GROUP 1. Run title and other preliminaries TEXT(Laminar Natural Convec In A Cavity TITLE DISPLAY This case is the three-dimensional counterpart of case 251, but with a somewhat coarser grid in the y-z plane. The cavity is now a cubical box, with adiabatic end walls. Only one half of the domain is included, by reason of symmetry. ENDDIS The locally-defined variables are as follows: DVO1DT The coefficient of thermal expansion 1/K AGRAV Gravity m/s^2 TREF Reference temperature C deg. BOXL The length of the box m REAL(TREF,AGRAV,BOXL) DVO1DT=2.874E-1*CP1; AGRAV=9.81; TREF=0.0; BOXL=3.626E-02 GROUP 3. X-direction grid specification IREGX=1; GRDPWR(X,5,0.5*BOXL,1.0) GROUP 4. Y-direction grid specification *** The value YVLAST = ZWLAST = BOXL , determines the Rayleigh number This run set for Ra=1.E5 (a laminar value) NREGY=3 IREGY=1; GRDPWR(Y, 5,5.439e-3,1.0) IREGY=2; GRDPWR(Y,10,0.02538 ,1.0) IREGY=3; GRDPWR(Y, 5,5.439e-3,1.0) GROUP 5. Z-direction grid specification IREGZ=1; GRDPWR(Z,30,BOXL,1.0) GROUP 7. Variables stored, solved & named *** Whole-field solver for P1 is activated. SOLVE(P1,U1,V1,W1,H1); SOLUTN(P1,Y,Y,Y,N,N,N); NAME(H1)=TEMP GROUP 8. Terms (in differential equations) & devices *** Deactivate the built-in source in TEMP equation. TERMS(TEMP,N,Y,Y,Y,Y,Y) csg3=cngr GROUP 9. Properties of the medium (or media) RHO1=1.207; ENUL=1.5E-04; PRNDTL(TEMP)=0.71 GROUP 11. Initialization of variable or porosity fields FIINIT(P1)=1.0E-06; FIINIT(V1)=0.05; FIINIT(W1)=0.05 GROUP 13. Boundary conditions and special sources 1. Hot wall boundary: constant temperature of 10 deg. WALL (HOT,SOUTH,#1,#NREGX,#1,#1,#1,#NREGZ,1,1) COVAL(HOT,W1,1.0,0.0);COVAL(HOT,U1,1.0,0.0) COVAL(HOT,TEMP,1.0,10.0) 2. Cold wall boundary: constant temperature of -10 deg. WALL (COLD,NORTH,#1,#NREGX,#NREGY,#NREGY,#1,#NREGZ,1,1) COVAL(COLD,W1,1.0,0.0);COVAL(COLD,U1,1.0,0.0) COVAL(COLD,TEMP,1.0,-10.) 3. Low wall boundary: Adiabatic but with friction WALL (LOWAL,LOW,#1,#NREGX,#1,#NREGY,#1,#1,1,1) COVAL(LOWAL,V1,1.0,0.0);COVAL(LOWAL,U1,1.0,0.0) 4. High wall boundary: Adiabatic but with friction WALL (HIWAL,HIGH,#1,#NREGX,#1,#NREGY,#NREGZ,#NREGZ,1,1) COVAL(HIWAL,V1,1.0,0.0);COVAL(HIWAL,U1,1.0,0.0) 5. West wall boundary: Adiabatic but with friction WALL (WESTWAL,WEST,#1,#1,#1,#NREGY,#1,#NREGZ,1,1) COVAL(WESTWAL,W1,1.0,0.0);COVAL(WESTWAL,V1,1.0,0.0) 6. Buoyancy force *** Buoyancy source for the z-direction momentum equation is set in GREX3, Group 13, Sec.15, and GXBUOY; VAL=GENLAW activates the Boussinesq approximation as follows: RHO*Volume*grav.*DVO1DT*(Tref-T). The following data need to be set for this purpose: BUOYE=TREF; BUOYC=grav. BUOYE=0.0; BUOYC=-AGRAV PATCH(BUOY,PHASEM,1,NX,1,NY,1,NZ,1,1); COVAL(BUOY,W1,FIXFLU,BOUSS) 7. Reference pressure at centre of cavity PATCH(FIXPRESS,CELL,NX,NX,NY/2,NY/2,NZ/2,NZ/2,1,1) COVAL(FIXPRESS,P1,FIXP,0.0);COVAL(FIXPRESS,U1,ONLYMS,0.0) COVAL(FIXPRESS,V1,ONLYMS,0.0);COVAL(FIXPRESS,W1,ONLYMS,0.0) GROUP 15. Termination of sweeps LSWEEP=200 GROUP 16. Termination of iterations LITER(P1)=-30; LITER(U1)=20; LITER(V1)=20; liter(w1)=20 GROUP 17. Under-relaxation devices RELAX(U1,FALSDT,1.E-2); RELAX(V1,FALSDT,1.E-2) RELAX(W1,FALSDT,1.E-02) GROUP 22. Spot-value print-out IYMON=3; IZMON=20 ; tstswp=-5 GROUP 23. Field print-out and plot control NYPRIN=NY/5; NZPRIN=NZ/5; NPLT=1 *** Temperature and velocity profiles PATCH(PROF,PROFIL,1,1,1,NY,NZ/2,NZ/2,1,1) PLOT (PROF,W1,0.0,0.0); PLOT (PROF,TEMP,-10.0,10.0) *** Temperature contours PATCH(CONT,CONTUR,1,1,1,NY,1,NZ,1,1) PLOT (CONT,TEMP,0.0,10.0)