PHOTON USE p gr ou y 1 MSG Velocity vectors vec y 1 sh msg msg Press return to plot pressure contours pause cont p1 y 1 fil;.01 msg msg Type e to End ENDUSE GROUP 1. Run title TEXT(SUPERSONIC FLOW THRU WEDGE CASCADE: B523 TITLE DISPLAY The flow considered is supersonic flow through a cascade of wedges with inlet Mach number 3.0 and completely supersonic flow. A leading-edge shock reflects off the pressure surface and should be exactly cancelled at the upstream corner giving a uniform parallel flow through the two surfaces. The flow then expands off the downstream corner and exits through the blade row where two compression waves are formed at the trailing edge. Cyclic boundary conditions are applied upstream and downstream of the cascade. The geometry is as follows: wall ////////////////////////////////////////////////////// ------------------------------------------------------ ---------> zero ---> ---------> ---> pressure ____________________ .'////////////////////`. ---> .'| wall -`. ---> .'| wall wall -`. ___________.'| -`._______ /////////// /////// ^ wall wall x| |---> z CHAR(ANSW) mesg(Press return to continue readvdu(answ,char,y) For simplicity, the flow is treated as isentropic. However, shock theory indicates that there is a significant entropy change across the shocks for the given approach Mach number and wedge angle. Therefore, in future work the isentropic treatment will be replaced with one which allows for entropy changes across shock fronts. The exit boundary condition is one of fixed pressure according to the post-expansion pressure calculated from gas-dynamic theory; this neglects the presence of trailing-edge shocks. Strictly, the flow is hyperbolic and so the exit boundary condition should be modified accordingly. The system of units used are the same as those used in case 522. ENDDIS REAL(GASCON,GAMMA,PTOTAL,TTOTAL,RHOTOT,MACHI,PEXRAT,AGAM1,RGAM) REAL(PIN,TIN,POWER,WIN,RHOIN,PEXIT,CHORD) REAL(ANGLE1,GZLE,GZBACK,GZFCOR,GZSCOR,GZTE) INTEGER(IZLE,IZTE,KASE) GASCON=1.0;GAMMA=1.4;PTOTAL=1.0;TTOTAL=1.0;RHOTOT=1.0;MACHI=3.0 CHORD=4.0;PEXRAT=0.0377 IZLE=4;IZTE=24;ANGLE1=18.5;GZLE=0.8;GZTE=GZLE+CHORD;GZBACK=0.8 GZFCOR=GZLE+2.0;GZSCOR=GZLE+3.0 KASE=2 ** Calculation of inlet velocity AGAM1=GAMMA-1.; RGAM=1./GAMMA;POWER=GAMMA/AGAM1 PIN=PTOTAL/(1.+AGAM1*MACHI*MACHI/2.)**POWER RHOIN=RHOTOT/(PTOTAL/PIN)**RGAM WIN=MACHI*(GAMMA*PIN/RHOIN)**0.5 ** Calculation of Inlet Temperature TIN=PIN/(GASCON*RHOIN) ** Calculation of exit pressure PEXIT=PEXRAT*PTOTAL GROUP 6. Body-fitted coordinates or grid distortion BFC=T;NONORT=T GSET(D,10,1,28,1.0,1.0,5.6) INTEGER(K1,K2,K3,K4);K1=5;K2=15;K3=20;K4=25 ** Centre portion GSET(C,I1,F,I:NX+1:,1,NY,K2,K3-1,+,-0.3308,0.0,0.0,INC,1.0) ** Front Ramp GSET(T,K:K2:,F,K:K1:,1.0) ** Rear Ramp GSET(T,K:K4:,F,K:K3:,1.0) GROUP 7. Variables stored, solved & named SOLVE(P1,U1,W1);STORE(RHO1) SOLUTN(P1,Y,Y,Y,N,N,N) GROUP 9. Properties of the medium (or media) ENUL=0.0;ENUT=0.0 ** Use Isentropic Density Law RHO1=COMPRESS; RHO1A=RHOTOT/PTOTAL**RGAM; RHO1B=RGAM RHO1C=0.;PRESS0=0.;DRH1DP=COMPRESS GROUP 11. Initialization of variable or porosity fields FIINIT(P1)=PIN;FIINIT(W1)=WIN;FIINIT(RHO1)=RHOIN GROUP 13. Boundary conditions and special sources INLET(INLET,LOW,1,NX,1,1,1,1,1,1) VALUE(INLET,P1,RHOIN*WIN) VALUE(INLET,W1,WIN) PATCH(OUTLET,HIGH,1,NX,1,1,NZ,NZ,1,1) COVAL(OUTLET,P1,5.E4,PEXIT) COVAL(OUTLET,U1,ONLYMS,0.0);COVAL(OUTLET,W1,ONLYMS,0.0) ** Cyclic boundary upstream and downstream of cascade. XCYIZ(1,K1-1,T);XCYIZ(K4,NZ,T) GROUP 15. Termination of sweeps LSWEEP=100 GROUP 16. Termination of iterations LITER(P1)=15 GROUP 17. Under-relaxation devices RELAX(P1,LINRLX,0.8); RELAX(RHO1,LINRLX,1.0) RELAX(U1,FALSDT,0.5); RELAX(W1,FALSDT,0.5) GROUP 18. Limits on variables or increments to them VARMIN(U1)=-50.;VARMIN(W1)=-50.;VARMAX(U1)=50.;VARMAX(W1)=50. VARMIN(RHO1)=0.1*RHOIN;VARMAX(RHO1)=RHOTOT VARMIN(P1)=0.01*PIN;VARMAX(P1)=PTOTAL GROUP 22. Spot-value print-out IXMON=2;IZMON=9;NPRMON=LSWEEP SELREF=T; RESFAC=0.01 GROUP 23. Field print-out and plot control NPRINT=LSWEEP;TSTSWP=-1 PATCH(PLOT1,PROFIL,NX/2,NX/2,1,1,1,NZ,1,1) PLOT(PLOT1,P1,0.0,0.0) PATCH(CASCADE,CONTUR,1,NX,1,1,1,NZ,1,1) PLOT(CASCADE,P1,0.0,20.0);PLOT(CASCADE,W1,0.0,20.0)