CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > General Forums > Main CFD Forum

Immersed boundary method

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   June 2, 2007, 04:09
Default Re: Immersed boundary method
  #21
rt
Guest
 
Posts: n/a
but about IB is "old" & "new",

i agree that concept IB is old, there are some about this in old books, if we look at old books on FDM we see somethig like interpolation based IB, e.g. Ritchmeyer's book or Zienkiewicz & Morgan's book (Finite Elements and Approximation)

but is a new research area, maybe closed and re-opened recently

  Reply With Quote

Old   June 2, 2007, 07:02
Default Re: Immersed boundary method
  #22
phil
Guest
 
Posts: n/a
rt : I use IBM in a very specific case, I'm not sure my work can help you. I work with High order Compact schemes combined with FFT for Poisson resolution. My research area is around DNS and LES flow at low Reynolds.

It's very singular, but if you are always interesting by my work, I can give you one paper and if you can read French I can give my PhD.

Sincerely,

  Reply With Quote

Old   June 2, 2007, 07:35
Default Re: Immersed boundary method
  #23
rt
Guest
 
Posts: n/a
u r right, ur research area is not interesting for me,

but as an expert people in IB, could you please give your idea (probably don't rely on num. experience) about my questions.

also u solve poisson with FFT, i don't have experience with FFT but guess that it is cpu intensive, especially DNS enforce using fine grid, is it?

and why FFT? how is computational cost?

is your system stiff and classical iterative methods fail to converge?

are sparse direct solvers better condidate than FFT (consider robustness and cost)?

  Reply With Quote

Old   June 18, 2015, 10:29
Default Roughness in IBM
  #24
New Member
 
Siamak Gharahjeh
Join Date: Aug 2012
Posts: 27
Rep Power: 13
siamakghh2000 is on a distinguished road
Does anyone know if it is possible to include the effect of roughness on the solid walls by employing immersed boundary method?
As far as I know none of the methods mentioned below can do this.

1-Continous forcing method.
2-Discrete forcing method.
3-Ghost cell IBM.
4-Cut cell method.
siamakghh2000 is offline   Reply With Quote

Old   June 18, 2015, 10:54
Default Roughness in IBM
  #25
New Member
 
Siamak Gharahjeh
Join Date: Aug 2012
Posts: 27
Rep Power: 13
siamakghh2000 is on a distinguished road
Does anyone know if it is possible to include the effect of roughness on the solid walls by employing immersed boundary method?
As far as I know none of the methods mentioned below can do this.

1-Continous forcing method.
2-Discrete forcing method.
3-Ghost cell IBM.
4-Cut cell method.
siamakghh2000 is offline   Reply With Quote

Old   June 19, 2015, 08:24
Default
  #26
Senior Member
 
sbaffini's Avatar
 
Paolo Lampitella
Join Date: Mar 2009
Location: Italy
Posts: 2,149
Blog Entries: 29
Rep Power: 39
sbaffini will become famous soon enoughsbaffini will become famous soon enough
Send a message via Skype™ to sbaffini
Roughness effects can only be included in wall function models, independently from the specific approach (IBM, body fitted, etc.). The underlying reasoning is that if you cannot resolve the wall details
you cannot resolve the wall at all.

As a consequence, if your IBM can handle wall functions (not all of them can) it can also handle wall roughness (if you know how to include it in the wall function model).

However, the Ghost cell method is actually one of several different approaches for the discrete forcing method.
sbaffini is offline   Reply With Quote

Old   June 19, 2015, 11:35
Default
  #27
New Member
 
Siamak Gharahjeh
Join Date: Aug 2012
Posts: 27
Rep Power: 13
siamakghh2000 is on a distinguished road
Thanks. I imagine IBM is more suitable to apply to low Reynolds flows where roughness effect is insignificant.
siamakghh2000 is offline   Reply With Quote

Old   June 19, 2015, 18:30
Default
  #28
Senior Member
 
sbaffini's Avatar
 
Paolo Lampitella
Join Date: Mar 2009
Location: Italy
Posts: 2,149
Blog Entries: 29
Rep Power: 39
sbaffini will become famous soon enoughsbaffini will become famous soon enough
Send a message via Skype™ to sbaffini
Well, there are a number of reasons for which the IBM is more suitable at low Re. However, high Re applications are possible as well. It is important to choose the most suitable IBM flavor for the given application.

For wall roughness you need a method which allows using wall functions. Thus, i would exclude continuous forcing, penalization approaches (with porous like terms) and VOF/level set methods.
sbaffini is offline   Reply With Quote

Old   June 20, 2015, 03:10
Default Solid points coinciding the grids
  #29
New Member
 
Siamak Gharahjeh
Join Date: Aug 2012
Posts: 27
Rep Power: 13
siamakghh2000 is on a distinguished road
Thanks. I think it would be easy to implement wall function if the solid body coincides with the grid points completely. Otherwise, do you know any publication which may have tried a similar attempt?
siamakghh2000 is offline   Reply With Quote

Old   June 20, 2015, 14:06
Default
  #30
Senior Member
 
sbaffini's Avatar
 
Paolo Lampitella
Join Date: Mar 2009
Location: Italy
Posts: 2,149
Blog Entries: 29
Rep Power: 39
sbaffini will become famous soon enoughsbaffini will become famous soon enough
Send a message via Skype™ to sbaffini
Look for the works of Capizzano or De Tullio, i don't remember now the titles (just add IBM to their names).

The group working on the code NASCART-GT has also produced in this field.

However, the idea is trivial. The wall normal velocity gradient computed by the wall function just has to substitute the one entering the the computation of the viscous term at walls.

The specific details obviously depend from the method.
sbaffini is offline   Reply With Quote

Old   June 12, 2017, 14:59
Default hi mr safar ,can i take your mail? i have some quiztion about immersed boundray
  #31
New Member
 
Join Date: Jun 2017
Posts: 2
Rep Power: 0
leilii is on a distinguished road
Quote:
Originally Posted by sfar
;49891
Hi,

I intend to carry my research on Immersed Boundary Method. I have already read lots of articles on IB method. Now what I need actually is a piece of code illustrating implementation of the IB method. Do anyone know any source from where i can get some initial idea about IB coding? I will prefer finite volume discretisation of the governing equations. Thanks in advance.

Sfar
hi mr safar ,can i take your mail? i have some quiztion about immersed boundray
leilii is offline   Reply With Quote

Old   June 21, 2017, 04:52
Default
  #32
New Member
 
Join Date: Jun 2017
Posts: 2
Rep Power: 0
leilii is on a distinguished road
Quote:
Originally Posted by Junseok Kim
;49929
hi
this link doesnt open for me
can you send me thats contain?
i need ibm code
tnnnxx
leilii 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
Wind turbine simulation Saturn CFX 58 July 3, 2020 02:13
implementation of the Immersed Boundary Method mi_cfd Main CFD Forum 19 April 24, 2019 02:24
Code for Immersed Boundary Method (ask for help) syq129 Main CFD Forum 2 November 23, 2010 04:16
Ghost Cell Immersed Boundary mnabi Main CFD Forum 0 November 7, 2009 07:16
Immersed boundary method (IBM) vs Dynamic meshing tomyangbath Main CFD Forum 5 April 17, 2009 04:02


All times are GMT -4. The time now is 02:23.