case |
Grid |
Description
of the flow |
Results |
Comments |
#0 |
-
3-D
-
Not uniform
-
Not cartesian
|
No description
|
No results
|
-
This grid is just a test, it is not a physical case. We wanted
to precise it but...
-
Grid too ambitious
-
Too many cells
-
Not enough memory
-
Difficulties appear to obtain compatible
cells in the interface
-
No simulation
|
#1 |
-
2-D 50*120
cells
-
Cartesian-symetric
-
Uniform in the water jet
-
Non uniform anywhere else
|
Water jet in air
Unsteady and viscous model
VOF method
Time step : 0.001 s
Initial condition :
-
Water jet with a 1 mm radius and a 30 cm length at 0.1 m/s
-
15 cm wide air inlet at 0.001 m/s
Boundary conditions :
-
Velocity inlet for water / air
-
Symmetry on the water jet axis and on the other lateral face
-
Outflow for water / air
|
No results
|
-
Reversed flows appear
-
Calculation do not converge after the second time step
|
#2 |
|
Water jet in air
Unsteady and viscous model
VOF method
Time step : 0.001 s
Initial condition :
-
Water jet with a 5 mm radius
and a 10 cm length at 0.1 m/s
-
5cm wide air
inlet at 0.001 m/s
Boundary conditions :
-
Velocity inlet for water / air
-
Symetry on the water jet axis and on the other lateral face
-
Pressure outlet for water /
air
|
No Results |
-
We drew this grid in order to know if the failure of the
convergence was due to the shape of the grid (huge ratio length / width
in the previous grid)
-
Reversed flows appear
-
Calculation do not converge after the second time step
|
#3 |
Same grid as case #2
|
-
Water-jet in engine-oil
-
Same conditions as case #2
|
Results after 0.126 s :
Pressure & phase
|
-
The goal of this case is to know if the results are better
if we use two fluids having the same density range.
-
We did not continue calculation because the grid was not
thin enough within the water and was too thin far from the jet.
|
#4 |
Same grid as case #1
|
-
Water jet in engine-oil
-
Same conditions as case #1
|
Results after 3 s :
Pressure & phase
|
-
A kind of drop but there is no break even after three seconds.
-
The pressure is uniform. Nothing in the pressure repartition
can make us forecast a break.
|
#5
|
2-D 40*100
cells
Cartesian-symetric
Uniform in the water jet
Not uniform elsewhere
|
Water jet in engine-oil
Unsteady and viscous model
VOF method
Time step : 0.001 s
Iintial cindition :
-
Water jet with 2 mm radius and 10 cm lengh at 0.1 m/s
-
5 cm wide engine-oil inlet at 0.001 m/s
Boundary conditions :
-
Velocity inlet for water / engine-oil
-
Symetry on the water jet axis and on the other lateral face
-
Pressure outlet for water / engine-oil
|
Results after 5 s :
Pressure & phase
|
-
Same comments as the previous case
|
#6
|
Same grid as case #5
|
We have decreased the viscosity
of the water-liquid to 1E-10 kg/m-s (initialy equal to 1.003 E-3)
with the same conditions as case #5. |
Results after 0.8 s :
Pressure & phase
|
-
The goal of this case is to try an unviscid calculation with
a viscous model because we could not use the unviscid model.
-
The results are not really convincing
|
#7
|
Same grid as case #5
|
We have decreased the viscosity of
the engine-oil to 1E-5 kg/m-s (initaily equal to 1.06 kg/m-s)
We have decreased the viscosity of
the water-liquid to 1E-5 kg/m-s
We have patched the initial water-jet
with
an alternating static pressure in order to try
to disturb the flow.
The other conditions are the same as case #5.
|
Results after 0.5 s :
Pressure & phase
|
-
The results are completely strange.
-
No use to go further.
|
#8 |
Same grid as case #5 |
-
Water-jet in air
-
The conditions are the same as case
#5 with a time step equal to 0.0001s
|
Results after 3 s
Pressure & phase |
-
Test with a smaller time step
-
The calculation converge
-
The pressure repartition make us think that drops will appear.
-
After 3 s, we still have no interesting results
|