TEXT(Premixed 2Step CH4 Combustion TITLE DISPLAY The problem considered is turbulent reacting flow in a cylindrical combustion chamber with central and annular coaxial feed injectors supplying premixed methane and air. The geometry is axisymmetric with an outer radius of 0.2m and an axial length of 2m. The reactants are supplied at a temperature of 300K, and the composition of each inlet stream is identical. The default fuel/air equivalence ratio is 1.15, and the operating pressure is 1 bar. ENDDIS GROUP 1. Run title and other preliminaries REAL(WINF,WINO,KEL,EPL,KEINIT,TWAL,TEMFU,TEMOX) CHAR(ANS2);INTEGER(NYG);BOOLEAN(HSOLV,THRAD,BLOCK) REAL(RTUBE,ZLEN) REAL(YFU1IN,YOX1IN,YN21IN,YH2O1I,YCO21I) REAL(YFU2IN,YOX2IN,YN22IN,YH2O2I,YCO22I) HSOLV=T;THRAD=T WINF=115.0;WINO=10.0; RTUBE=0.2;ZLEN=2.743 TWAL=100.+273.;TEMFU=470.;TEMOX=503. MESG( porosity test ? (default=N) READVDU(ANS,CHAR,N) IF(:ANS:.EQ.Y) THEN + BLOCK=T + MESG( Porosities present ELSE + BLOCK=F + MESG( No porosities ENDIF ** fuel-rich stream YFU1IN=0.07;YOX1IN=0.1764;YH2O1I=0.02118;YCO21I=0.0263 YN21IN=1.-YFU1IN-YOX1IN-YH2O1I-YCO21I ** fuel-lean stream YFU2IN=0.0275;YOX2IN=0.1914;YH2O2I=0.01862;YCO22I=0.02353 YN22IN=1.-YFU2IN-YOX2IN-YH2O2I-YCO22I GROUP 2. Transience; time-step specification STEADY=T GROUP 3. X-direction grid specification CARTES=F;XULAST=0.1 GROUP 4. Y-direction grid specification NYG=8 IF(BLOCK) THEN + NREGY=5;NY=12 ELSE + NREGY=4;NY=8 ENDIF IREGY=1;GRDPWR(Y,2,0.0191,1.0);IREGY=2;GRDPWR(Y,2,0.0286,1.0) IREGY=3;GRDPWR(Y,2,0.0548,1.0);IREGY=4;GRDPWR(Y,2,0.1048,1.0) IF(BLOCK) THEN + IREGY=5;GRDPWR(Y,4,0.1048,1.0) ENDIF GROUP 5. Z-direction grid specification NREGZ=2;NZ=10 IREGZ=1;GRDPWR(Z,4,0.381,1.0);IREGZ=2;GRDPWR(Z,6,2.362,1.3) GROUP 6. Body-fitting and other grid distortions. MESG( BFC test ? (default=N) READVDU(ANS,CHAR,N) IF(:ANS2:.EQ.Y) THEN + BFC=T;NONORT=T + MESG( BFCs present ELSE + BFC=F + MESG( No BFCs ENDIF IF(BLOCK) THEN + CONPOR(BLK1,0.0,CELL,1,NX,NYG+1,NY,1,NZ) + OUTPUT(VPOR,P,P,Y,P,P,P) ENDIF GROUP 7. Variables stored, solved & named SOLVE(P1,V1,W1);STORE(VIST,DEN1,TMP1,SPH1,YSUM) SOLUTN(P1,P,P,Y,P,P,P);SOLUTN(V1,P,P,P,P,P,N) SOLUTN(W1,P,P,P,P,P,N);TURMOD(KEMODL) IF(HSOLV) THEN + SOLVE(H1);TERMS(H1,N,P,P,P,P,P) + SOLUTN(H1,P,P,Y,P,P,P) ELSE + STORE(H1) ENDIF IF(THRAD) THEN + REAL(ABSORB,SCAT,SIGMA,EMPW,EMISW,EMISG,EMPG) + ABSORB=1.45;SCAT=0.; EMISG=0.07 + SIGMA=5.6697E-8; EMISW=1.0 + EMPW=SIGMA*TWAL**4; EMPG=SIGMA*EMISG + RADIAT(RADI,ABSORB,SCAT,H1) + SOLUTN(H1,P,P,Y,P,P,P);SOLUTN(SRAD,P,P,Y,P,P,P) ENDIF GROUP 8. Terms (in differential equations) & devices GROUP 9. Properties of the medium (or media). ENUL=4.2E-5 *** START OF EXTENDED SCRS MODEL SETTINGS PRESS0=1.0000E+05 INTEGER(NSPEC,NELEM);NSPEC=7;NELEM=4 INTEGER(NCSTEP,NCREAC);NCSTEP=2;NCREAC=3 SCRS(SYSTEM,NCSTEP,NCREAC,NELEM,FRATE) SCRS(SPECIES,CH4,O2,H2,CO,H2O,CO2,N2) STORE(P1RS,S1RS,S2RS,MMWT,ELC,ELN,ELO,ELH) ** Define fuel & oxidiser composition & temperatures SCRS(FUIN,YFU1IN,YOX1IN,0.0,0.0,YH2O1I,YCO21I,YN21IN,TEMFU) SCRS(OXIN,YFU2IN,YOX2IN,0.0,0.0,YH2O2I,YCO22I,YN22IN,TEMOX) SCRS(PROP,CHEMKIN,SCRS) MESG(2 step 3 reactions finite-rate EBU model MESG(2CH4 + O2 > 2CO + 4H2 MESG(2CO + O2 > 2CO2 MESG(2H2 + O2 > 2H2O *** END OF EXTENDED SCRS MODEL SETTINGS GROUP 11. Initialization of variable or porosity fields INIADD=F; FIINIT(W1)=20. KEINIT=((2.E-2*5.)