CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > Siemens > STAR-CCM+

Dfbi

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 2, 2010, 02:58
Default Dfbi
  #1
Senior Member
 
Henry Arrigo
Join Date: Jun 2010
Location: Italy
Posts: 100
Rep Power: 15
Henry Arrigo is on a distinguished road
I v a problem with solving a DFBI case. I want too run a boat with thrust force in a domain. is that possible? I mean instead of setting a velocity inlet i want to move the boat using a force acting on it. this case is very helpful to study maneuvering. I v already solved a simple case, but the results are not reliable for example free surface deformation is unreasonable and drag force plot is strange too, but as i expected the whole domain moves in the direction of applied force, and also boat motions seems to be rational. do you have any idea how to come up with this case?
thank you
Henry Arrigo is offline   Reply With Quote

Old   September 12, 2010, 19:57
Default
  #2
Senior Member
 
Join Date: Oct 2009
Location: Germany
Posts: 636
Rep Power: 21
abdul099 is on a distinguished road
If your results are looking strange, there is an error in the set up. Is your domain wide enough? Which boundary conditions do you have? What about the mesh resolution near the surface?
abdul099 is offline   Reply With Quote

Old   September 13, 2010, 07:36
Default
  #3
Senior Member
 
Henry Arrigo
Join Date: Jun 2010
Location: Italy
Posts: 100
Rep Power: 15
Henry Arrigo is on a distinguished road
A domain is created to extend 2*L aft-ward,L forward, and L side-ward from the boat. also L to the top of the domain and 2*L to the bottom. I sett B.Cs as mass flow inlet with rate value equal to zero for inlet and outlet and non-sleep wall for other four faces. and about the mesh resolution, here is the report of volume range: Volume range: [3.9930201368e-009, 9.4388723373e-002] m^3.
Henry Arrigo is offline   Reply With Quote

Old   September 23, 2010, 15:03
Post DFBI maneuvering
  #4
Member
 
Naimish Harpal (MS Aerospace Engr)
Join Date: Jul 2009
Location: Long Beach, CA
Posts: 50
Rep Power: 16
naimishharpal is on a distinguished road
Hi,
First of all, I wanted to know what CFD tool do you use for your DFBI problem? BTW, I am doing the same kind of analysis using NUMECA Fine/Marine. Instead of specifying Inlet BC velocity, I specified various maneuvering style (constant, ramp, sinusoidal, ...etc) to the body centroid. For constant velocities cases, my CFD results were matching with the experimental data.
Anyways, there is a option for external forces under Motion laws, but I havn't tried this option yet. May be you can look into more details at http://www.numeca.com/index.php?id=finemarine.

Thanks.
naimishharpal is offline   Reply With Quote

Old   September 23, 2010, 15:21
Default
  #5
Senior Member
 
Henry Arrigo
Join Date: Jun 2010
Location: Italy
Posts: 100
Rep Power: 15
Henry Arrigo is on a distinguished road
It s obviously STAR-CCM+. Anyway, thank you for your recommendation but I m trying to do this with STAR-CCM+. I know it s feasible. Anyway, Thank you again.
Henry Arrigo is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Info on DFBI for Ship Motion Simone Siemens 17 March 29, 2016 21:19
i need info on DFBI Eleazar Siemens 7 September 2, 2010 03:13
DFBI, turbulence model and ship motion ettax Siemens 1 June 4, 2010 12:31
vof=0.5 in dfbi radiatn STAR-CCM+ 4 April 16, 2009 05:57
DFBI question Atlas Siemens 3 January 21, 2009 16:21


All times are GMT -4. The time now is 23:55.