PHOTON USE
p;;;;;
up 1 0 0;vi 0.5 1 0.75
gr ou x 1;gr ou y 1;gr ou z 1
gr ou x m;gr ou y m;gr ou z m
gr ou x 1 y 1 2 z 2 2 col 2
gr ou x 6 y 1 2 z 7 7 col 2
gr ou z 4 x 1 4 y 1 3 col 6
gr ou z 6 x 2 5 y 1 3 col 6
ve y 2 sh
msg 3D SHELL-AND-TUBE HEAT EXCHANGER
msg --------------------------------
msg Velocity 1 phase:
msg Press Enter to continue
pause;vi 0 1 0
*msg 3D SHELL-AND-TUBE HEAT EXCHANGER
*msg --------------------------------
*msg Temperature distribution 1 phase:
*con 1sth y 2 sh;in 50
msg Press Enter to continue
pause
con off;red
*msg 3D SHELL-AND-TUBE HEAT EXCHANGER
*msg --------------------------------
*msg Temperature distribution 2 phase:
*con 2ndh y 2 sh;in 50
msg Press e to END
ENDUSE
>>>>>>>>>>>>>>>>>>>>>> Comment begins >>>>>>>>>>>>>>>>>>>>
#cls
DISPLAY
This case concerns 3D flow of viscous fluid on the shell side
of a heat exchanger.
Two types of false-time under-relaxation are provided via
PLANT: namely 1. global and 2. local.
For the purpose of illustration, the solution process is
divided into 3 stages, as follows:
* No relaxation for ISWEEP < 101 ,
* Global relaxation for 100 < ISWEEP < 201 ,
* Local relaxation for 200 < ISWEEP .
PLANT information :
* Data input groups used: 17, 19
* Ground groups planted : 13, 19-2, 19-3
* Headings used : SC02??, SC03??, SORC??
* Functions used : None
* Commands used : IF, REGION
ENDDIS
<<<<<<<<<<<<<<<<<<<<<<< Comment ends <<<<<<<<<<<<<<<<<<<<<
GROUP 1. Run title and other preliminaries
TEXT( Global and self-steering under-relaxatn
** FLO1 = mass-flow rate of shell fluid
REAL(FLO1);FLO1=0.1
GROUP 3. X-direction grid specification
The heat exchanger is a rectangular box, 1m high,
1m wide and 4m long. A uniform 5*3*8 grid is used,
as was done by Patankar and Spalding.
Only one half of the exchanger is included in the
calculation domain, because of the symmetry of the
geometry.
GRDPWR(X,5,1.0,1.0)
GROUP 4. Y-direction grid specification
NY=3
GRDPWR(Y,NY,0.5,1.0)
GROUP 5. Z-direction grid specification
GRDPWR(Z,8,4.0,1.0)
GROUP 7. Variables stored, solved & named
The shell-side fluid is a single-phase one, for which
five variables must be solved; only the enthalpy needs
be computed for the tube-side fluid.
SOLVE(P1,U1,V1,W1)
STORE(EPOR,NPOR,HPOR)
GROUP 8. Terms (in differential equations) & devices
TERMS(U1,Y,Y,Y,Y,Y,Y);TERMS(V1,Y,Y,Y,Y,Y,Y)
TERMS(W1,Y,Y,Y,Y,Y,Y)
GROUP 9. Properties of the medium (or media)
ENUL=10.
GROUP 11. Initialization of variable or porosity fields
FIINIT(W1)=FLO1;FIINIT(U1)=0.0;FIINIT(V1)=0.0
FIINIT(EPOR)=0.5;FIINIT(NPOR)=0.5;FIINIT(HPOR)=0.5
GROUP 13. Boundary conditions and special sources
** West boundary; shell fluid inlet ; 2 cells in west wall
PATCH(INLET1,CELL,1,1,2,3,2,2,1,1000)
COVAL(INLET1,P1,FIXFLU,FLO1/2.0)
** East boundary; shell fluid outlet; 2 cells in east wall
PATCH(OUTLET1,EAST,NX,NX,2,3,NZ-1,NZ-1,1,1000)
COVAL(OUTLET1,P1,FIXP,0.0)
** Baffle 1 at NZ=3
PATCH(BAFFLE1,HIGH,1,NX-1,1,NY,3,3,1,1000)
COVAL(BAFFLE1,W1,FIXVAL,0.0)
** Baffle 2 at NZ=5
PATCH(BAFFLE2,HIGH,2,NX,1,NY,5,5,1,1000)
COVAL(BAFFLE2,W1,FIXVAL,0.0)
GROUP 15. Termination of sweeps
LSWEEP=400
GROUP 16. Termination of iterations
LITER(P1)=100
GROUP 17. Under-relaxation devices
NAMSAT=MOSG
RG(1)=ENUL
PLANTBEGIN
** Global under-relaxation
RG(2)=AMIN1(XULAST/FLOAT(NX),YVLAST/FLOAT(NY),$
ZWLAST/FLOAT(NZ))/$
AMAX1(U1,:FLO1:/2.)
