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

How calculate drag force for porous sphere

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 19, 2002, 09:45
Default How calculate drag force for porous sphere
  #1
Chandan Sarkar
Guest
 
Posts: n/a
I want to get drag force at the porous surface . I already got the pressure profile and velocity profile. I define the surface of the porous sphere as interior(B.C.).There is no relation theoritially between drag force and other parameters for porous sphere. If anyone know this kindly help me.

---------Chandan Sarkar
  Reply With Quote

Old   September 20, 2002, 10:07
Default Re: How calculate drag force for porous sphere
  #2
sri
Guest
 
Posts: n/a
Hi Chandan,

Will you be more specific about the simulation you are carrying out.I don't understand

"porous surface" "porous sphere"

regards, sri
  Reply With Quote

Old   September 23, 2002, 03:12
Default Re: How calculate drag force for porous sphere
  #3
Chandan Sarkar
Guest
 
Posts: n/a
Hi Sri,

thanks for your kind reply. Actually I want to get the drag force for a porous sphere. If I define the bc of the porous as wall, then I can easily get the drag force, but for this case fluide not penetrate through the porous sphere. So I forced to define the porous sphere surface as interior and thats why I can't get grag force directly with respect to this interuior b.c. I get the following relation for drag force. You kindly write that how I have to proceed. I already get the pressure profile and vel. profile i.e. I know vel. and pr. at every points.

Calculation of the Drag Force :

A linear momentum balance on a control volume far away from the surface of the sphere yields the force on the body as a function of the change in momentum of the fluid passing through the control volume and the net pressure force on the control volume. For the net force in the ith direction, this momentum balance yields:

Fi = ¦A PdAi - ¦A r vi v.dA ----------(1)

Where, ¦ = sign on integration with respect to the elemental area A. r= density PdAi represent the component of the pressure force acting in the ith direction. The drag force is defined as the force acting opposite to the flow direction.

regards, Chandan

  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
Force can not converge colopolo CFX 13 October 4, 2011 23:03
does anyone know about using comsol 4.0 to calculate drag force sl424 COMSOL 0 November 13, 2010 23:28
Calculate Drag force for flat plate vsun FLUENT 0 October 3, 2010 08:56
How should we calculate the drag force ?? Thinnapong FLUENT 5 May 4, 2008 14:46
meshing F1 front wing Steve FLUENT 0 April 17, 2003 13:37


All times are GMT -4. The time now is 11:47.