DISPLAY
 
 
  WAKE - SLOW JET ENTERING FAST-MOVING SURROUNDING
 
  2-dimensional (y-z), Cartesian, steady, parabolic
 
 
  This case is a modified library case 154 in which a self-
  preserving free turbulent round jet is considered; instead
  of a jet entering stagnant surrounding in this case
  surrounding is moving with the speed greater that that of
  a jet. A wake is like a 'negative jet';ie the velocity
  near the axis is less than that in the surrounding stream.
 
  The k-l turbulence model is used in this example.
 
  enddis
 
  PHOTON USE
  p
  parphi
 
 
 
 
  msg                        TURBULENT WAKE
  msg
  msg        Velocity vectors:
  set vec ref 30.
  vec x 1 sh
  msg            -
  msg Press  to continue
  pause
  vec off;red
  msg        Axial velocity contours:
  con wcrt x 1 fi; 0.01
  msg            -
  msg Press  to continue
  pause
  con off;red
  msg        Temperature contours:
  con temp x 1 fi;0.01
  msg
  msg Press  to continue
  pause
  con off;red
  msg        eddy-viscosity (enut) contours:
  con enut x 1 fi;0.01
  msg
  msg Press e to END
  enduse
 
    GROUP 1. Run title and other preliminaries
TEXT(Slow Jet Entering Fast-Moving Surr
TITLE
mesg(PC486/50 time last reported as 1.min
  The self-preserving free turbulent round jet is considered. This
  flow, like the plane jet (see cases 150,151 and 152), becomes
  self-similar after a certain development region.In this case, the
  description of self-similarity given for the plane jet is equally
  applicable here, except that the centre-line velocity and the
  maximum temperature excess decay as z to the power minus one.
 
  The calculation details are the same as those given for the plane
  jet,except of course that the solution domain is now
  axisymmetric.
 
  In this case, the Prandtl mixing-length turbulence model is used
  and the mixing-length Lm is taken to be uniform across the jet
  and equal to 0.07 times the width of the turbulent region. This
  width is defined as the point at which the w-velocity equals 1%
  of the maximum velocity difference across the layer. The
  turbulent Prandtl number is set equal to 0.5.
 
   GXLEN and GXENUT are used for this case.
 
    The locally-defined variables are as follows:
 
     WJET     Jet velocity at the inlet                 (m/s)
     REYNO    Reynolds number
     DIAM     The diameter of the jet nozzle            (m)
     TJET     The jet temperature at the inlet          (C)
     TFREE    The temperature of the free stream        (C)
 
 
REAL(WJET,REYNO,DIAM,TJET,FRA,TFREE,wfree)
REYNO=5.E4;DIAM=0.1;WJET=1.50;TJET=1.0;TFREE=0.0;wfree=7.5
 
    GROUP 3. X-direction grid specification
CARTES=F;XULAST=0.1
 
    GROUP 4. Y-direction grid specification
NY=20;YVLAST=DIAM
YFRAC(1)=-20;YFRAC(2)=1.0/20.0
   *** Grid expansion
AZYV=1.0;ZWADD=0.25
 
    GROUP 5. Z-direction grid specification
PARAB=T
  ** The change in z-direction step size is supplied
     in group 5 of GROUND by setting AZDZ=PROPY;
     the parameter, DZW1 is set in group 19 below for
     this purpose.
NZ=20;AZDZ=PROPY
    GROUP 7. Variables stored, solved & named
SOLVE(P1,V1,W1,H1);NAME(H1)=TEMP;STORE(ENUT)
    GROUP 8. Terms (in differential equations) & devices
DIFCUT=0.0;TERMS(TEMP,N,Y,Y,Y,Y,Y)
    GROUP 9. Properties of the medium (or media)
ENUL=WJET*DIAM/REYNO;PRT(TEMP)=0.5
  **Select formula for the length scale supplied in GXLEN
    by setting EL1=MIXLENJET, for which the parameters, EL1A,
    EL1C, EL12, EL2B are set in group 19.
EL1=MIXLENJET
  **Selet Prandtl mixing-length formula supplied in GXENUT for
    the turbulent kinematic viscosity.
ENUT=MIXLEN
    GROUP 13. Boundary conditions and special sources
    1. Outer Boundary-- free stream
PATCH(HIGHY,NORTH,1,1,NY,NY,1,NZ,1,1)
COVAL(HIGHY,P1,1.0E4,0.0)
COVAL(HIGHY,W1,ONLYMS,wfree)
COVAL(HIGHY,V1,ONLYMS,0.0)
COVAL(HIGHY,TEMP,ONLYMS,TFREE)
 
PATCH(frZZLE,LOW,1,1,16,ny,1,1,1,1)
COVAL(frZZLE,P1,FIXFLU,RHO1*wfree);COVAL(frZZLE,W1,ONLYMS,wfree)
COVAL(frZZLE,TEMP,ONLYMS,Tfree)
    2. Inlet Boundary-- uniform flow
 
PATCH(NOZZLE,LOW,1,1,1,15,1,1,1,1)
COVAL(NOZZLE,P1,FIXFLU,RHO1*WJET);COVAL(NOZZLE,W1,ONLYMS,WJET)
COVAL(NOZZLE,TEMP,ONLYMS,TJET)
    GROUP 14. Downstream pressure for PARAB=T
IPARAB=1
    GROUP 16. Termination of iterations
LITHYD=30
RESREF(P1)=1.E-6;RESREF(V1)=1.E-5;RESREF(W1)=1.E-5
RESREF(TEMP)=1.E-5
    GROUP 17. Under-relaxation devices
RELAX(V1,FALSDT,10.0);RELAX(W1,FALSDT,10.0)
RELAX(TEMP,FALSDT,10.0)
    GROUP 18. Limits on variables or increments to them
VARMIN(V1)=-1.E3;VARMAX(V1)=1.E3
    GROUP 19. Data communicated by SATELLITE to GROUND
  ** Parameter for grid expansion
DZW1=0.3
  ** Select strain-rate for use in Mixing-Length model
DWDY=T
  ** Prandtl=mixing-length constants
EL1A=0.07;EL1C=0.1
EL2A=4.0 ;EL2B=6.0
    GROUP 22. Monitor print-out
IZMON=NZ/2;IYMON=NY/2;ITABL=1;NPLT=1;IPLTL=LITHYD;TSTSWP=-1
    GROUP 23. Field print-out and plot control
ORSIZ=0.4;PATCH(IZEQNZ,PROFIL,1,1,1,NY,NZ,NZ,1,1)
PLOT(IZEQNZ,W1,0.0,0.0);PLOT(IZEQNZ,TEMP,0.0,0.0)
PLOT(IZEQNZ,ENUT,0.0,0.0)
NZPRIN=NZ
idispa=1
    GROUP 24. Dumps for restarts