REGION(1,1,2,3,2,2)
IF(ISWEEP.GT.100.AND.ISWEEP.LE.200)
DTFALS(U1)=RG(2)
REGION(1,1,1,1,1,1)
IF(ISWEEP.GT.100.AND.ISWEEP.LE.200)
>>>>>>>>>>>>>>>>>>>>>> Comment begins >>>>>>>>>>>>>>>>>>>>
Global under-relaxation is introduced by PLANTed
codings for DTFALS(U1) at the start of each sweep. It
is assumed to be equal to the smallest of the cell
sizes divided by the largest of inlet mass flux
velocity and local velocity magnitude normal to the
inlet plane. It is applied over the whole domain for
the velocity in question IF isweep is greater than 100
but less or equal than 200.
Here and for next two statemnts, command REGION with
unity arguments is used to economize the operations
needed for equivalences.
<<<<<<<<<<<<<<<<<<<<<<< Comment ends <<<<<<<<<<<<<<<<<<<<<
DTFALS(V1)=RG(2)
REGION(1,1,1,1,1,1)
IF(ISWEEP.GT.100.AND.ISWEEP.LE.200)
>>>>>>>>>>>>>>>>>>>>>> Comment begins >>>>>>>>>>>>>>>>>>>>
The above settings do for DTFALS(V1) what has been done
for DTFALS(U1) above.
<<<<<<<<<<<<<<<<<<<<<<< Comment ends <<<<<<<<<<<<<<<<<<<<<
DTFALS(W1)=RG(2)
REGION(1,1,1,1,1,1)
IF(ISWEEP.GT.100.AND.ISWEEP.LE.200)
>>>>>>>>>>>>>>>>>>>>>> Comment begins >>>>>>>>>>>>>>>>>>>>
The above settings do for DTFALS(W1) what has been done
for DTFALS(U1).
<<<<<<<<<<<<<<<<<<<<<<< Comment ends <<<<<<<<<<<<<<<<<<<<<
** Local self-steering under-relaxation
PATCH(RELAX,PHASEM,1,NX,1,NY,1,NZ,1,1)
CO=1./TFAL
COVAL(RELAX,U1,GRND,SAME)
IF(ISWEEP.GT.200)
CO=1./TFAL
COVAL(RELAX,V1,GRND,SAME)
IF(ISWEEP.GT.200)
CO=1./TFAL
COVAL(RELAX,W1,GRND,SAME)
IF(ISWEEP.GT.200)
>>>>>>>>>>>>>>>>>>>>>> Comment begins >>>>>>>>>>>>>>>>>>>>
Local self-steering under-relaxation is introduced
through the sources of momentum for the whole domain
defined by PATCH named RELAX, which TYPE is PHASEM,
VALue is SAME, COefficient, which is set to reciprocal
of false-time step. It is applied for each sweep
greater than 200.
<<<<<<<<<<<<<<<<<<<<<<< Comment ends <<<<<<<<<<<<<<<<<<<<<
** Local fals-time step
STORE(TFAL);OUTPUT(TFAL,Y,Y,Y,Y,Y,Y)
TFAL=1/(SQRT(U1**2+W1**2+V1**2)/$
AMIN1(DXU2D*1,AMIN1(DYV2D*1,DZ*1))+$
RG(1)/AMIN1(DXU2D*1,AMIN1(DYV2D*1,DZ*1))**2)
IF(ISWEEP.GT.200)
>>>>>>>>>>>>>>>>>>>>>> Comment begins >>>>>>>>>>>>>>>>>>>>
The reciprocal of local self-steering false-time step
is set to the local velocity vector magnitude divided
by smallest distance between walls of continuity cell
in question plus local diffusivities, i.e. kinematic
viscosities, divided by the smallest distance squarred.
The variable TFAL, false-time, is provided to assist
the computations. It is calculated right at the start
of each IZ-slab for all sweeps greter than 200 and can
be used to monitor the variation of local magnitudes of
false-time steps.
<<<<<<<<<<<<<<<<<<<<<<< Comment ends <<<<<<<<<<<<<<<<<<<<<
PLANTEND
GROUP 19. Data communicated by satellite to GROUND
GROUP 20. Preliminary print-out
GROUP 21. Print-out of variables
Print-out of porosities is suppressed.
OUTPUT(EPOR,N,N,N,N,N,N);OUTPUT(NPOR,N,N,N,N,N,N)
OUTPUT(HPOR,N,N,N,N,N,N)
GROUP 22. Spot-value print-out
IXMON=NX-2;IYMON=2;IZMON=4
GROUP 23. Field print-out and plot control
IPLTL=LSWEEP;IPROF=1;ORSIZ=0.4;XZPR=T;NPLT=1
TSTSWP=-1
dmpstk=t
DISTIL=T
EX(P1)=3.711E+02; EX(U1)=3.000E-01; EX(V1)=2.753E-02
EX(W1)=3.253E-01; EX(TFAL)=2.757E-03
LIBREF=613
STOP