**2)/2.; FIINIT(EP)=65.*(KEINIT**1.5) IF(THRAD) THEN + REAL(TGUESS);TGUESS=500. + FIINIT(SRAD)=0.07*SIGMA*TGUESS**4 ENDIF IF(HSOLV) THEN + FIINIT(H1)=-1.39E5 ENDIF FIINIT(KE)=KEINIT; FIINIT(CH4)=YFU1IN GROUP 13. Boundary conditions and special sources * INLET boundary condition for centre burner KEL=0.5*(0.2*27.18)**2; EPL=1.643*((KEL)**1.5)/0.0095 INLET(SCRSF,LOW,1,NX,#2,#2,1,1,#1,#NREGT) VALUE(SCRSF,EP,EPL); VALUE(SCRSF,KE,KEL) VALUE(SCRSF,F,1.); VALUE(SCRSF,CH4,YFU1IN) IF(HSOLV) THEN + VALUE(SCRSF,H1,GRND3) ENDIF IF(BFC) THEN + VALUE(SCRSF,P1,GRND3) + VALUE(SCRSF,V1,GRND3); VALUE(SCRSF,W1,GRND3) + VALUE(SCRSF,VCRT,ZERO); VALUE(SCRSF,WCRT,115.0) ELSE + VALUE(SCRSF,P1,GRND1); VALUE(SCRSF,W1,115.0) ENDIF * INLET boundary condition, name OUTER "Oxidiser" BURNER KEL=0.5*(0.2*6.18)**2; EPL=1.643*((KEL)**1.5)/0.05 INLET(SCRSO,LOW,1,NX,#4,#4,1,1,#1,#NREGT) VALUE(SCRSO,P1,GRND3) VALUE(SCRSO,EP,EPL); VALUE(SCRSO,KE,KEL) VALUE(SCRSO,F,0.); VALUE(SCRSO,CH4,YFU2IN) IF(HSOLV) THEN + VALUE(SCRSO,H1,GRND3) ENDIF IF(BFC) THEN + VALUE(SCRSO,P1,GRND3) + VALUE(SCRSO,V1,GRND3); VALUE(SCRSO,W1,GRND3) + VALUE(SCRSO,VCRT,ZERO); VALUE(SCRSO,WCRT,10.0) ELSE + VALUE(SCRSO,P1,GRND1); VALUE(SCRSO,W1,10.0) ENDIF * OUTLET boundary condition, name OUT PATCH(OUT,HIGH,1,NX,1,NYG,#NREGZ,#NREGZ,#1,#NREGT) COVAL(OUT,P1,10.0,0.);COVAL(OUT,F,ONLYMS,SAME) IF(HSOLV) THEN + COVAL(OUT,H1,ONLYMS,SAME) ENDIF * WALL boundary condition, name WALL3 PATCH(NWALL3,NWALL,1,NX,NYG,NYG,1,NZ,#1,#NREGT) COVAL(NWALL3,W1,GRND2,0.0) COVAL(NWALL3,KE,GRND2,GRND2);COVAL(NWALL3,EP,GRND2,GRND2) IF(THRAD) THEN + PATCH(NWALL3R,NORTH,1,NX,NYG,NYG,1,NZ,#1,#NREGT) + COVAL(NWALL3R,SRAD,EMISW/(2.0-EMISW),EMPW) ENDIF GROUP 15. Termination of sweeps LSWEEP=250 GROUP 16. Termination of iterations GROUP 17. Under-relaxation devices RELAX(P1,LINRLX,1.0); RELAX(V1,FALSDT,5.E-3) RELAX(W1,FALSDT,5.E-3); RELAX(KE,FALSDT,5.E-3) RELAX(EP,FALSDT,5.E-3); RELAX(DEN1,LINRLX,0.5) RELAX(F,LINRLX,0.8) RELAX(CH4,FALSDT,1.E-3); RELAX(CO,FALSDT,1.E-3) RELAX(H2,FALSDT,1.E-3) IF(HSOLV) THEN + RELAX(H1,FALSDT,1.0) ENDIF IF(THRAD) THEN + RELAX(SRAD,FALSDT,1.0) ENDIF GROUP 18. Limits on variables or increments to them VARMIN(TMP1)=1.E-10; VARMIN(DEN1)=1.E-10 OUTPUT(TMP1,P,P,P,P,Y,Y); OUTPUT(DEN1,P,P,P,P,Y,Y) GROUP 20. Preliminary print-out ECHO=T GROUP 21. Print-out of variables TSTSWP=-1 GROUP 22. Spot-value print-out IXMON=1;IYMON=NYG/2;IZMON=6 GROUP 23. Field print-out and plot control ITABL=3;NPLT=10;NYPRIN=1 GROUP 24. Dumps for restarts