GROUP 1. Run title and other preliminaries TEXT(Ricou's Jet In Cylindrical Chamber TITLE real(winj,rhoinj,walvel,reyno,jetdiam,denrat) rhoinj=1.0; winj=50.0 DISPLAY F Ricou (London University PhD thesis 1959) injected gases into a porous-walled cylindrical chamber with a circular exit opposite the injection orifice. He varied the inflow rate of air through the porous wall until the pressure in the chamber equalled that outside, and took this to be the rate of entrainment of air into jet. When the flow was turbulent, he found that the rate of entrain- ment per unit length equalled 0.32 times the mass-injection rate divided by the nozzle diameter, if the injected fluid had the same density as the surrounding fluid. Please press RETURN to continue readvdu(nphi,int,nphi) When the densities differed he found that the 0.32 factor should be replaced by: 0.32 * (surrounding-fluid density/injected-fluid density)**0.5 This Q1 file causes PHOENICS to simulate the conditions of the experiment. The Reynolds number and density ratio can be varied. The Prandtl mixing-length model of turbulence is used, with the low-Reynolds-Number modification activated by IENUTA=6 . PHOTON commands are supplied. ENDDIS PHOTON USE p phi up z gr ou x 1 msg contours of axial velocity con w1 x 1 fi;0.001;pause;con off; red msg contours of concentration of injected material con a x 1 fi;0.001;pause;con off;red msg enut contours con enut x 1 fi;0.001;pause;con off;red msg velocity vectors vec x 1 sh;pause;con off;vec off;red msg streamlines stre 2d x 1 sh;int 20 enduse GROUP 3. X-direction grid specification ** Activate polar coordinate system CARTES=F; XULAST=0.01 GROUP 4. Y-direction grid specification GRDPWR(Y,40,4.5*0.0254,1.0) JETDIAM=0.2*YVLAST GROUP 5. Z-direction grid specification GRDPWR(Z,40,12.75*0.0254,1.0) GROUP 7. Variables stored, solved & named SOLVE(P1,V1,W1,C1); STORE(ENUT,LEN1); NAME(C1)=A GROUP 9. Properties of the medium (or media) RHO1=1.0; ENUL=1.E-5; PRNDTL(A)=0.7; PRT(A)=0.7 REYNO=WINJ*JETDIAM/ENUL mesg(reynolds number is :reyno: if ok, press return mesg(otherwise insert desired number READVDU(REYNO,REAL,REYNO) WINJ=REYNO*ENUL/JETDIAM REYNO DENRAT=RHOINJ/RHO1 mesg( Ratio of injected to surrounding density is :denrat: mesg( If ok, press return, otherwise insert desired number... READVDU(denrat,REAL,denrat) RHOINJ=DENRAT*RHO1 DENRAT ENUT=0.016*WINJ*JETDIAM ** settings for the Prandtl Mixing Length Model EL1=MIXLENJET; ENUT=MIXLEN; DWDY=T ** EL1A = mixing-length constant for mixing-layer zone EL1A=0.05 EL1B = '' '' '' for jet zone EL1B=0.075 EL1C = velocity fraction for jet-width calculation EL1C=0.01 EL1D = free-stream velocity for jet-width calculation EL1D=0.0 EL1E = jet-discharge velocity ( mixing-length constant is switched from EL1A to EL1B, when centre-line velocity falls below EL1E ) EL1E=WINJ ** settings for the Local Reynolds Number Modification IENUTA=6; ENUTA=0.2; ENUTB=4.0 GROUP 11. Initialization of variable or porosity fields PATCH(INITIAL,INIVAL,1,1,1,NY/5,1,NZ,1,1) COVAL(INITIAL,W1,0.0,WINJ); COVAL(INITIAL,A,0.0,1.0) FIINIT(ENUT)= 0.016*WINJ*JETDIAM GROUP 13. Boundary conditions and special sources PATCH(IN,LOW,1,1,1,NY/5,1,1,1,1) COVAL(IN,P1,FIXFLU,WINJ*RHO1); COVAL(IN,W1,ONLYMS,WINJ) COVAL(IN,A,ONLYMS,1.0); COVAL(IN,V1,ONLYMS,0.0) ** the imposed velocity at the cylindrical wall WALVEL=(0.32/8)*(winj*jetdiam/yvlast)*denrat**(-0.5) PATCH(WALL,NORTH,1,1,NY,NY,1,NZ,1,1) COVAL(WALL,P1,FIXFLU,RHO1*WALVEL); COVAL(WALL,W1,ONLYMS,0.0) COVAL(WALL,A,ONLYMS,0.0) PATCH(OUTLET,HIGH,1,1,1,4*NY/5,NZ,NZ,1,1) COVAL(OUTLET,P1,1.E5,0.0); COVAL(OUTLET,A,ONLYMS,SAME) COVAL(OUTLET,V1,ONLYMS,0.0); COVAL(OUTLET,W1,ONLYMS,0.0) GROUP 15. Termination of sweeps LSWEEP=100; SELREF=T; RESFAC=0.01 GROUP 17. Under-relaxation devices RELAX(W1,FALSDT,0.001); RELAX(V1,FALSDT,0.1); RELAX(ENUT,LINRLX,0.5) GROUP 22. Spot-value print-out NPRMON=20; IYMON=5 GROUP 22. Spot-value print-out IYMON=19; IZMON=10; TSTSWP=-1; itabl=1 GROUP 23. Field print-out and plot control NYPRIN=NY/10; NZPRIN=NZ/10; NPLT=1 PATCH(EXIT,PROFIL,1,1,1,NY,NZ-1,NZ-1,1,1) PLOT(EXIT,W1,0.0,0.0); PLOT(EXIT,A,0.0,0.0) PATCH(PIPE,CONTUR,1,1,1,NY,1,NZ,1,1) PLOT(PIPE,W1,0.0,10.0); PLOT(PIPE,A,0.0,10.0) LIBREF=281 **END OF LIBRARY CASE 281