PHOTON USE p phi msg Irrotational flow past an inclined plate msg set ref vec 5 msg Velocity vectors: gr ou z 1;gr ou z 1 x 2 m y 2 m;vec z 1 sh msg msg Pressto continue pause vec off;red msg west to east velocity contours: con u1 z 1 x 2 m y 2 m fi;.01 msg msg Press to continue pause msg south to north velocity contours: con v1 z 1 x 2 m y 2 m fi;.01 msg msg Press to continue pause con off;red msg Contours of stream function at cell centres: con PSID z 1 x 2 m y 2 m sh; int 20 pause msg Streamlines deduced from velocities by PHOTON stre 2d z 1 x 2 m y 2 m sh; int 20 msg Press e to END enduse GROUP 1. Run title and other preliminaries TEXT(Irrotational Flow; Inclined Plate #cls TITLE DISPLAY A plate is held centrally in a square box through the walls of which flows an inviscid fluid. The stream function is fixed to fit the formula: PSIV = a * x - b * y where a = - 1 and b = 1 (which can of course be changed by editing the Q1 file) The task is to compute the flow field within the box. In-Form is used in order to specify the boundary conditions. The plate is represented by setting the stream function to zero. ENDDIS #pause GROUPs 3, 4 and 5: grid specification nx=40; ny=40; nz=1 xulast=1.0; yvlast=1.0; zwlast=1.0 #unigrid GROUP 7. Variables stored, solved & named STORE(PSIV,PSID,U1,V1); SOLUTN(PSIV,Y,Y,Y,N,N,N) **Plate PATCH(PLATE,CELL,NX/2,NX/2,NY/4+1-1,3*NY/4,1,1,1,1) COVAL(PLATE,PSIV,FIXVAL,0.0) GROUP 13. Boundary conditions and special sources PATCH(NORTH,NORTH,2, NX-1,NY,NY,1,1,1,1) PATCH(SOUTH,SOUTH,2, NX-1,1 ,1 ,1,1,1,1) PATCH(EAST ,EAST ,NX,NX, 1 ,NY,1,1,1,1) PATCH(WEST ,WEST ,1 , 1, 1 ,NY,1,1,1,1) INFORM13BEGIN REAL(AA,BB) AA=-1; BB= 1 (source of PSIV at north is aa*xg + bb*yg with fixval) (source of PSIV at south is aa*xg + bb*yg with fixval) (source of PSIV at east is aa*xg + bb*yg with fixval) (source of PSIV at west is aa*xg + bb*yg with fixval) INFORM13END GROUP 15. Termination of sweeps LSWEEP = 1 GROUP 16. Termination of iterations LITER(PSIV)=-500;endit(psiv)=1.e-9;selref=f;resref(psiv)=1.e-20 GROUP 22. Spot-value print-out UWATCH=T GROUP 23. Field print-out and plot control PATCH(CONT,CONTUR,1,NX,1,NY,1,1,1,1);PLOT(CONT,PSIV,0.0,20.0) GROUP 24. Dumps for restart