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

Simulation of thermocline in a tank

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

Like Tree1Likes

Reply
 
LinkBack Thread Tools Display Modes
Old   January 12, 2014, 07:18
Default
  #21
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 10,830
Rep Power: 85
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
If your flow is near turbulence transition it is going to be very tricky. Normal turbulence models do not work well in this region (but some work better than others - SST is far better than normal k-e for instance).

You are probably going to need a transient LES style simulation, and a laminar flow model may well be as good as anything. For example my PhD thesis looked at exactly this sort of thing in a piston/cylinder arrangement - see http://hdl.handle.net/10453/20133 in chapter 6.
fkhan7 likes this.
ghorrocks is offline   Reply With Quote

Old   May 19, 2014, 12:25
Default Good point
  #22
New Member
 
Fahad Khan
Join Date: Jun 2010
Location: USA
Posts: 8
Rep Power: 7
fkhan7 is on a distinguished road
I am trying to simulate thermocline formation in a tank and so far i have tried K-e and SST model with no luck of matching my experimental results. I will try LES and post my results.

Thank you for your input and sharing your thesis,

Fahad
fkhan7 is offline   Reply With Quote

Old   May 21, 2014, 04:15
Default
  #23
Member
 
Deutschland
Join Date: Nov 2012
Posts: 31
Rep Power: 4
FluidCFD is on a distinguished road
Hi,

I have successfully done my simulation for a 6.5 m tank with a stratification device with diameter 125 mm and a volume flow of 1 m/h. I used laminar flow and the results match the experimental data quite well (see attachment).

The green line is the starting temperature distribution, the yellow line the inflow temperature. The purple curve shows the result of the experiment (after 3 h 7 min). Finally, the red line is my simulation result.

I'm still not sure how to proceed with higher volume flows. If you have new insights concerning this problem, please let me know.

Best regards.
G.
Attached Images
File Type: jpg Stratification 6,5 m.jpg (42.2 KB, 8 views)
FluidCFD is offline   Reply With Quote

Old   May 21, 2014, 09:09
Default Flow parameters
  #24
New Member
 
Fahad Khan
Join Date: Jun 2010
Location: USA
Posts: 8
Rep Power: 7
fkhan7 is on a distinguished road
Hello G,

what is you Re and Fr number and what time of inlet shape are you using?

From what i have seen now, even at Re= 1000 the flow seem to be turbulent.

Regards,

Fahad
fkhan7 is offline   Reply With Quote

Old   May 21, 2014, 09:48
Default
  #25
Member
 
Deutschland
Join Date: Nov 2012
Posts: 31
Rep Power: 4
FluidCFD is on a distinguished road
Hi,

the type of inlet shape can be seen in the attachments of post #7 and #17 in this thread. What dimensions do you use in Re and Fr? Diameter of stratifier or tank or some other dimensions?

Best regards.
G.
FluidCFD is offline   Reply With Quote

Reply

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
simulation of free surface of stirred tank using vof jamalf64 FLUENT 39 April 22, 2013 01:10
Need Help! High pressure Gas discharge from tank to tank through a pipe superarthur86 FLUENT 1 April 2, 2012 14:58
Roll Tank Simulation Sam CFX 14 February 15, 2009 21:21
Pressure BCs for rasInterFoam tank fillingdraining problem kwardle OpenFOAM Running, Solving & CFD 8 September 17, 2008 14:37
simulation of a stirred tank hu CFX 0 February 17, 2001 08:23


All times are GMT -4. The time now is 14:36.