PROBLEM DEFINITION
This problem examines the flow of a two-phase mixture of Newtonian fluids within a sequence of chambers that is found in T-By pass distillation plates. The light phase is injected from holes located throughout the plate, while the dense phase is introduced from above. The mixing of the two phases, under certain conditions, produces a stable froth with high mass transfer rates. We are examining non-steady state flow. The geometry and initial/boundary conditions are illustrated below:
EXECUTABLE AND INPUT FILE
Input file (PROB.INP)
Windows 3.x/9x/ME/2000/NT Executable (PCTby.EXE)
Obtain both files in a compressed package (PCTby.ZIP)
SAMPLE RESULTS
Movies for dense phase
Volume fraction contours, for a 5 chamber simulation (movie).
Volume fraction contours, for a 2 chamber simulation (movie).
Volume fraction contours, for a 1 chamber simulation, low flow rate (movie).
Volume fraction contours, for a 1 chamber simulation, high flow rate (movie).
Pictures
Volume fraction contours for the dense phase at t=0.5s (generated using CONTOUR):
Velocity vector field for the dense phase at t=0.5s (generated using ARROW):
Velocity vector field for the light phase at t=0.5s (generated using ARROW):
Sample results input file
(PROB.INP)
*
*
===[ PARAMETER'S FILE FOR TFLOW ; TRANSIENT T-PASS
]==
*
===[
PROBLEM PARAMETRES
]===============================================
Height of cavity, Angle of
inclination against horiz. [HEIGHT,THETA]
0.025d0, 0d0
Gap
length of liquid water, and two-phase exit (% of sides) [PINW,POUT]
25,25
Number
of channels [NCH]
5
Lengths of each channel ("NCH"
numbers) [WCH]
5*0.01
Gap
length of air entry (% of sides) ("NCH" numbers) [PINA]
5*25
Internal (right) wall height for
each channel ("NCH"-1 numbers) [HCH]
4*0.01
Inlet
velocity of liquid water and air [UINW, UINA]
0.1,0.1
Initial volume fraction of liquid
phase in cavity [R1INIT]
0.001
Interphase friction coefficient
[FCOEF]
100d0
===[
GRID PARAMETERS
]==================================================
Number
of cells in X- and Y- direction [NI,NJ]
102,
32
===[
TIME PARAMETERS
]==================================================
Steady
state flow ?
[STEADY]
.F.
Number
of time steps
[NT]
500
Time
step size
[DT]
0.01
===[
DEPENDENT VARIABLES
]==============================================
Solve
for U- and P- equations ? [INCALU]
.T.
Solve
for R-equations ? [INCALR]
.T.
===[
THERMO-PHYSICAL PROPERTIES
]=======================================
Material Density for both phases
[RHO1,RHO2]
1D3,
1D0
Laminar fluid viscosity for both
phases
[VISC1,VISC2]
1D-3,
1d-5
===[
TERMINATION CRITERIA FOR ITERATIONS
]==============================
Maximum number of iterations per
time step
[MAXIT]
500
Maximum acceptable value of residuals
[SORMAX]
5.D-05
===[
UNDER-RELAXATION
]=================================================
Under-relaxation factor for U- V-
and P- equations
[URFU,URFV,URFP]
0.2D0,
0.2D0, 0.075D0
Under-relaxation factor for
R-equation
[URFR]
0.9D0
False
time step for U- and V- equations? [FALSDTU, FALSDTV]
.F., .F.
False
time step size for U- and V- equations [DTFALSU,
DTFALSV]
0.1D0,
0.1D0
Under-relaxation factor for DU-
and DV- correction
[URFDU, URFDV]
1.0D0,
1.0d0
===[
COORDINATES OF FIXED PRESSURE POINT
]=============================
I,J index of location where pressure is fixed [IPREF,JPREF]
2,2
===[
EQUATION SOLVER SELECTION
]========================================
Solver
selection for U-, V- and P- equations [ISLVU,ISLVV,ISLVP]
2,2,2
Solver
selection for R-equations [ISLVP]
2
Constant used by SIM solver
[ALPHA]
0.8D0
Weight
terms of PP-equation with phase Density? [WEIGHT]
.t.
===[
TERMINATION CRITERIA FOR EQUATION SOLVER
]=========================
Number
of line iterations for U-, V- and P- equations [LITERU,LITERV,LITERP]
3, 3,
3
Number
of application of line iteration for R-equation [LITERR]
2
===[
INPUT-OUTPUT PARAMETERS
]==========================================
I,J index of monitoring location [IMON,JMON]
5,2
Iteration Index for residual and
field printout
[NITRES,NITPRI]
100,
10000
Time
Index for field printout [NSTPRI]
1
Read
IN initial field
[INREAD]
.T.
Name
of restart file
[RSTFIL]
RESTART.
Copy
OUT FINAL field
[INWRIT]
.T.
Name
of SAVE file
[SAVFIL]
RESTART.
Name
of main output file
[OUTFIL]
RUN.OUT