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 -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 -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.