```

PHOTON USE
p
p2
10 1

view x
norm
gr ou x 1
msg   Velocity vectors - time=1 sec
vec x 1 sh
msg
msg Press  to continue
pause
vec off;red
msg        Pressure distribution - time=1 sec
con p1 x 1 fi;.01
msg
msg Press  to continue
pause
con off;red
msg   Temperature distribution - Prandtl number 0.7:
con h1 x 1 fi;.001
msg Press  to continue
pause
con off;red
msg   Temperature distribution - Prandtl number 1.0:
con a x 1 fi;.001
msg
msg Press  to continue
pause
con off;red
msg   Temperature distribution - Prandtl number 0.1:
con b x 1 fi;.001
msg
msg Press  to see results after increase in flow rate
pause
p
p4
10 1

view x
norm
gr ou x 1
msg   Velocity vectors - time=3 sec
vec x 1 sh
msg
msg Press  to continue
pause
vec off;red
msg        Pressure distribution - time=3 sec
con p1 x 1 fi;.01
msg
msg Press  to continue
pause
con off;red
msg   Temperature distribution - Prandtl number 0.7:
con h1 x 1 fi;.001
msg Press  to continue
pause
con off;red
msg   Temperature distribution - Prandtl number 1.0:
con a x 1 fi;.001
msg
msg Press  to continue
pause
con off;red
msg   Temperature distribution - Prandtl number 0.1:
con b x 1 fi;.001
msg
msg Press e to END
enduse

GROUP 1. Run title and other preliminaries
TEXT(Laminar Flow In Pipe-Transient
TITLE
mesg(PC486/50 time last reported as appx. 1.5 min
DISPLAY
This case examines the transient flow in a pipe resulting from
an abrupt change in inlet conditions. The  uniform inflow
is imposed at the inlet, at the start of the calculation.
The pipe-wall temperature differs from the initial temperature
of the flow. Three extra variables are treated as temperatures
with different Prandtl numbers.

The development of the transient flow can be studied through
changing parameters such as geometry, flow properties and flow
rate at the inlet.
hot pipe wall
////////////////////////////
inlet   -----------------------------
---->
uniform inflow                       exit
---->
_________________________axis____________

For a grid-independent solution, smaller grid size is needed.
ENDDIS

GROUP 2. Transience; time-step specification
** Activate unsteady term in the solved equations
IREGT=1; GRDPWR(T,5,0.5,1.0)

GROUP 3. X-direction grid specification
CARTES=F

*  Write objects
RSET(D,PIPE,1.,0.01,0.5,1,0)
RSET(B,PIPEW,0,0.01,0,1.,0,0.5,11,0)

GROUP 4. Y-direction grid specification
IREGY=1; GRDPWR(Y,10,0.01,1.0)

GROUP 5. Z-direction grid specification
IREGZ=1; GRDPWR(Z,10,0.5,1.0)

GROUP 6. Body-fitted coordinates or grid distortion
GROUP 7. Variables stored, solved & named
** Solve for three extra variables, A, B AND C, treated as
temperatures with different Prandtl numbers.
SOLVE(P1,V1,W1,H1,C1,C2,C3)
NAME(C1)=A; NAME(C2)=B; NAME(C3)=C

GROUP 8. Terms (in differential equations) & devices
GROUP 9. Properties of the medium (or media)
ENUL=1.E-5;PRNDTL(H1)=0.7
PRNDTL(A)=1.0;PRNDTL(B)=0.1;PRNDTL(C)=10.0

GROUP 13. Boundary conditions and special sources

1. Wall at north boundary

WALL (PIPEW,NORTH,#1,#1,#NREGY,#NREGY,#1,#NREGZ,#1,#NREGT)
COVAL(PIPEW,W1,1.0,0.0);COVAL(PIPEW,H1,1./PRNDTL(H1),1.0)
COVAL(PIPEW,A,1.0,1.0);COVAL(PIPEW,B,10.0,1.0)
COVAL(PIPEW,C,0.1,1.0)

2. Inlet-- uniform flow

INLET(UNIFORM,LOW,#1,#1,#1,#NREGY,#1,#1,#1,#NREGT)
VALUE(UNIFORM,P1,0.1);VALUE(UNIFORM,W1,0.1)
VALUE(UNIFORM,V1,0.0);VALUE(UNIFORM,H1,0.0)
VALUE(UNIFORM,A,0.0);VALUE(UNIFORM,B,0.0)
VALUE(UNIFORM,C,0.0)

2. Outlet-- fixed pressure

PATCH(OUTLET,HIGH,#1,#1,#1,#NREGY,#NREGZ,#NREGZ,#1,#NREGT)
COVAL(OUTLET,P1,FIXVAL,0.0)
COVAL(OUTLET,V1,ONLYMS,0.0);COVAL(OUTLET,W1,ONLYMS,0.0)

GROUP 15. Termination of sweeps
LSWEEP=20
RESREF(P1)=1.E-6;RESREF(V1)=1.E-6
RESREF(H1)=1.E-6;RESREF(W1)=1.E-6
RESREF(A)=1.E-6;RESREF(B)=1.E-6;RESREF(C)=1.E-6
SPEDAT(SET,GXMONI,TRANSIENT,L,F)
GROUP 22. Spot-value print-out
NPRMON=LSWEEP;IYMON=5

GROUP 22. Spot-value print-out
IYMON=NY/2;IZMON=NZ/2;IPLTL=30

GROUP 23. Field print-out and plot control
NTPRIN=1
NZPRIN=2
PATCH(TIMPLOT1,PROFIL,1,1,1,NY,NZ-1,NZ-1,1,LSTEP)
PLOT(TIMPLOT1,W1,0.0,0.2);PLOT(TIMPLOT1,A,0.0,1.0)
PLOT(TIMPLOT1,B,0.0,1.0);PLOT(TIMPLOT1,C,0.0,1.0)
PATCH(TIMPLOT2,CONTUR,1,1,1,NY,1,NZ,1,LSTEP)
PLOT(TIMPLOT2,W1,0.0,10);PLOT(TIMPLOT2,H1,0.0,10)
PLOT(TIMPLOT2,A,0.0,10);PLOT(TIMPLOT2,B,0.0,10.0)
PLOT(TIMPLOT2,C,0.0,10)

***actdem***
xulast=.01
2. Inlet-- uniform flow Re=100
INLET(UNIFORM,LOW,#1,#1,#1,#NREGY,#1,#1,1,2)
VALUE(UNIFORM,P1,0.1);VALUE(UNIFORM,W1,0.1)
VALUE(UNIFORM,V1,0.0);VALUE(UNIFORM,H1,0.0)
VALUE(UNIFORM,A,0.0);VALUE(UNIFORM,B,0.0)
VALUE(UNIFORM,C,0.0)
3. Inlet-- uniform flow Re=1000
INLET(re1000,LOW,#1,#1,#1,#NREGY,#1,#1,3,lstep)
VALUE(re1000,P1,1.0);VALUE(re1000,W1,1.0)
VALUE(re1000,V1,0.0);VALUE(re1000,H1,0.0)
VALUE(re1000,A,0.0);VALUE(re1000,B,0.0)
VALUE(re1000,C,0.0)

idispa=1; csg1=p
selref=t; resfac=1.e-2
tstswp=-1
```