CFD Online Logo CFD Online URL
Home > Forums > FLUENT

Issues with Mixing

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

LinkBack Thread Tools Display Modes
Old   June 21, 2010, 22:07
Default Issues with Mixing
New Member
John Miller
Join Date: Jun 2010
Location: Sydney
Posts: 1
Rep Power: 0
John_SydUni is on a distinguished road
Hi all, I currently am doing my thesis at the University of Sydney based on the simulation of a saline cavity at the bottom of a river being purged by an overflow of fresh water. My initial testing began using a laminar viscous model which did in fact demonstrate turbulence within the boundaries of the channel and cavity. I was able to simulate this process using the bousinessq approximation with both the saline inside the cavity and the water inside the channel having the same density but different temperatures to initiate the process of diffusion (i.e. purging). The driving forces are highly buoyant in this situation!!

However I have moved on to testing the k-epsilon model which do not seem to give the same results as the laminar solution. I know this is true due to the fact that laminar solution's instability matches those of previous results obtained through numerical solution testing. The k-epsilon models (both standard and RNG) seem to merely create a singular vortex trapped within the cavity which is self perpetuating by the shearing effect of the overflowing fresh water. Therefore there is no ejection of 'saline fluid' (lower temp) above into the channel.

If anyone has any methods on how to properly initiate a turbulent diffusion process between the two fluids in the following problem and or a reason why the k-epsilon models are incapable of achieveing proper purging, please share. It would be most appreciated.
John_SydUni is offline   Reply With Quote


Thread Tools
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 On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
simulate a turbulence mixing flow arya FLUENT 0 August 30, 2007 06:08
Mixing Plane Lee FLUENT 0 August 8, 2003 22:36
ideal gas mixing law and mass-weighted mixing law Shankar FLUENT 0 June 24, 2003 13:25
Mixing time problem Rai FLUENT 1 January 15, 2003 04:43
Mixing plane geometry definition Hbet FLUENT 0 January 18, 2002 08:16

All times are GMT -4. The time now is 14:06.