PHOTON USE p gr ou x 1 MSG Velocity vectors vec x 1 sh msg msg Press return to plot pressure contours pause cont p1 x 1 fil;.01 msg msg Type e to End ENDUSE GROUP 1. Run title TEXT(POTENTIAL FLOW AROUND 1/2 CYLINDER: B514 #cls TITLE DISPLAY This case defines a calculation of the potential flow about a half cylinder in a duct in the y-z plane. The grid is generated by PIL commands giving a 'shear transformation' and is non-orthogonal; so NONORT is set T. The potential calculation is contrived by introducing a uniform high resistance throughout the flow field. This 'Darcy' flow is mathematically equivalent to potential flow. This is done in Group 13 by setting DARCY=T, which creates the appropriate PATCH and COVAL settings. An analytical solution exists for this case to which the results may be compared (see Milne-Thompson, 1962, 'Theoretical Hydrodynamics') ENDDIS #pause GROUP 6. Body-fitted coordinates or grid distortion BFC=T;NONORT=T ** Set grid dimension. GSET(D,1,10,20,1.0,1.0,2.0) INTEGER(IZ1,IZ2,DNZ);IZ1=6;IZ2=16;DNZ=NZ/4 REAL(AA,ZS1,ZM);AA=ZWLAST/3;ZM=ZWLAST*0.5 ** Set corner points for whole frame. GSET(P,A,0.0,0.0,0.0) GSET(P,B,0.0,YVLAST,0.0) GSET(P,E,0.0,YVLAST,ZWLAST) GSET(P,F,0.0,0.0,ZWLAST) ** Set corner points for cylinder. GSET(P,G,0.0,0.0,AA*2.0) GSET(P,H,0.0,0.0,AA) GSET(P,C,0.0,YVLAST,AA) GSET(P,D,0.0,YVLAST,AA*2.0) -- North boundary of cylinder GSET(L,L3,C,D,DNZ*2,1.0) -- South boundary of cylinder .. The S0.62 term only approximates even division in Z-direction GSET(L,L7,G,H,DNZ*2,S0.57,ARC,0.0,AA/2.0,ZWLAST/2.0) -- Rest of the frame GSET(L,L2,B,C,DNZ,1.0) GSET(L,L4,D,E,DNZ,1.0) GSET(L,L6,F,G,DNZ,1.0) GSET(L,L8,H,A,DNZ,1.0) GSET(L,L1,A,B,NY,1.0) GSET(L,L5,E,F,NY,1.0) ** Define frame. GSET(F,F1,A,-,B,C.D,E,-,F,G.H) ** Match defined frame onto I1. GSET(M,F1,+J+K,1,1,1,TRANS) ** Copy I1 to I2 GSET(C,I2,F,I1,+,1,0,0) GROUP 7. Variables stored, solved & named ** Solve for pressure (whole-field) and velocity. SOLUTN(P1,Y,Y,Y,N,N,N) ISOLZ=1 GROUP 9. Properties of the medium (or media) RHO1=1.0;ENUL=1.0E-10 GROUP 11. Initialization of variable or porosity fields FIINIT(W1)=1.0 GROUP 13. Boundary conditions and special sources ** Inlet INLET(INLET,LOW,1,NX,1,NY,1,1,1,1) VALUE(INLET,P1,1.0);VALUE(INLET,W1,1.0) ** Outlet PATCH(OUTLET,HIGH,1,NX,1,NY,NZ,NZ,1,1);COVAL(OUTLET,P1,FIXP,0.0) COVAL(OUTLET,V1,ONLYMS,0.0);COVAL(OUTLET,W1,ONLYMS,0.0) ** Whole field flow-resistance DARCY=T GROUP 15. Termination of sweeps LSWEEP=20 GROUP 22. Spot-value print-out NPLT=1;IYMON=3;IZMON=10 GROUP 23. Field print-out and plot control IZPRF=5;IZPRL=15 PATCH(YZ,CONTUR,1,1,1,NY,1,NZ,1,1);PLOT(YZ,P1,0.0,20.0) PLOT(YZ,W1,0.0,20.0) PATCH(INNER,PROFIL,1,1,1,1,1,NZ,1,1) PLOT(INNER,P1,0.0,0.0);PLOT(INNER,W1,0.0,0.0) **The following 4 cases deal with the flow over an ellipse, but since the flow layout is identical to this case (i.e. in the Y-Z plane with the same inflow and outflow boundaries).