PHOTON USE p;;;;; up z msg grid gr x 1 msg Pressto continue pause; cl msg 1st-phase (liquid) velocity vectors set vec ref;0.5;vec x 1 sh; gr ou x 1 msg Press to continue pause; cl msg 2nd-phase (solid) velocity vectors set vec comp; - v2 e2; vec x 1 sh; gr ou x 1 msg Press to continue pause ; cl msg contour of pressure con p1 x 1 fi;0.002; gr ou x 1 msg Press to continue pause; cl msg contour of 1st-phase (liquid) volume fraction con r1 x 1 fi;0.002; gr ou x 1 msg Press to continue pause; cl msg contour of soluble material concentration con c1 x 1 fi;0.002; gr ou x 1 msg Press to continue pause; cl msg contour of 1st-phase (liquid) enthalpy con liqt x 1 fi;0.002; gr ou x 1 msg Press to continue pause; cl msg contour of 2nd-phase (solid) enthalpy con solt x 1 fi;0.002; gr ou x 1 msg Press e to END enduse GROUP 1. Run title TEXT(STIRRED TANK; RUN1 STRONG STIRRING: W918 TITLE DISPLAY * A finely-divided solid is supposed to be uniformly distributed within a liquid, which is at rest in a cylindrical container, of diameter 1 meter and height 1 meter. The particles and liquid are at different temperatures; and the particles are soluble in the liquid. * A paddle wheel, situated on the axis near the floor of the tank, is suddenly set in motion. * The subsequent motions of the liquid and of the particles are computed, together with their changes in temperature, and the increase in concentration of the soluble material in the liquid. * Three runs are set up, with varying paddle speed. It is suggested that a series of runs should be performed, showing the influences on the rate of dissolution of, for example:- * the paddle speed; * the paddle size; * the density ratio between solid and liquid; * the various factors influencing the transfer rates of heat, mass and momentum between the particles and their surroundings;etc. Note that 100 sweeps per time step are needed for convergence. ENDDIS Special variables introduced for this problem are:- UDRPAD= circumferential velocity u divided by radius imposed by paddle HEIGHT & DIAM have obvious meanings CHATIM= characteristic time of the process REAL(UDRPAD,HEIGHT,DIAM,CHATIM) UDRPAD=20.0;HEIGHT=1.0;DIAM=1.0 CHATIM=0.1*HEIGHT/UDRPAD GROUP 2. Transience; time-step specification The process is simulated for a 10-second period, divided into 10 equal intervals STEADY=F;GRDPWR(T,10,10.0,1.0) GROUP 3. X-direction grid specification CARTES=F;xulast=0.1 GROUP 4. Y-direction grid specification GRDPWR(Y,10,DIAM/2.0,1.0) GROUP 5. Z-direction grid specification GRDPWR(Z,10,HEIGHT,1.0) GROUP 7. Variables stored, solved & named ONEPHS=F;SOLVE(P1,U1,U2,V1,V2,W1,W2,R1,R2,H1,H2,C1,C2) STORE(INTMDT) NAME(H1)=LIQT;NAME(H2)=SOLT;NAME(INTMDT)=MDOT;NAME(C2)=D2 NAME(W2)=E2 GROUP 9. Properties of the medium (or media) ENUL=1.E-2;ENUT=0.01*DIAM**2*UDRPAD PRNDTL(LIQT)=5.0;RHO1=1.E3;RHO2=2.0*RHO1 