CFD Online Logo CFD Online URL
Home > Forums > FLUENT

Dam break simulation water level decreases over time

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

LinkBack Thread Tools Display Modes
Old   May 9, 2014, 09:32
Default Dam break simulation water level decreases over time
New Member
Join Date: May 2014
Posts: 16
Rep Power: 3
aarratia is on a distinguished road
Hi guys,
After doing the dam break tutorial exercise I was looking at the animation of water level inside the tank. What I see is that the water level decreases overtime. Why is this? After the dam break experiment I tried simulating a settling tank with liquids of different densities. In the settling tank simulation everything looks good my problem is that after 30 seconds (simulation time) the liquid level of the lowest chamber starts to decrease to the point where there is none left. after that the same thing happens to the less dense liquid. I have added a little video for you to see what is happening (in both, the tutorial and in my 2d model. By the way I have used a very similar setup to the dam break tutorial. Maybe it has something to do that the upper walls are set as outlet pressure? If so what other conditions should I use if it is an open to atmosphere settling tank?

dam break tutorial

My simulation

best regards
aarratia is offline   Reply With Quote

Old   May 9, 2014, 10:25
Default backflow created when going from pressure outlet to a wall boundary condition
New Member
Join Date: May 2014
Posts: 16
Rep Power: 3
aarratia is on a distinguished road
I tried changing the boundary conditions at the top of the tank from outlet pressure to wall boundary condition. With these changes my boundary conditions are 1 velocity inlet and 3 pressure outlets. When I do that there is backflow in the material pressure outlets causing air to flow from it. Now there are air pockets at the outlets which is not an expected result. What should I do know?
aarratia 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
Help for the small implementation in turbulence model shipman OpenFOAM Programming & Development 25 March 19, 2014 11:08
Unstabil Simulation with chtMultiRegionFoam mbay101 OpenFOAM Running, Solving & CFD 13 December 28, 2013 14:12
Discrete event simulation vs. fixed time (discrete time simulation) jenjon FLUENT 0 March 10, 2013 07:58
Upgraded from Karmic Koala 9.10 to Lucid Lynx10.04.3 bookie56 OpenFOAM Installation 8 August 13, 2011 04:03
uptodate water distribution network fredius,magige,tanzanian,(e.a) Main CFD Forum 0 January 27, 2002 08:10

All times are GMT -4. The time now is 11:02.