PROBLEM DEFINITION
This problem examines the region downstream of a sudden expansion. The flow is turbulent, and we are considering axisymmetric geometry. Turbulence is resolve with a Large Eddy Simulation; subgrid turbulence is parameterized using a two-parameter k-e model. The geometry is shown below:
EXECUTABLE AND INPUT FILE
Input file (PROB.INP)
Windows 3.x/9x/ME/2000/NT Executable (PCTube_T.EXE)
Obtain both files in a compressed package (PCTube_T.ZIP)
SAMPLE RESULTS
Simulations
Computational Grid (generated using CONTOUR):
Velocity vector field (generated using ARROW):
Streamlines (generated using ARROW):
V-Velocity field contours (generated using CONTOUR):
U-Velocity field contours (generated using CONTOUR):
V-Velocity field contours (generated using CONTOUR):
Turbulent kinetic energy field contours (generated using CONTOUR):
Effective viscosity field contours (generated using CONTOUR):
Sample results input file
(PROB.INP)
*
*
===[ PARAMETER'S FILE FOR TUBE
]=====================================
*
===[
CARTESIAN / CYLINDRICAL COORDINATE SYSTEM
]=======================
Define
coordinate system [ POLAR ]
.TRUE.
===[
GRID POINTS
]=====================================================
Number
of cells in x-direction [ NI
]
40
Number
of cells in y-direction [ NJ
]
40
===[
DIMENSIONS OF TUBE
]==============================================
Length
of tube [ ALTOT ]
0.24
Radius
of tube [ RLARGE ]
0.0123825
Location of abrupt expansion
[ JSTEP ]
5
===[
EXPANSION FACTORS FOR GRID
]======================================
Expansion factor in X-direction
[ FEXPX ]
1.1
Expansion factor in Y-direction
[ FEXPY ]
1.0
===[
COORDINATES OF MONITORING POINT
]=================================
Axial
monitoring location [ IMON ]
5
Radial
or Vertical monitoring location [ JMON
]
5
===[
PROGRAM CONTROL PARAMETERS
]======================================
Maximum number of iterations
[ MAXIT ]
1000
Maximum residual [ SORMAX ]
0.005
Index
for field printout [ INDPRI ]
1000
===[
DEPENDENT VARIABLES
]=============================================
Solve
for u-equation [ INCALU ]
.true.
Solve
for v-equation [ INCALV ]
.true.
Solve
for p'-equation [ INCALP ]
.true.
Solve
for t-equation [ INCALT ]
.false.
Solve
for k-equation [ INKALK ]
.TRUE.
Solve
for œ-equation [ INKALD ]
.TRUE.
Update
fluid parameters [ INPRO ]
.true.
===[
NUMBER OF SWEEPS FOR ALL VARIABLES
]==============================
Number
of application of line iteration for u-equation [
LITERU ]
2
Number
of application of line iteration for v-equation [
LITERV ]
2
Number
of application of line iteration for p'-equation [
LITERP ]
5
Number
of application of line iteration for T-equation [
LITERT ]
2
Number
of application of line iteration for k-equation [
LITERK ]
2
Number
of application of line iteration for œ-equation [
LITERE ]
2
===[
UNDER-RELAXATION
]================================================
Under
relaxation factor for u-velocity [ URFU
]
0.5
Under
relaxation factor for v-velocity [ URFV
]
0.5
Under
relaxation factor for pressure correction [ URFP
]
0.25
Under
relaxation factor for temperature [ URFT
]
0.7
Under
relaxation factor for energy dissipation [ URFE
]
0.7
Under
relaxation factor for turbulence energy [ URFK
]
0.7
Under
relaxation factor for viscosity [ URFVIS
]
0.7
===[
COORDINATES OF FIXED PRESSURE POINT
]=============================
Axial
fixed-pressure location index [ IPREF
]
2
Radial
or Vertical fixed-pressure location index [ JPREF
]
2
===[
FLUID PROPERTIES
]================================================
Fluid
density at inlet of calculation domain [ DENSIT
]
998.2
Laminar
fluid viscosity [ VISCOS ]
0.9832E-3
Laminar Prandtl number [ PRANDT
]
1.0
===[
CONSTANTS OF TURBULENCE MODEL K-E
]===============================
Constant of turbulence model
[ CMU ]
0.09
Constant of turbulence model
[ CD ]
1.0
Constant of turbulence model
[ C1 ]
1.44
Constant of turbulence model
[ C2 ]
1.92
Von
Karman constant [
CAPPA ]
0.4187
Integration constant of
turbulence model [ ELOG ]
9.793
Constant of turbulence model in
k-equation [ PRTE ]
1.0
Constant of turbulence model in
e-equation [ PRED ]
1.3
Constant of turbulence model in
t-equation [ PRT ]
0.9
===[
GET INFO FOR BOUNDARY CONDITIONS
]================================
Axial
velocity at inlet of flow domain [ UIN
]
0.416
Turbulence intensity factor at
inlet of flow domain [ TURBIN
]
0.03
Length
scale factor at inlet of flow domain [ ALAMDA
]
0.005
===[
SOLVER SELECTION
]================================================
Solver
for u-velocity equations [ ISLVU
]
1
Solver
for v-velocity equations [ ISLVV
]
1
Solver
for pressure correction equationn [ ISLVP ]
1
Solver
for temperature equations [ ISLVT
]
1
Solver
for energy dissipation equations [ ISLVE
]
1
Solver
for turbulence energy equations [ ISLVK
]
1
Constand used by S.I.M. Solver [ ALPHA ]
0.8
===[
FILING SYSTEM
]===================================================
Name
of main output file [ OUTFIL
]
TUBE.OUT
Read
IN flow field [ INREAD ]
.FALSE.
PHIDA.
Copy
OUT flow field [ INWRITE ]
.TRUE.
PHIDA.
Generate PLOT file [ INPLOT ]
.TRUE.
Generate Pressure Contour Lines
[ INPRES ]
.TRUE.
Generate Temperature Contour
lines [ INTEMP ]
.FALSE.