GROUP 10. Inter-phase-transfer processes and properties CFIPS=GRND2;CFIPA=0.01;CFIPC=1.E4 CINT(LIQT)=0.01;CINT(SOLT)=0.001 CINT(C1)=0.0;CINT(D2)=0.0;PHINT(C1)=1.0;PHINT(D2)=1.0;CMDOT=1.E-4 GROUP 11. Initialization of variable or porosity fields FIINIT(R1)=0.99;FIINIT(R2)=0.01;FIINIT(LIQT)=0.0;FIINIT(SOLT)=1.0 FIINIT(C1)=0.0;FIINIT(D2)=1.0;FIINIT(MDOT)=0.0 GROUP 13. Boundary conditions and special sources Cylindrical-wall friction WALL (CYLWALL,NORTH,1,1,NY,NY,1,NZ,1,LSTEP) COVAL(CYLWALL,W1,1.0,0.0);COVAL(CYLWALL,E2,1.0,0.0) COVAL(CYLWALL,U1,1.0,0.0);COVAL(CYLWALL,U2,1.0,0.0) Top-wall friction WALL (TOP,HIGH,1,1,1,NY,NZ,NZ,1,LSTEP) COVAL(TOP,U1,1.0,0.0);COVAL(TOP,U2,1.0,0.0) COVAL(TOP,V1,1.0,0.0);COVAL(TOP,V2,1.0,0.0) Bottom-wall friction WALL (BOTTOM,LOW,1,1,1,NY,1,1,1,LSTEP) COVAL(BOTTOM,U1,1.0,0.0);COVAL(BOTTOM,U2,1.0,0.0) COVAL(BOTTOM,V1,1.0,0.0);COVAL(BOTTOM,V2,1.0,0.0) Pressure-relief condition to ensure that problem is well-posed PATCH(PRELIEF,HIGH,1,1,NY,NY,NZ,NZ,1,100) COVAL(PRELIEF,P1,FIXP,0.0) COVAL(PRELIEF,LIQT,ONLYMS,0.0);COVAL(PRELIEF,C1,ONLYMS,0.0) Paddle condition, a fixed value for the liquid u/r PATCH(PADDLE,CELL,1,1,NY/2,NY/2,1,NZ/5,1,LSTEP) IURVAL=-1;COVAL(PADDLE,U1,FIXVAL,UDRPAD) Gravity exerts a downward force on both phases PATCH(GRAVITY,PHASEM,1,1,1,NY,1,NZ,1,LSTEP) COVAL(GRAVITY,W1,FIXFLU,-9.81);COVAL(GRAVITY,E2,FIXFLU,-9.81) GROUP 15. Termination of sweeps The following conditions are not necessarily optimal LSWEEP=20;SELREF=T;RESFAC=0.1 GROUP 17. Under-relaxation devices RELAX(W1,FALSDT,CHATIM);RELAX(V1,FALSDT,CHATIM) RELAX(E2,FALSDT,CHATIM);RELAX(V2,FALSDT,CHATIM) RELAX(U1,FALSDT,CHATIM);RELAX(U2,FALSDT,CHATIM) RELAX(R1,LINRLX,0.75);RELAX(R2,LINRLX,0.75) SPEDAT(SET,GXMONI,TRANSIENT,L,F) GROUP 22. Spot-value print-out TSTSWP=-1;NPRMON=20;IYMON=NY-1;IZMON=NZ-1 GROUP 23. Field print-out and plot control IURPRN=-1;NYPRIN=NY/5;NXPRIN=NZ/5 Field print-out for liquid volume fraction is suppressed OUTPUT(R1,N,Y,Y,Y,Y,Y) Line-printer contour plots for various quantities are called for PATCH(MAP,CONTUR,1,1,1,NY,1,NZ,1,LSTEP) PLOT(MAP,W1,0.0,10);PLOT(MAP,E2,0.0,10) PLOT(MAP,U1,0.0,10);PLOT(MAP,V1,0.0,10) PLOT(MAP,LIQT,0.0,10);PLOT(MAP,R2,0.0,10) PLOT(MAP,SOLT,0.0,10);PLOT(MAP,C1,0.0,10.0) PLOT(MAP,MDOT,0.0,10.0) A line-printer profile plot for the topmost-but-one slab is called for PATCH(IZEQNZM1,PROFIL,1,1,1,NY,NZ-1,NZ-1,1,LSTEP) PLOT(IZEQNZM1,W1,0.0,0.0);PLOT(IZEQNZM1,E2,0.0,0.0) PATCH(IZEQNZD2,PROFIL,1,1,1,NY,1,NZ/2,1,LSTEP) PLOT(IZEQNZD2,W1,-1.0,-1.0);PLOT(IZEQNZD2,E2,-1.0,-1.0) PLOT(IZEQNZD2,R2,0.0,0.0) PATCH(TIMEPLOT,PROFIL,1,1,NY/2,NY/2,NZ/2,NZ/2,1,LSTEP) PLOT(TIMEPLOT,LIQT,-2.0,-2.0);PLOT(TIMEPLOT,SOLT,-2.0,-2.0) PLOT(TIMEPLOT,U1,0.0,0.0);PLOT(TIMEPLOT,V1,0.0,0.0) PLOT(TIMEPLOT,W1,0.0,0.0) PLOT(TIMEPLOT,R2,0.0,0.0);PLOT(TIMEPLOT,C1,0.0,0.0)