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

How to get the pressure force on a surface?

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   January 16, 2008, 17:21
Default How to get the pressure force on a surface?
  #1
Jimmy
Guest
 
Posts: n/a
Hi guys,

I am trying to calculate the force (including shear and pressure forces) on a surface.

From the Post-Processing manu, we can find the shear force components on X-, Y- and Z- direction, but not that for the pressure force. Who can tell me how to get the pressure force on a surface?

Thanks,

Jimmy
  Reply With Quote

Old   January 16, 2008, 20:30
Default Re: How to get the pressure force on a surface?
  #2
James
Guest
 
Posts: n/a
Look at help for GETW, there are bunch of forces that you can get including FTOT. You will need to activate shear through POWA first to have it on the post file.

You can also use PSYS to get the components in a particular co-ordinate system. For example if you want torque you can get tangential force and distance using the OPER command and make torque.

ACOEFF may be of use depending on what you are trying to do.

Don't forget that STAR creates new shell types when it loads post or boundary data so you need to look at the first GETW/GETB to see their numbers.

If you already have a shell on the surface of interest then

CSET NEWS TYPE XXX VSET NEWS CSET CSET NEWS VSET ALL CSET DELE TYPE XXX (or CSET SUBS TYPE YYY - where YYY are the prostar generated shells)

Will typically give you the new shells on the surface, as with all of these commands you mileage can vary in non standard situations.

  Reply With Quote

Old   January 17, 2008, 09:25
Default Re: How to get the pressure force on a surface?
  #3
Jimmy
Guest
 
Posts: n/a
Hi James,

Thank you for your help. I can get the shear force components, but not the pressure force. Can you tell me how to calculate the pressure force on a shell?

Thanks again.

Jimmy
  Reply With Quote

Old   January 17, 2008, 12:10
Default Re: How to get the pressure force on a surface?
  #4
James
Guest
 
Posts: n/a
Probably GETW FTOT

There are however a huge number of options on pressure reference etc. Reading the help on GETW is necessary to make sure you get what you really want.

Also note forces can be tricky depending on whether the object is truly submerged in the fluid or not. You may need to take into account of pressure forces acting on the object outside the model domain in order to get the true force on the object.
  Reply With Quote

Old   January 17, 2008, 17:37
Default Re: How to get the pressure force on a surface?
  #5
Jimmy
Guest
 
Posts: n/a
Hi James,

I will try GETW FTOT. Thank you for your help.

Jimmy
  Reply With Quote

Old   January 25, 2008, 06:54
Default Re: How to get the pressure force on a surface?
  #6
Anton Lyaskin
Guest
 
Posts: n/a
If you need integral force for the whole region, you can explicitly define it as wall and turn on engineering data for it. You'll get all components of the force in .erd file
  Reply With Quote

Reply


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
how get the force on all a surface iteration ? dupont Main CFD Forum 0 July 25, 2008 06:43
pressure force and viscous force CFD FLUENT 0 March 7, 2006 02:03
Surface Tension Force gopala OpenFOAM Running, Solving & CFD 3 June 14, 2005 08:04
Surface tension - Continuum Surface Force model Robert Main CFD Forum 0 May 2, 2002 08:34
surface tension force Ray Main CFD Forum 0 October 17, 2001 16:42


All times are GMT -4. The time now is 13:16.