# Mixing with free surface

 User Name Remember Me Password
 Register Blogs Members List Search Today's Posts Mark Forums Read

 April 8, 2013, 22:37 Mixing with free surface #1 New Member   Amir Eshtiaghi Join Date: Apr 2009 Location: Massachusetts, USA Posts: 9 Rep Power: 10 Hi I have a problem of a mixing tank with free surface which diverges after 15 iterations. My problem is a simple cylindrical tank of 6m in diameter and 18m high. the tank has two inlets and two outlets at elevation of 1m that mixing two water streams and extract water from two different outlets. the water height in the tank is 5m and rest of the tank is air above the water. I used VOF model in cfx. above the tank, there is a hole that keeps the air pressure above the water atmospheric. I set the inlet and outlet mass flow rates in a way that the total mass balance is zero. I solved the problem as steady state and initially used an expression of WaterHt=if(y<6 [m],1,0) as initial value. My simulation runs for 15 iterations and then it diverges. i do not understand what I did wrong. I am new in the two phase simulation and spent a long time studying VOF modeling in CFX. I would be grateful if someone can help me on solving this problem. Regards

 April 11, 2013, 23:17 #2 Senior Member   Erik Join Date: Feb 2011 Location: Earth (Land portion) Posts: 668 Rep Power: 13 How are you defining you inlets and outlets? Does the surface really affect the flow, meaning can you just do single phase?

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post zakifoam OpenFOAM Running, Solving & CFD 10 December 12, 2016 12:44 blubb1612 CFX 8 November 28, 2012 11:16 bioman66 CFX 1 June 30, 2006 06:19 Ryan Main CFD Forum 1 August 7, 2001 16:14 Elliot Schwartz Main CFD Forum 5 August 25, 1998 21:03

All times are GMT -4. The time now is 23:01.

 Contact Us - CFD Online - Privacy Statement - Top