photon use
  p
  parphi
 
 
  msg the grid. Press return to see the temperature field
  gr ou z 1
  gr ou z m
  gr y m
  pause
  gr off
  red
  gr ou x 1
  gr ou z 1
  msg Temperature contours. Press return to see the pressure field
  do kk=1,20
    con h1 z kk fi;0.01
  enddo
  gr ou z m
  pause
  con off
  red
  msg pressure contours on an axial plane; Press return for vectors
  con p1 x 1 fi;0.01
  gr ou z m
  pause
  msg velocity vectors on plane between fins.
  msg Press e to end. Other wise enter command
  con off
  red
  vec x m sh
  gr ou z m
  enduse
 
    GROUP 1.  Run title and other preliminaries
TEXT(Internally-Finned Pipe; Laminar   
TITLE
  DISPLAY
  The radial fins are continuous, thin, uniformly spaced.
  Fluid enters the pipe with uniform velocity and temperature;
  A constant temperature is prescribed for both fins and pipe wall.
 
                 x--->    Pipe wall (1/48 radian segment)
                 ******    /
            Fin |       ***                   Constant temperature
      ^       \ |           **                         |
      |        \|            /         ^       .-.-----|-----.--
      |         |                      |r    /     \           \
      r         |         /            |   -|-->    |           |
                                           -|-->    |           |
       Symmetry |      /--Symmetry    Fixed  \     /           /
       plane \            plane       mass,    `-'-----------'--
              \ |   /                 momentum and  z---->
               \                      enthalpy fluxes
                |/
  Note that the above sketch suggests the the fin projects only 
  part of the way towards the axis; but the patch representing
  the fin wall in fact  extends to the axis.
  This is altogther a poor representation of a finned tube, 
  no simulation is effected of the reduction in surface 
  temperature with diminishing radius resulting from the finite
  conductivity of the fin material.
  This library case should be replaced by one which is more 
  realistic.
  
  The Q1 file contains PHOTON USE commands.
  
    The locally-defined variables are as follows:
 
      NFIN           number of fins
      DPIP           pipe diameter
      TWAL           wall temperature
      TIN            inlet temperature
      WIN            inlet velocity.
  ENDDIS
 
REAL(WIN,DPIP,TWAL,TIN,REYNLDS);INTEGER(NFIN)
NFIN=24; WIN=0.1; DPIP=0.08; TWAL=25.0; TIN=20.0
 
    GROUP 2. Transience; time-step specification
    GROUP 3. X-direction grid specification
CARTES=F; IREGX=1; GRDPWR(X,10,3.1416/NFIN,1.2)
 
    GROUP 4. Y-direction grid specification
IREGY=1; GRDPWR(Y,10,0.5*DPIP,-2.0)
 
    GROUP 5. Z-direction grid specification
PARAB=T; IREGZ=1; GRDPWR(Z,20,0.1,1.0)
 
    GROUP 6. Body-fitted coordinates or grid distortion
    GROUP 7. Variables stored, solved & named
SOLVE(P1,W1,U1,V1,H1)
 
    GROUP 8. Terms (in differential equations) & devices
TERMS(H1,N,P,P,P,P,P)
 
 
    GROUP 9. Properties of the medium (or media)
PRNDTL(H1)=0.70;REYNLDS=WIN*YVLAST*2.0/ENUL
REYNLDS
 
    GROUP 13. Boundary conditions and special sources
 
   ** Uniform velocity and temperature at the inlet
INLET(IN,LOW,#1,#NREGX,#1,#NREGY,#1,#1,1,1)
VALUE(IN,P1,1.0*WIN);VALUE(IN,W1,WIN);VALUE(IN,H1,TIN)
 
   ** Constant temperature at fin surface.
WALL (FINWALL,WEST,#1,#1,#1,#NREGY,#1,#NREGZ,1,1)
COVAL(FINWALL,W1,1.0,0.0);COVAL(FINWALL,V1,1.0,0.0)
COVAL(FINWALL,H1,1.0,TWAL)
 
   ** Constant temperature at pipe wall.
WALL (PIPEWALL,NORTH,#1,#NREGX,#NREGY,#NREGY,#1,#NREGZ,1,1)
COVAL(PIPEWALL,W1,1.0,0.0);COVAL(PIPEWALL,U1,1.0,0.0)
COVAL(PIPEWALL,H1,1.0,TWAL)
 
    GROUP 14. Downstream pressure for PARAB=.TRUE.
    GROUP 15. Termination of sweeps
LITHYD=10;SELREF=T;RESFAC=0.01
 
    GROUP 16. Termination of iterations
LITER(U1)=10;LITER(V1)=10;LITER(W1)=10
    GROUP 17. Under-relaxation devices
RELAX(U1,FALSDT,1.0);RELAX(V1,FALSDT,1.0);RELAX(W1,FALSDT,1.0)
 
    GROUP 22. Spot-value print-out
TSTSWP=LITHYD;IPLTL=LITHYD;IYMON=NY/2+1;IXMON=NX/2;UWATCH=T
 
    GROUP 23. Field print-out and plot control
IXPRL=NX-1; NXPRIN=2; NYPRIN=2; NZPRIN=5
PATCH(EXIT,CONTUR,1,NX,1,NY,NZ,NZ,1,1);COVAL(EXIT,H1,0.0,10.0)
IDISPA=1;IDISPB=1;IDISPC=NZ