I am working in a lab where we make some experiments on turbidity currents,
so I am trying to modelize a turbidity current with Fluent to compare the numerical results with the experimental ones.
I've got some difficulties to obtain a good model which is matching
I'm using fluent 14 with a simple geometry (a flume 0.580x5x0.4m or
0.580x5m in 2d) meshed with Gambit (40 000 cells approximately).
I've put water in the flume.
I tried to introduce a turbidity current by a
velocity inlet in the left side, 0.5 m/s for velocity, 0.1 for volume
fraction of sediment, and 20% for the turbulence intensity.
(I also tried to patch a sediment suspension in the left part of the flume
(density 2500 kg/m3) with a volume fraction of 1 then 0.4, 0.2, 0.1
with water and 20% for turbulence intensity I tried all of them.
Then I've injected water by the left side, I tried different
velocities 10m/s 1m/s 0.5m/s 0.1m/s 0.01 m/s).
I used a pressure based transient model with gravity, and an implicit
Eulerian multiphase model.
For turbulence I used k-epsilon model with RNG, standard wall
functions and dispersed turbulance multiphase model.
Then I've put the granular option in the sediment phase with a
syamlal-obrien interaction with water.
When I solve this problem, I have not got the billows or just the
first one in the head but not in the body.
I posted some movies and pictures here :
What I want to obtain is a model with all the billows of the turbidity current like we can see on this videos for exemple : http://video.google.com/videoplay?do...40257860282305
I tried a lot of different model, parameters, turbulence options ... and I always have an imprecise model (without the billows) so I would like to understand what is wrong with my approach.
|All times are GMT -4. The time now is 09:36.|