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

BoundaryLayer with blowing

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

Reply
 
LinkBack Thread Tools Display Modes
Old   August 7, 2000, 13:39
Default BoundaryLayer with blowing
  #1
Max Nutini
Guest
 
Posts: n/a
How do I better simulate with Fluent a Boundary Layer with blowing or suction? Any hints?

Thanks

Max
  Reply With Quote

Old   August 8, 2000, 11:58
Default Re: BoundaryLayer with blowing
  #2
John C. Chien
Guest
 
Posts: n/a
(1). I think you are talking about the boundary conditions on a wall. (2). When you have fluid going through the wall, there must be a hole or a slot. In this case, the blowing will be an inlet on the wall. And the suction will be an exit on the wall. (3). If you have arrays of holes on the surface, similar to the turbine blade cooling holes, then you need to handle each as an inet. I have done the simulation of 2-D flow over a turbine blade with ten or twelve slots at the wall. Each slot represents an inlet and requires many cells inside to provide the needed resolution. (4). The problem with the holes is that they are 3-D and will take a lot of memory to simulate many holes. Other than that, there is no basic limit to it. (5). The other extreme is the porous plate wall. In this case, what I did on my code was simply set the v-velocity to the desired value, keeping the rest of the wall condition the same. I have not try this type of porous wall using Fluent, so, I don't know whether it is easy to do or not. (6). By the way, porous wall blowing will also change the nature of the turbulent boundary layer flow. So, it is likely that the turbulence model will have to be changed also.
  Reply With Quote

Old   August 9, 2000, 05:21
Default Re: BoundaryLayer with blowing
  #3
Max Nutini
Guest
 
Posts: n/a
Thanks John for your answer. I am glad to have received an answer from you! Yes, I think that that the critical part will be modelling the boundary layer developing on the blowing surface in an appropriate way. Actually, I can obviously not trust in the standard wall functions, I am wondering whether the "2layer" submodel - which as I understand does not model any wall function but solves the flow up to wall surface - can provide reliable results. - Anyway, Trusting is a basic issue in CFD... ;-) - Does anybody have experience at this regard with Fluent? Are UDF appropriate for that? Thanks everybody! Max
  Reply With Quote

Reply

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
CFD of 3D Wing Tip Blowing NLao Main CFD Forum 1 March 1, 2012 02:44
Blowing up in the DNS of boundary layer transition hadesmajesty Main CFD Forum 0 March 28, 2011 08:35
Oscillating cylinder using icoFoam blowing up rieuk OpenFOAM Running, Solving & CFD 5 September 22, 2010 11:25
suction and blowing BC sheila FLUENT 3 September 3, 2007 03:49
Backward Facing Step with Blowing azar Main CFD Forum 1 November 16, 2006 02:01


All times are GMT -4. The time now is 08:53.