CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > FloEFD, FloWorks & FloTHERM

Simulating buoyancy

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

LinkBack Thread Tools Display Modes
Old   June 29, 2008, 10:42
Default Simulating buoyancy
Posts: n/a
I have a question. Can you simulate buoyancy at cosmos floworks 2008? I've got an assembly and i want to put it in water and see if it will float and if it floats than how deep will it sink in the water.

Thanks in advance, Shay
  Reply With Quote

Old   July 2, 2008, 10:30
Default Re: Simulating buoyancy
Vik Vedantham
Posts: n/a
As far as I know, FloWorks does not support Free Surface problems (where the interaction is between a gas and a liquid in the same control volume). In other words, the boundary layer interface between air and water in your assembly cannot be simulated. Thus, capturing the buoyancy and the sunk portion of the assembly might not be feasible.

FloWorks is excellent if the assembly is surrounded by similar fluids (multiple liquids or multiple gases), or even if a liquid and gas are separated into different volumes.

One potential workaround (that is up for debate, though) is modeling Air as a liquid of very low density, or modeling Water as a gas of very high density.

Best Regards,

Vik Vedantham.

  Reply With Quote

Old   July 7, 2008, 11:07
Default Re: Simulating buoyancy
Posts: n/a
I had a question about modelling air as a liquid about the time EFD.Lab ver6 just came out. The problem then (and possibly still is) was that there the solver doesn't like differences in density of more than 10x.

But that doesn't really answer Shay's question. My suggestion is to work out the answer basically on the back of an envelope. Work out how much water must be displaced for the object to float and then manually take cuts through the model to see how far up the water will go.

  Reply With Quote

Old   August 2, 2008, 03:43
Default Re: Simulating buoyancy
Rajesh Thombre
Posts: n/a
Can you simulate buoyancy induced flow through a vertical pipe. The incompressible fluid is intially steady and at rest at some initial temperature Tf. The heat is supplied to the pipe from outside.

Thanking you

  Reply With Quote

Old   September 22, 2008, 16:54
Default Re: Simulating buoyancy
Bill McEachern
Posts: n/a
Come on guys - this is a very basic hydro statics problem and is simple to do with any 3D solid CAD tool if not a bit tedious - just line up the CofG withthe centre of bouyancy of hte displaced liquid and make sure the displaced volume of liquid has the same wt. as the object. Simple sink and trim and you do not need a fluid code - that is taking an excavator when a spoon would do.
  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
calculating buoyancy of a floating body raghav777 CFX 0 June 27, 2011 02:57
How to realize Boussinesq approximation (buoyancy) in Fluent-UDF dochanxu FLUENT 0 October 14, 2010 14:42
"Full" buoyancy model in CFX Jade M Main CFD Forum 2 March 18, 2010 13:08
Buoyancy Turbulence Chilli83 CFX 3 April 14, 2009 20:28
Buoyancy production for species concentration George Gerber FLUENT 1 May 25, 2006 16:56

All times are GMT -4. The time now is 03:08.