TALK=T;RUN(1,1) DISPLAY MONO-PROPELLANT ROCKET COMBUSTION 2-dimensional (x-y), Cartesian, steady, two-phase, elliptic simulation The problem considered is that of the injection of monopropellant droplets through small holes in one end of a rocket motor. These droplets burn (i.e undergo a phase change involving the disappearance of high-density liquid and its replacement by low- density gas), at a rate dependent upon the droplet diameter. As a consequence, a pressure gradient is set up which accelerates the gas and, to a lesser extent, the liquid. Friction between the droplets and the gas causes the former at first to deccelerate and later to accelerate. The model is highly idealised, and does not represent any particular motor or propellant. You will have an opportunity to vary the interphase-friction coefficient and the injection velocity of the liquid. enddis PHOTON USE p phi gr ou z 1 set vec comp au1 cv1 - msg Gas-velocity vectors vec z 1 sh msg Pressto continue pause vec off;red set vec comp bu2 dv2 - msg Droplet-velocity vectors vec z 1 sh msg Press to continue pause vec off;red msg volume fraction of liquid con liq z 1 sh;int 50 msg Press to continue pause msg Note that the grid is very coarse gr z 1 msg Press e to END enduse DISPLAY The problem considered is that of the injection of monopropellant droplets through small holes in one end of a rocket motor. These droplets burn (i.e undergo a phase change involving the dis- appearance of high-density liquid and its replacement by low- density gas), at a rate dependent upon the droplet diameter. As a consequence, a pressure gradient is set up which accelerates the gas and, to a lesser extent, the liquid. Friction between the droplets and the gas causes the former at first to deccelerate and later a accelerate. The main task is to compute the distance from the injector at which the propellant is fully consumed, as functions: of the injection velocity, of the propellant and combustion-product properties, and of a measure of the relative speed of momentum and heat transfer. The GX-subroutine GXDROP is used for this case. ENDDIS ************************************************************ Group 1. Run Title and Number ************************************************************ ************************************************************ TEXT(Rock2; 2D MONOPROPELLANT ROCKET :W971 ) ************************************************************ ************************************************************ IRUNN = 1 ;LIBREF = 14 ************************************************************ Group 2. Time dependence STEADY = T ************************************************************ Group 3. X-Direction Grid Spacing CARTES = T NX = 10 XULAST =1. XFRAC(1)=0.1 ;XFRAC(2)=0.2 XFRAC(3)=0.3 ;XFRAC(4)=0.4 XFRAC(5)=0.5 ;XFRAC(6)=0.6 XFRAC(7)=0.7 ;XFRAC(8)=0.8 XFRAC(9)=0.9 ;XFRAC(10)=1. ************************************************************ Group 4. Y-Direction Grid Spacing NY = 10 YVLAST =0.5 YFRAC(1)=0.1 ;YFRAC(2)=0.2 YFRAC(3)=0.3 ;YFRAC(4)=0.4 YFRAC(5)=0.5 ;YFRAC(6)=0.6 YFRAC(7)=0.7 ;YFRAC(8)=0.8 YFRAC(9)=0.9 ;YFRAC(10)=1. ************************************************************ Group 5. Z-Direction Grid Spacing PARAB = F NZ = 1 ZWLAST =1. ZFRAC(1)=1. ************************************************************ Group 6. Body-Fitted Coordinates ************************************************************ Group 7. Variables: STOREd,SOLVEd,NAMEd ONEPHS = F EQUVEL = F NAME(1)=P1 ;NAME(3)=AU1 NAME(4)=BU2 ;NAME(5)=CV1 NAME(6)=DV2 ;NAME(9)=GAS NAME(10)=LIQ ;NAME(11)=SHAD NAME(149)=CFIP ;NAME(150)=MDOT * Y in SOLUTN argument list denotes: * 1-stored 2-solved 3-whole-field * 4-point-by-point 5-explicit 6-harmonic averaging SOLUTN(P1,Y,Y,N,N,N,Y) SOLUTN(AU1,Y,Y,N,N,N,Y) SOLUTN(BU2,Y,Y,N,N,N,Y) SOLUTN(CV1,Y,Y,N,N,N,Y) SOLUTN(DV2,Y,Y,N,N,N,Y) SOLUTN(LIQ,Y,Y,N,N,N,Y) SOLUTN(SHAD,Y,Y,N,N,N,Y) SOLUTN(CFIP,Y,N,N,N,N,Y) SOLUTN(MDOT,Y,N,N,N,N,Y) INTMDT = 150 ************************************************************ Group 8. Terms & Devices * Y in TERMS argument list denotes: * 1-built-in source 2-convection 3-diffusion 4-transient * 5-first phase variable 6-interphase transport TERMS(P1,Y,Y,Y,N,Y,Y) TERMS(AU1,Y,Y,N,Y,Y,Y) TERMS(BU2,Y,Y,N,Y,N,Y) TERMS(CV1,Y,Y,Y,Y,Y,Y) TERMS(DV2,Y,Y,Y,Y,N,Y) TERMS(LIQ,Y,Y,N,Y,N,Y) TERMS(SHAD,Y,Y,N,Y,N,Y) DIFCUT =0.5 ;ZDIFAC =1. GALA = F ;ADDDIF = F EQDVDP = F ISOLX = -1 ;ISOLY = -1 ;ISOLZ = -1 ************************************************************ Group 9. Properties used if PRPS is not stored, and where PRPS = -1.0 if it is! RHO1 =10. ;TMP1 =0. EL1 =0. TSURR =0. ;TEMP0 =0. PRESS0 =1.0E+07 DVO1DT =0. ;DRH1DP =0. EMISS =0. ;SCATT =0. RADIA =0. ;RADIB =0. RHO2 =1.0E+04 ;TMP2 =0. EL2 =0. DVO2DT =0. ;DRH2DP =0. ENUL =1.0E-05 ;ENUT =0. PHINT(AU1)=-2.022E+04 ;PHINT(BU2)=-2.022E+04 PHINT(CV1)=-2.022E+04 ;PHINT(DV2)=-2.022E+04 PHINT(LIQ)=-2.022E+04 ;PHINT(SHAD)=-2.022E+04 PRNDTL(CV1)=1. ;PRNDTL(DV2)=1. PRT(CV1)=1. ;PRT(DV2)=1. CP1 =1. ;CP2 =1. ************************************************************ Group 10.Inter-Phase Transfer Processes CFIPS = GRND1 RLOLIM =1.0E-09 ;CMDOT =1. CFIPA =0. ;CFIPB =0. CFIPC =1.0E+05 ;CFIPD =0. CINT(P1)=1. ;CINT(AU1)=1. CINT(BU2)=1. ;CINT(CV1)=1. CINT(DV2)=1. ;CINT(LIQ)=1. CINT(SHAD)=1. PHINT(P1)=-2.022E+04 ;PHINT(AU1)=-2.022E+04 PHINT(BU2)=-2.022E+04 ;PHINT(CV1)=-2.022E+04 PHINT(DV2)=-2.022E+04 ;PHINT(LIQ)=-2.022E+04 PHINT(SHAD)=-2.022E+04 ************************************************************ Group 11.Initial field variables (PHIs) FIINIT(P1)=1.0E-10 ;FIINIT(AU1)=50. FIINIT(BU2)=50. ;FIINIT(CV1)=1.0E-10 FIINIT(DV2)=1.0E-10 ;FIINIT(GAS)=0.999 FIINIT(LIQ)=1.0E-03 ;FIINIT(SHAD)=1.0E-03 FIINIT(CFIP)=1.0E-10 ;FIINIT(MDOT)=10. No PATCHes yet used for this Group INIADD = F FSWEEP = 1 NAMFI =CHAM ************************************************************ Group 12. Patchwise adjustment of terms Patches for this group are printed with those for Group 13. Their names begin either with GP12 or & ************************************************************ Group 13. Boundary & Special Sources PATCH(INLET ,WEST , 1, 1, 1, 5, 1, 1, 1, 1) COVAL(INLET ,AU1 ,0. ,0. ) COVAL(INLET ,BU2 ,0. ,50. ) COVAL(INLET ,CV1 ,0. ,0. ) COVAL(INLET ,DV2 ,0. ,0. ) COVAL(INLET ,GAS , FIXFLU ,0. ) COVAL(INLET ,LIQ , FIXFLU ,2000. ) PATCH(OUTLET ,CELL , 10, 10, 1, 5, 1, 1, 1, 1) COVAL(OUTLET ,AU1 ,0. ,0. ) COVAL(OUTLET ,BU2 ,0. ,0. ) COVAL(OUTLET ,GAS ,1. ,0. ) COVAL(OUTLET ,LIQ ,1000. ,0. ) XCYCLE = F EGWF = T WALLCO = GRND2 ************************************************************ Group 14. Downstream Pressure For PARAB ************************************************************ Group 15. Terminate Sweeps LSWEEP = 200 ;ISWC1 = 1 LITHYD = 1 ;LITFLX = 1 ;LITC = 1 ;ITHC1 = 1 ISWR1 = 1 ;ISWR2 = 10000 SELREF = T RESFAC =1.0E-02 ************************************************************ Group 16. Terminate Iterations LITER(P1)=20 ;LITER(AU1)=10 LITER(BU2)=10 ;LITER(CV1)=10 LITER(DV2)=10 ;LITER(LIQ)=1 LITER(SHAD)=1 ENDIT(P1)=1.0E-03 ;ENDIT(AU1)=1.0E-03 ENDIT(BU2)=1.0E-03 ;ENDIT(CV1)=1.0E-03 ENDIT(DV2)=1.0E-03 ;ENDIT(LIQ)=1.0E-03 ENDIT(SHAD)=1.0E-03 ************************************************************ Group 17. Relaxation RELAX(P1,LINRLX,1.) RELAX(AU1,FALSDT,0.02) RELAX(BU2,FALSDT,0.02) RELAX(CV1,FALSDT,2.0E-03) RELAX(DV2,FALSDT,2.0E-03) RELAX(GAS,LINRLX,1.) RELAX(LIQ,LINRLX,0.2) RELAX(SHAD,LINRLX,0.6) RELAX(CFIP,LINRLX,1.) RELAX(MDOT,LINRLX,1.) OVRRLX =0. EXPERT = F ;NNORSL = F ************************************************************ Group 18. Limits VARMAX(P1)=1.0E+10 ;VARMIN(P1)=-1.0E+10 VARMAX(AU1)=1.0E+06 ;VARMIN(AU1)=-1.0E+06 VARMAX(BU2)=1.0E+06 ;VARMIN(BU2)=-1.0E+06 VARMAX(CV1)=1.0E+06 ;VARMIN(CV1)=-1.0E+06 VARMAX(DV2)=1.0E+06 ;VARMIN(DV2)=-1.0E+06 VARMAX(GAS)=1. ;VARMIN(GAS)=1.0E-06 VARMAX(LIQ)=1.0E-03 ;VARMIN(LIQ)=1.0E-09 VARMAX(SHAD)=1. ;VARMIN(SHAD)=1.0E-06 VARMAX(CFIP)=1.0E+10 ;VARMIN(CFIP)=-1.0E+10 VARMAX(MDOT)=1.0E+10 ;VARMIN(MDOT)=-1.0E+10 ************************************************************ Group 19. Data transmitted to GROUND PRTSIZ = T PARSOL = F ISG62 = 1 ************************************************************ Group 20. Preliminary Printout ************************************************************ Group 21. Print-out of Variables INIFLD = F ;SUBWGR = F * Y in OUTPUT argument list denotes: * 1-field 2-correction-eq. monitor 3-selective dumping * 4-whole-field residual 5-spot-value table 6-residual table OUTPUT(P1,Y,N,Y,Y,Y,Y) OUTPUT(AU1,Y,N,Y,Y,Y,Y) OUTPUT(BU2,Y,N,Y,Y,Y,Y) OUTPUT(CV1,Y,N,Y,Y,Y,Y) OUTPUT(DV2,Y,N,Y,Y,Y,Y) OUTPUT(GAS,N,N,N,N,N,N) OUTPUT(LIQ,Y,N,Y,Y,Y,Y) OUTPUT(SHAD,Y,N,Y,Y,Y,Y) OUTPUT(CFIP,Y,N,Y,N,N,N) OUTPUT(MDOT,Y,Y,Y,Y,Y,Y) ************************************************************ Group 22. Monitor Print-Out IXMON = 5 ;IYMON = 1 ;IZMON = 1 NPRMON = 100000 ;NPRMNT = 1 ;TSTSWP = -1 UWATCH = T ;USTEER = T HIGHLO = F ************************************************************ Group 23.Field Print-Out & Plot Control NPRINT = 100000 ;NUMCLS = 5 NXPRIN = 0 ;IXPRF = 1 ;IXPRL = 10000 NYPRIN = -1 ;IYPRF = 1 ;IYPRL = 10000 IPLTF = 1 ;IPLTL = -1 ;NPLT = 1 ISWPRF = 1 ;ISWPRL = 100000 ITABL = 1 ;IPROF = 1 ABSIZ =0.5 ;ORSIZ =0.4 NTZPRF = 1 ;NCOLPF = 50 ICHR = 2 ;NCOLCO = 45 ;NROWCO = 20 PATCH(XPROFILE,PROFIL, 1, 10, 1, 1, 1, 1, 1, 1) PLOT(XPROFILE,AU1 ,-1. ,-1. ) PLOT(XPROFILE,BU2 ,-1. ,-1. ) PLOT(XPROFILE,LIQ ,0. ,0. ) PLOT(XPROFILE,SHAD,0. ,0. ) PATCH(XPROFIL2,PROFIL, 1, 10, 1, 1, 1, 1, 1, 1) PLOT(XPROFIL2,CFIP,0. ,0. ) PLOT(XPROFIL2,MDOT,0. ,0. ) ************************************************************ Group 24. Dumps For Restarts SAVE = T ;NOWIPE = F NSAVE =CHAM STOP