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

Resultant force magnitude and direction in CFX-post

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 8, 2009, 09:47
Default Resultant force magnitude and direction in CFX-post
  #1
New Member
 
Join Date: Apr 2009
Posts: 1
Rep Power: 0
sohailgermany is on a distinguished road
Dear friends,
I have a cylindrical surface pressure distribution. I would like to find out the resultant force magnitude and direction due to the pressure on that surface. How to do it in CFX-Post?. What is the difference between the following two approaches:

1. Function: AreaInt (Variable: Pressure) at the selected location in a certain direction
2. Function: Areaavg(Variable: Force) at the selected location

I think, they both should give same answer, but they are not. Perhaps, I am not understanding it right. It would be great help, if someone explain the difference between them.
Thank you.
sohailgermany is offline   Reply With Quote

Old   April 8, 2009, 21:31
Default
  #2
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,863
Rep Power: 144
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
Hi,

The area integral of pressure does not include wall shear. The best way to get the total force on a surface is using the force_x()@Surface command.

Glenn Horrocks
ghorrocks is offline   Reply With Quote

Old   March 19, 2013, 04:52
Default Regading the same problem as discuss above.
  #3
New Member
 
Abhishek
Join Date: Nov 2011
Posts: 6
Rep Power: 15
abhishekchitvar is on a distinguished road
Hello All,
Greetings!

@Mr. Glenn Horrocks ; How to find the location of the resultant force using the geometry and pressure distribution?
abhishekchitvar is offline   Reply With Quote

Old   March 19, 2013, 05:29
Default
  #4
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,863
Rep Power: 144
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
You can calculate it from the force_x() and torque commands. I will leave the derivation of the equations up to you - here's a hint.... torque = force x distance.
ghorrocks is offline   Reply With Quote

Old   March 19, 2013, 08:11
Default
  #5
New Member
 
Abhishek
Join Date: Nov 2011
Posts: 6
Rep Power: 15
abhishekchitvar is on a distinguished road
Hello Mr.Glenn Horrocks,

Thanks for quick reply and suggestion.

However, It's not solve our purpose. We have annular cavity with some thickness, we find out the pressure distribution over inner and outer surface.
also calculate the forces in YZ plane and length in X-direction. Using this we have calculate resutant force and angle. But we could not have idea to find the location i.e x distance, in X-direction i.e axially.

As your suggested that calculate torque and then using this it would be possible to calculate the distance. However, the CFX gives the torque in y and z direction too. but we don't have constraint to our geometry.

If you have more views on the same, Let me know.

Thanking you!

Last edited by abhishekchitvar; April 8, 2013 at 02:05.
abhishekchitvar is offline   Reply With Quote

Old   March 19, 2013, 09:52
Default
  #6
Senior Member
 
Edmund Singer P.E.
Join Date: Aug 2010
Location: Minneapolis, MN
Posts: 511
Rep Power: 21
singer1812 is on a distinguished road
Resultant force location is not unique. It is a vector. Fix one of your points (perhaps on your body) and the other points will fall out.
singer1812 is offline   Reply With Quote

Old   October 27, 2018, 10:32
Default
  #7
New Member
 
Data
Join Date: Oct 2018
Posts: 1
Rep Power: 0
Maneken is on a distinguished road
Quote:
Originally Posted by singer1812 View Post
Resultant force location is not unique. It is a vector. Fix one of your points (perhaps on your body) and the other points will fall out.
Dear Edmung, How to see the location of this vector of total force in x/y direction, when you use function calculator? I need to determine the torque about the pivot of a plate due to pressure of fluid, for that purpose I thought I need a distances of forces acting on it. Thanks in advance
Maneken 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



All times are GMT -4. The time now is 00:33.