NOTE Similar to 522 but added enthalpy and questions PHOTON USE p gr y 1 msg The body-fitted-coordinate grid msg - msg Pressto continue pause gr off;gr ou y 1; red msg Contours of pressure con p1 y 1 fi;0.001 msg - msg Press to continue pause con del;red *msg Contours of temperature *con temp y 1 fi;0.001 *msg - *msg Press to continue *pause msg velocity vectors vec y 1 sh msg - msg Press e to END enduse GROUP 1. Run title TEXT(TRANSONIC FLOW IN A CONV.DIV. NOZZLE:B422 TITLE mesg(PC486/50 time last reported as appx. 1.min DISPLAY The calculation is made using the BFC system, and the nozzle geometry corresponds to a linear Mach-number distribution, as predicted by one-dimensional gas-dynamic theory. The geometry is sketched out in the following diagram. /////// ////// *******/// ///// ** * // wall ////// * ---> zero ---> * //////// * pressure * * ---> ---------> ---> ************************************************ //////////////////////////////////////////////// The inlet conditions are prescribed total pressure and total temperature at a Mach Number of 0.5. The design outlet Mach number is 2.0 for which Pex/Po,in = .1278. The exit boundary condition corresponds to a fixed pressure at the expected nodal Mach number. A system of units is chosen whereby the flow variables can be interpreted as: P/Po,in ; RHO/RHOo,in ; T/To,in ; and U*SQRT(GAMMA)/Ao. Here, Ao is the acoustic velocity at the stagnation temperature. enddis GROUP 1. Run title TEXT(Plane transonic flow through a nozzle) REAL(GASCON,GAMMA,PTOTAL,TTOTAL,RHOTOT,MACHI,AGAM1,RGAM) REAL(MACHO,PIN,TIN,POWER,WIN,RHOIN,PEXIT,WEXIT,RHOOUT,GZLE) REAL(CHORD,THROAT,GRADP,GRADW,GRADR,CMASS,VMASS,cpin,HIN) GASCON=287;GAMMA=1.4;PTOTAL=3.0E5;TTOTAL=3.0E2;RHOTOT=3.5;MACHI=0.5 GZLE=0.4;CHORD=3.0;THROAT=0.5;MACHO=2.0 INTEGER(IZLE,IZTE);IZLE=2;IZTE=17 ** 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 TIN=PIN/(GASCON*RHOIN) cpin=gamma*gascon/agam1;hin=cpin*tin PEXIT=PTOTAL/(1.+AGAM1*MACHO*MACHO/2.)**POWER mesg(Inlet total pressure is :ptotal: mesg(outlet pressure is :pexit:. OK? If not, insert new value. readvdu(pexit,real,:pexit:) mesg(outlet pressure = :pexit: RHOOUT=RHOTOT/(PTOTAL/PEXIT)**RGAM WEXIT=MACHO*(GAMMA*PEXIT/RHOOUT)**0.5 GROUP 6. Body-fitted coordinates or grid distortion mesg(The body-fitted-coordinate option is used for mesg(representing the shape of the nozzle BFC=T;NONORT=T GSET(D,5,1,17,0.3350,1.0,CHORD+GZLE) IZTE=NZ ** Obtain constants for A/A* expression REAL(G5,G6,AAA,BBB,AAT,AT,MMO) G5=GAMMA+1.0;G6=G5/(2.0*AGAM1) AAA=2.0/G5;BBB=AGAM1/G5 AAT=((AAA+BBB*MACHI*MACHI)**G6)/MACHI AT=XULAST/AAT MMO=MACHO-MACHI REAL(XX,XNK) DO II=NZ,IZLE,-1 XNK=(II-IZLE)/(NZ-IZLE) XX=AT/(MACHI+MMO*XNK)*(AAA+BBB*(MACHI+MMO*XNK)**2)**G6 GSET(C,I:NX+1:,F,I1,1,NY,:II:,:II:,+,XX,0.0,0.0,INC,1.0) ENDDO GROUP 7. Variables stored, solved & named SOLVE(P1,U1,W1,H1);STORE(RHO1,TMP1);SOLUTN(P1,Y,Y,Y,N,N,N) ASSUME SOLVING STATIC ENTHALPY TMP1=LINH CP1=CPIN GROUP 8. Terms (in differential equations) & devices GROUP 9. Properties of the medium (or media) TERMS(U1,Y,Y,N,N,Y,N);TERMS(W1,Y,Y,N,N,Y,N) PRESS0=PEXIT USE IDEAL GAS EQUATION FOR DENSITY mesg(The flow is isentropic; and the density is calculated mesg(from the Ideal Gas Law RHO1=IDEALGAS;drh1dp=IDEALGAS RHO1B=1./287 CP1=CPIN GROUP 11. Initialization of variable or porosity fields FIINIT(W1)=0.5*(WIN+WEXIT) FIINIT(H1)=HIN FIINIT(RHO1)=RHOIN GROUP 13. Boundary conditions and special sources PATCH(INLET,LOW,1,NX,1,1,1,1,1,1) VMASS=RHOIN*PTOTAL/RHOTOT;CMASS=2.*POWER/WIN COVAL(INLET,P1,FIXFLU,RHOIN*WIN);COVAL(INLET,W1,ONLYMS,WIN) COVAL(INLET,H1,ONLYMS,hin) PATCH(OUTLET,HIGH,1,NX,1,1,NZ,NZ,1,1) COVAL(OUTLET,P1,1.0E5,0.0) COVAL(OUTLET,U1,ONLYMS,0.0);COVAL(OUTLET,W1,ONLYMS,0.0) COVAL(OUTLET,H1,ONLYMS,3.E5) GROUP 15. Termination of sweeps LSWEEP=300 GROUP 17. Under-relaxation devices RELAX(P1,LINRLX,0.3) RELAX(W1,FALSDT,5.E-3) RELAX(U1,FALSDT,5.E-3) GROUP 21. Print-out of variables OUTPUT(RHO1,Y,N,N,N,Y,Y) GROUP 22. Spot-value print-out IXMON=2;IZMON=12 GROUP 23. Field print-out and plot control NPRINT=LSWEEP GROUP 23. Field print-out and plot control PATCH(XZ,CONTUR,1,NX,1,1,1,NZ,1,1) PLOT(XZ,P1,0.0,20.0);PLOT(XZ,W1,0.0,20.0) PATCH(CENTRE,PROFIL,1,1,1,1,1,NZ,1,1) PLOT(CENTRE,P1,0.0,0.0);PLOT(CENTRE,W1,0.0,0.0) NZPRIN=2 NCRT=1 OUTPUT(WCRT,Y,N,N,N,N,N) OUTPUT(UCRT,Y,N,N,N,N,N) TSTSWP=-1