PHOTON USE p phi 5 1 msg grid gr z 1 msg Pressto continue pause cl msg 1st-phase velocity vectors at t=5s set vec ref;1 set vec comp au1 cv1 - vec z 1 sh gr ou z 1 msg Press to continue pause cl msg 2nd-phase velocity vectors at t=5s set vec ref;1 set vec comp bu2 dv2 - vec z 1 sh gr ou z 1 msg Press to continue pause cl msg contour of pressure at t=5s con p1 z 1 fi;0.002 gr ou z 1 msg Press to continue pause cl msg contour of 1st-phase volume fraction at t=5s con r1 z 1 fi;0.002 gr ou z 1 msg Press to continue pause cl msg contour of 1st-phase volume fraction at t=5s con r2 z 1 fi;0.002 gr ou z 1 msg Press e to END enduse GROUP 1. Run title and other preliminaries TEXT(THE TILTING OF A BOX : W427 TITLE DISPLAY A light fluid lies above a heavy one in a box which is suddenly tilted, so that gravity acts along the diagonal. Friction at the walls is neglected. The donor-acceptor option is activated, in Group 8, so as to diminish the extent of the blurring of the interface, which it does not however eliminate entirely. That it does some good can be checked by re-running with DONACC=F. ENDDIS GROUP 2. Transience; time-step specification STEADY=F;GRDPWR(T,10,0.1,1.0) GROUP 3. X-direction grid specification GRDPWR(X,5,1.0,1.0) GROUP 4. Y-direction grid specification GRDPWR(Y,5,1.0,1.0) GROUP 7. Variables stored, solved & named ONEPHS=F;SOLVE(P1,U1,V1,U2,V2,R1,R2) NAME(U1)=AU1;NAME(U2)=BU2;NAME(V1)=CV1;NAME(V2)=DV2 GROUP 8. Terms (in differential equations) & devices RLOLIM=0.01;RUPLIM=1.0-RLOLIM;DONACC=T GROUP 9. Properties of the medium (or media) RHO2=1.E3;ENUL=1.E-3 GROUP 10. Inter-phase-transfer processes and properties CFIPS=1.E9 GROUP 11. Initialization of variable or porosity fields FIINIT(R1)=1.0;FIINIT(R2)=0.0;FIINIT(P1)=0.0 FIINIT(AU1)=0.;FIINIT(CV1)=0.;FIINIT(BU2)=0.;FIINIT(DV2)=0. INIADD=T PATCH(INIT,INIVAL,1,NX,1,2,1,1,1,1) INIT(INIT,R1,0.0,-1.0);INIT(INIT,R2,0.0,1.0) INIT(INIT,P1,0.0,1.0E3) GROUP 13. Boundary conditions and special sources ** Pressure relief PATCH(REFP,CELL,NX,NX,NY,NY,1,1,1,LSTEP);COVAL(REFP,P1,FIXVAL,0.0) ** Gravity PATCH(GRAVITY,PHASEM,1,NX,1,NY,1,1,1,LSTEP) COVAL(GRAVITY,AU1,FIXFLU,-10.0);COVAL(GRAVITY,BU2,FIXFLU,-10.0) COVAL(GRAVITY,CV1,FIXFLU,-10.0);COVAL(GRAVITY,DV2,FIXFLU,-10.0) GROUP 15. Termination of sweeps LSWEEP=20;RESREF(P1)=1.E-5;RESREF(R1)=1.E-5;RESREF(R2)=1.E-5 GROUP 17. Under-relaxation devices RELAX(R1,LINRLX,0.25);RELAX(R2,LINRLX,0.25) RELAX(AU1,FALSDT,0.01);RELAX(CV1,FALSDT,0.01) RELAX(BU2,FALSDT,0.01);RELAX(DV2,FALSDT,0.01) GROUP 19. Data communicated by satellite to GROUND USEGRX=F SPEDAT(SET,GXMONI,TRANSIENT,L,F) GROUP 21. Print-out of variables OUTPUT(R2,N,N,N,N,N,N) GROUP 22. Spot-value print-out IXMON=4;IYMON=4;TSTSWP=-1 GROUP 23. Field print-out and plot control NTPRIN=LSTEP/5;ITABL=1;IPLTL=LSWEEP PATCH(CONT,CONTUR,1,NX,1,NY,1,1,1,LSTEP);PLOT(CONT,R2,0.0,10)