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

Free-surface modeling

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   January 12, 2009, 01:08
Default Free-surface modeling
  #1
Sam
Guest
 
Posts: n/a
Hi,

I am currently undertaking a final year thesis which involves the calculation of the wavemaking ressitance of a submarine.

As a result I have to generate a 3D model with a freesurface.

I have done all the tutes in CFX Pre aswell as the tutorials form ANSYS training manuals however I have not really found any particularly helpful for defining the geometry and meshing this kind of problem.

Does anyone know of any tutorials/literature that will aid me in modeling this problem?

I just want to do something basic at first to get the general idea before prgressing.

I was thinking of creating a large rectangle with a small cylinder inside it mkaing them seperate bodies. Then doing a volume mesh in the rectangle and a surface mesh over the cylinder. Then proceeding to set up the boundary conditions simialr to that in tutorial 7 "Free surface flow over a bump"

Is this a valid approach or is it way off? I know the mesh has to be very fine etc. but I just wanted a very simplistic model to start with.

Regards,

Sam
  Reply With Quote

Old   January 17, 2009, 17:13
Default Re: Free-surface modeling
  #2
Chebeba
Guest
 
Posts: n/a
Someone else might disagree, but AFAIAC you'll never be able to do it using CFX meshing. You have way too little control of the boundary layer, the mesher is too fragile and you can't get a good resolution at the free surface without going to structural meshing.

You'll want to run the ICEM Wing Body Tutorial to get the basic meshing knowledge.

It's in something like C:\Program Files\ANSYS Inc\v110\icemcfd\docu\Tutorials\CFD_Tutorial_Files \WingBody (The files)

And then look in the Tutorial Help for instructions.

Imagine that the symmetry plane is the water surface in this case, and extend your model on the other side too.

/C
  Reply With Quote

Reply


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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Which code to go for free surface wave modeling.. Ted Chu Main CFD Forum 7 December 29, 2008 16:42
Hydrofoil modeling near free surface in fluent Mojtaba Lajevardi FLUENT 2 June 7, 2008 05:59
Free Surface Modelling (sloshing) fakir CFX 0 November 23, 2006 03:23
Modeling of free surface in CFD ? Kim TaeMin Main CFD Forum 18 July 16, 2001 12:38
Modeling Free Surface Flows Elliot Schwartz Main CFD Forum 5 August 25, 1998 22:03


All times are GMT -4. The time now is 15:38.