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)