentration contours con ar1 x 1 fi;0.01 pause msg second-fluid concentration contours con br2 x 1 fi;0.01 msg - msg Press e to END enduse based on case 976, concerns 2-fluid mixing in a duct dbs summer 1991 GROUP 1. Run title and other preliminaries TEXT(Mixing in a duct; Two-Fluid Model :W974 TITLE mesg(PC486/50 time last reported as 5.5 min DISPLAY TWO-FLUID MODEL OF JETS MIXING IN A DUCT 2-dimensional (y-z), Cartesian, steady, two-phase, elliptic This is an example of the application of the two-fluid model of turbulence to non-reacting, turbulent flow in a duct, as illustrated: //////////////////////////////////////////////// Inlet Exit --------> W2 ----------> //////////// ----------> -------> ///////////////////////////////////// In the present calculations, the fluid 1 is defined as that which moves away from the stepped wall and fluid 2 as that moves towards it respectively. It is postulated that only fluid 2 enters the duct at the inlet, and that it is converted into fluid 1 there by entrainment. The boundary condition employed here is an extreme one to emphasise the role of inter-fluid transport of mass and momentum. enddis INTEGER(NYS,NZS) REAL(WIN,HIGHT,WIDTH,Cf,Cm,Cvw,Ct) WIN=18.2;HIGHT=0.0381;WIDTH=HIGHT*3.0;NYS=15;NZS=6 **** Model constants **** Cf=0.05;Cm=10.0;Cvw=1.0;Ct=1.0 GROUP 4. Y-direction grid specification *** The width of duct is 0.1143 NY=30;YVLAST=WIDTH YFRAC(1)=-15.0;YFRAC(2)=0.022225 YFRAC(3)=15.0;YFRAC(4)=0.044446 GROUP 5. Z-direction grid specification *** The length of duct is 0.762 NZ=30;ZWLAST=1.0 ZFRAC(1)=-30.0;ZFRAC(2)=2.54E-2 GROUP 7. Variables stored, solved & named ONEPHS=F SOLVE(P1,V1,V2,W1,W2,R1,R2);SOLUTN(P1,Y,Y,Y,N,N,N) SOLVE(U1,U2);NAME(U2)=2U NAME(W1)=SW1;NAME(W2)=FW2;NAME(R1)=AR1;NAME(R2)=BR2 NAME(V1)=CV1;NAME(V2)=DV2 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) GROUP 9. Properties of the medium (or media) EL1=NIKURCH;RHO1=0.1;RHO2=1.0;ENUL=1.E-6;ENUT=2FLUID;ENUTA=Ct GROUP 10. Inter-phase-transfer processes and properties *** Ierter-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 GROUP 11. Initialization of variable or porosity fields FIINIT(SW1)=WIN;FIINIT(FW2)=WIN;FIINIT(AR1)=0.5;FIINIT(BR2)=0.5 CONPOR(0.0,CELL,1,1,1,-NYS,1,-NZS) GROUP 13. Boundary conditions and special sources *** Inlet INLET(INLET,LOW,1,1,NYS+1,NY,1,1,1,1) VALUE(INLET,P2,WIN*0.99);VALUE(INLET,FW2,WIN) VALUE(INLET,P1,WIN*0.01);VALUE(INLET,SW1,WIN) *** Exit PATCH(OUTLET,HIGH,1,1,1,NY,NZ,NZ,1,1) COVAL(OUTLET,P1,1.E5,0.0);COVAL(OUTLET,P2,1.E5,0.0) COVAL(OUTLET,CV1,ONLYMS,0.0);COVAL(OUTLET,DV2,ONLYMS,0.0) COVAL(OUTLET,SW1,ONLYMS,0.0);COVAL(OUTLET,FW2,ONLYMS,0.0) *** 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) *** South-wall WALL (SOUTHWAL,SOUTH,1,1,1,1,NZS+1,NZ,1,1) COVAL(SOUTHWAL,SW1,1.0,0.0);COVAL(SOUTHWAL,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 *** Source of fluid 1 at face of step PATCH(STEPIN,HIGH,1,1,1,NYS,NZS+1,NZS+1,1,1) COVAL(STEPIN,P1,FIXFLU,0.99*0.5*WIN) COVAL(STEPIN,P2,FIXFLU,0.01*0.5*WIN) COVAL(STEPIN,U1,ONLYMS,WIN);COVAL(STEPIN,2U,ONLYMS,WIN) GROUP 15. Termination of sweeps LSWEEP=75;SELREF=T; RESFAC=1.E-2 GROUP 17. Under-relaxation devices RELAX(P1,LINRLX,1.0);RELAX(AR1,LINRLX,0.25) RELAX(BR2,LINRLX,0.25);RELAX(CV1,FALSDT,0.0001) RELAX(DV2,FALSDT,0.0001);RELAX(SW1,FALSDT,0.001) RELAX(FW2,FALSDT,0.001);RELAX(MDOT,LINRLX,0.5) GROUP 21. Print-out of variables OUTPUT(AR1,N,N,N,N,N,N);OUTPUT(MDOT,Y,Y,Y,Y,Y,Y) PATCH(LPRO1,PROFIL,1,1,1,1,NZS,NZ,1,1) COVAL(LPRO1,P1,0.0,0.0) PATCH(LPRO2,PROFIL,1,1,NY,NY,NZS,NZ,1,1) COVAL(LPRO2,P1,0.0,0.0) PATCH(WPRO,PROFIL,1,1,1,NY,8,8,1,1) 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) PATCH(MAP,CONTUR,1,NX,1,NY,1,NZ,1,LSTEP) PLOT(MAP,AR1,0.0,10.0);PLOT(MAP,SW1,0.0,10.0) PLOT(MAP,U1,0.0,0.0) GROUP 22. Spot-value print-out IYMON=NYS-2;IZMON=NZS+2 NPLT=1;NYPRIN=NY/5;NZPRIN=NZ/5;ITABL=1;TSTSWP=-1