AUTOPLOT USE file phi 5 da 1 p1 screen msg pressure pl 1 msg pressto continue pause cl da 1 u1 x 1 79 screen msg gas velocity pl 1 msg press to continue pause cl da 1 vliq x 1 79 screen msg liquid velocity pl 1 msg press to continue pause cl da 1 liq screen msg liquid volume fraction pl 1 msg press to continue pause cl da 1 iliq screen msg liquid enthalpy pl 1 msg press e to END enduse GROUP 1. Run title TEXT(BOILING , NO GRAVITY : W887 TITLE NUMERICAL BENCHMARK PROBLEM 1.3 STEADY BOILING IN A PIPE DISPLAY Description of flow. Saturated water enters a pipe of 1 m length, the first 0.25 m of which are unheated. Heat is supplied to the remainder of the pipe at a fixed rate (see group 13 below). The processes considered are:- * heat transfer from the wall to the liquid; * heat transfer from the liquid to the steam-water interface; * mass transfer across the interface, at a rate determined by the heat balance; * heat transfer between the interface and the bulk of the steam; * momentum transfer (friction) between the water and the steam; * pressure-gradient and inertia effects on the water and the steam. The task is to calculate the steady-state distributions along the pipe of pressure, volume fractions, enthalpies, and velocities. ENDDIS REAL(CHATIM,REFMAS,VELCTY,HEAT,XLEN,SIDE,AREA) VELCTY=0.01;HEAT=1.E5;XLEN=1.0;SIDE=0.01;AREA=SIDE*SIDE GROUP 2. Transience; time-step specification GROUP 3. X-direction grid specification GRDPWR(X,80,XLEN,1.0);YVLAST=SIDE;ZWLAST=SIDE GROUP 4. Y-direction grid specification GROUP 5. Z-direction grid specification GROUP 6. Body-fitted coordinates or grid distortion GROUP 7. Variables stored, solved & named ONEPHS=F;SOLVE(P1,U1,U2,H1,H2,R1,R2) NAME(R1)=GAS;NAME(R2)=LIQ;NAME(U2)=VLIQ;NAME(H2)=ILIQ ** Provide storage for inter-phase mass transfer STORE(MDOT) GROUP 8. Terms (in differential equations) & devices ** Cut off built-in sources and diffusion terms TERMS(H1,N,Y,N,Y,Y,Y);TERMS(ILIQ,N,Y,N,Y,N,Y) TERMS(GAS,Y,Y,N,Y,Y,Y);TERMS(LIQ,Y,Y,N,Y,N,Y) TERMS(U1,Y,Y,N,Y,Y,Y);TERMS(VLIQ,Y,Y,N,Y,N,Y) GROUP 9. Properties of the medium (or media) RHO2=1.E3;ENUL=0.0 GROUP 10. Inter-phase-transfer processes and properties ** Set constant inter-phase friction factor and activate the calculation of the inter-phase mass transfer by means of a heat balance between the two phases. Note that the minus sign is merely a signal to use the second-phase density. CFIPS=-50.0;CMDOT=HEATBL ** Set the inter-phase heat transfer coefficients CINT(H1)=1.E-2;CINT(ILIQ)=1.E0 MESG(Cut out inter-phase friction? (y/n) READVDU(ANS,CHAR,N) IF(:ANS:.EQ.Y) THEN CFIPS=CFIPS*1.E-5 CINT(H1)=CINT(H1)*1.E5 CINT(ILIQ)=CINT(ILIQ)*1.E5 ENDIF ** Set the values of the enthalpies at the interface PHINT(H1)=2.5E6;PHINT(ILIQ)=4.0E5 GROUP 11. Initialization of variable or porosity fields FIINIT(GAS)=1.E-2;FIINIT(LIQ)=0.99 FIINIT(H1)=2.5E6;FIINIT(ILIQ)=4.0E5 FIINIT(U1)=VELCTY;FIINIT(VLIQ)=VELCTY;FIINIT(MDOT)=0.0 GROUP 13. Boundary conditions and special sources ** Inlet at low-x (west) end INLET(INLET,WEST,1,1,1,1,1,1,1,1) VALUE(INLET,P2,VELCTY*RHO2) VALUE(INLET,VLIQ,VELCTY) VALUE(INLET,ILIQ,4.0E5) ** Outlet at high-x (east) PATCH(OUTLET,CELL,NX,NX,1,1,1,1,1,1) COVAL(OUTLET,P1,1.0,0.0);COVAL(OUTLET,P2,1.0*RHO2,0.0) COVAL(OUTLET,U1,ONLYMS,0.0);COVAL(OUTLET,VLIQ,ONLYMS,0.0) COVAL(OUTLET,H1,ONLYMS,SAME);COVAL(OUTLET,ILIQ,ONLYMS,SAME) ** Heated region PATCH(HOTWALL,PHASEM,NX/4+1,NX,1,1,1,1,1,1) COVAL(HOTWALL,ILIQ,FIXFLU,HEAT) GROUP 15. Termination of sweeps LSWEEP=500;SELREF=T;RESFAC=0.01 GROUP 16. Termination of iterations GROUP 17. Under-relaxation devices CHATIM=0.01*XLEN/VELCTY RELAX(P1,LINRLX,0.8) RELAX(U1,FALSDT,CHATIM);RELAX(VLIQ,FALSDT,CHATIM) RELAX(H1,FALSDT,0.1);RELAX(ILIQ,FALSDT,0.1) RELAX(GAS,LINRLX,0.3);RELAX(LIQ,LINRLX,0.3) GROUP 22. Spot-value print-out TSTSWP=-1;IXMON=NX/2 GROUP 23. Field print-out and plot control IPLTF=3;IPLTL=LSWEEP;NPLT=LSWEEP/20;ORSIZ=0.4;ITABL=1 PATCH(LONGPLOT,PROFIL,1,NX,1,1,1,1,1,1);PLOT(LONGPLOT,P1,0.0,0.0) PLOT(LONGPLOT,LIQ,0.0,0.0);PLOT(LONGPLOT,U1,-1.0,-1.0) PLOT(LONGPLOT,VLIQ,-1.0,-1.0);PLOT(LONGPLOT,MDOT,0.0,0.0) GROUP 24. Dumps for restarts