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

Flow over rotating sphere

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

Reply
 
LinkBack Thread Tools Display Modes
Old   August 11, 2009, 03:57
Default Flow over rotating sphere
  #1
Member
 
mistry
Join Date: Apr 2009
Location: India
Posts: 69
Rep Power: 7
csmistry is on a distinguished road
Hi all
i want to do analysis of flow over rotating sphere.problem is:

to specify rotating domain in CFX Pre i found when i specify sphere as solid domain it is not giving be rotaion option when i specify fluid domain it only gives me option how to solve problem...

secondly i think SST model is best for the selection any suggestion?

how to specify FSinterface... here

Please guide me.
csmistry is offline   Reply With Quote

Old   August 11, 2009, 08:16
Default
  #2
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 9,358
Rep Power: 74
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
Hi,

Assuming you are modelling flow over a rotating sphere with a known velocity then forget about solids, rotating domains or multiple domains. Just have a single domain with the sphere cut out of it. To impose the sphere rotation give the sphere walls a tangential velocity. I think the easiest way to apply this velocity is using a CEL expression to give velocity on the sphere surface as a function of XYZ location - this is easy providing the sphere location is known and the rotation rate is known.

As for which turbulence model is best - that depends on what you are trying to get out of the model and what Reynolds number and Mach number you are running at. SST is a good general purpose one but there are cases when it is not appropriate.

Glenn Horrocks
ghorrocks is offline   Reply With Quote

Old   August 11, 2009, 09:02
Default Rotating sphere
  #3
Member
 
mistry
Join Date: Apr 2009
Location: India
Posts: 69
Rep Power: 7
csmistry is on a distinguished road
Sir,
Really your quick reply energied me do continuous work on CFD...

may i get any hint how to specify rotational velocity using CEL on sphere surface. my idea is to specify inlet region velocity need to specify.

My inlet velocity is 3 m/s and diameter of sphere is 1,1.5 m ,rotational speed 100rpm,150,200 and want to study pressure,velocity distribution on outer surface.

please Guide me.
csmistry is offline   Reply With Quote

Old   August 11, 2009, 19:07
Default
  #4
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 9,358
Rep Power: 74
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
As I said, it is a pretty basic CEL expression to give the sphere a rotating wall. You should be able to derive the expression yourself once you understand the basics of CEL. Have a look in the tutorial examples for some examples of how to use CEL.

Glenn Horrocks
ghorrocks is offline   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
superSonic Flow around sphere prapanj OpenFOAM Running, Solving & CFD 0 March 17, 2009 02:20
Flow around a sphere and a circular cylinder Francis Main CFD Forum 0 September 29, 2008 05:16
meshing F1 front wing Steve FLUENT 0 April 17, 2003 12:37
secondary flow in radial rotating pipe arash Main CFD Forum 0 January 20, 2002 13:49
Inviscid Drag at subsonic, subcritical Mach # Axel Rohde Main CFD Forum 1 November 19, 2001 12:19


All times are GMT -4. The time now is 13:43.