CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > CFX

Free Surface Flow with Sediment Transport

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 17, 2008, 11:12
Default Free Surface Flow with Sediment Transport
  #1
M. Riffai
Guest
 
Posts: n/a
Hello CFX Folks,

I am trying to simulate flow over an embankment weir (small trapezoidal dam) where as the bed is mobile. I was successful in simulating the hydrodynamic part, but now I would like to include the effects of the mobile bed. So I believe it is possible to simulate the transport of sediment in three ways:

1- Eulerian-Eulerin Multiphase 2- Lagrangian Particle Transport (although CFX won't let me include two Eulerian-Eulerian models or two continuos phases like air and water with a dispersed phase like solid particles using the Lagrangian model) 3- Create a new material (water and sediment) and an additional variable such as concentration and solve a transport equation (e.g. Poisson or diffusive transport)

I would like some advice on how to define each phase in each of the cases above (if possible. I have a feeling the Lagrangian Particle Transport will not work because the air and water phase cannot both be continuous wtih a dispersed solid phase. I know this has been done before, and I'm sure there is a way around it).

Your help is very much appreciated. Thanks!

Regards, M. Riffai
  Reply With Quote

Old   April 17, 2008, 20:51
Default Re: Free Surface Flow with Sediment Transport
  #2
Glenn Horrocks
Guest
 
Posts: n/a
Hi,

This sounds like it would be best done as a discrete element model. These type of models can account for particle size and packing, settling and motion. At the moment you need to couple to a package like EDEM to do this, but I hear that CFX V12 has some capability in this area. Not sure if it will do what you are looking for.

Regards, Glenn
  Reply With Quote

Old   December 1, 2011, 18:23
Default
  #3
New Member
 
Javier Climent Agustina
Join Date: Nov 2011
Posts: 7
Rep Power: 15
CFD_UJI is on a distinguished road
Hello M. Riffa,

Finally, how did you define this model?
Option 1, 2 or 3? I'm really interested in this system.

I had several problems with option 2 as well, but I think it's the best approach. I wouldn't define solid particles as a "solid dispersed". On the other hand, air and water continuous phases are necesary.

Thanks a lot
CFD_UJI is offline   Reply With Quote

Old   September 5, 2013, 10:45
Default
  #4
New Member
 
marjan
Join Date: Aug 2013
Posts: 11
Rep Power: 13
mdallali is on a distinguished road
HI
I wanna model the pickup rate as expression mentioned by van.Rijn as follow:
P=0.00033(tet-tet_cr/tet_cr)^1.5 * (s-1)^0.6 *g^0.6 *d^0.8/nu^0.2

which ni is diffusivity and s is ratio of densities and d is particle diameter.
How could I nondimensional this expression and relate it to froud-Numbewr and Reynold?

Thanks
mdallali is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Free surface flow over a bump qtian OpenFOAM Running, Solving & CFD 17 August 10, 2010 11:15
Problem with capturing water-spreading for free surface flow devesh.baghel OpenFOAM 2 December 10, 2009 02:21
free surface flow in non-inertial reference frame Tiedingg FLOW-3D 1 February 26, 2009 20:51
Free surface vortex flow Guillaume CFX 3 August 25, 2005 21:52
incompressible free surface flow past cylinder vineet FLUENT 2 April 1, 2002 06:56


All times are GMT -4. The time now is 12:16.