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

Body to rotate by action of the air flow

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

Reply
 
LinkBack Thread Tools Display Modes
Old   June 16, 2010, 08:39
Default Body to rotate by action of the air flow
  #1
New Member
 
Roberto Pravata
Join Date: Jun 2010
Posts: 3
Rep Power: 7
rpravata is on a distinguished road
Hi all, I need your help

How can I do for a body to rotate by action of the air flow?

I want to know the speed of rotation as a function of air velocity.

Do I have to do with "moving reference frame model? or "rigid body motion model?

Many thanks.
rpravata is offline   Reply With Quote

Old   June 16, 2010, 11:29
Default
  #2
f-w
Senior Member
 
Join Date: Apr 2009
Posts: 129
Rep Power: 8
f-w is on a distinguished road
What you need to use to accomplish your goal is the "6-DOF Motion Model." You can then setup reports to monitor rotation rate.

Since this is a complicated model, I suggest you read all the help documentation and practice on very simple geometry first.
f-w is offline   Reply With Quote

Old   June 27, 2010, 14:31
Default
  #3
New Member
 
Roberto Pravata
Join Date: Jun 2010
Posts: 3
Rep Power: 7
rpravata is on a distinguished road
THANKS!!!

but one more question
how do I put up resistance to rotation.

thank you very much
rpravata is offline   Reply With Quote

Old   June 28, 2010, 11:38
Default
  #4
f-w
Senior Member
 
Join Date: Apr 2009
Posts: 129
Rep Power: 8
f-w is on a distinguished road
HELP > Modeling > Modeling Dynamic Fluid Body Interaction > Working with 6-DOF Bodies > What are External Forces and Moments? > Adding an External Force or Moment

Read the help file, there's a damping moment, and a damping force you can add.
f-w is offline   Reply With Quote

Old   June 29, 2010, 10:19
Default
  #5
New Member
 
Roberto Pravata
Join Date: Jun 2010
Posts: 3
Rep Power: 7
rpravata is on a distinguished road
Yes, thank very much.

You are the Best.

From Spain realy thanks.
rpravata is offline   Reply With Quote

Old   August 9, 2010, 16:31
Default
  #6
New Member
 
Rafael Oliveira
Join Date: Mar 2010
Posts: 6
Rep Power: 7
rafasdo is on a distinguished road
Hi rpravata,

Do you had success in simulation? Here, I have a channel (2D) with a square in the middle and I'd like to simulate the rotate this object by action of the fluid flow. I've been using a 6DOF udf together with dynamic mesh, but when I run the solver after some iterations appear the following error: Warning: negative volume detected --> repeat smoothing!
I've tried decrease the time step, but the error persists. Following below the udf that I've been using:

include "udf.h"

DEFINE_SDOF_PROPERTIES(quadrado, prop, dt, time, dtime)

{
prop[SDOF_ZERO_TRANS_X] = TRUE;
prop[SDOF_ZERO_TRANS_Y] = TRUE;
prop[SDOF_ZERO_TRANS_Z] = TRUE;
prop[SDOF_ZERO_ROT_X] = TRUE;
prop[SDOF_ZERO_ROT_Y] = TRUE;

/* Define the mass matrix */

prop[SDOF_MASS] = 1;
prop[SDOF_IXX] = 0.25;
prop[SDOF_IYY] = 0.25;
prop[SDOF_IZZ] = 0.50;

printf ("\n2d_test_box: Updated 6DOF properties");
}


Quote:
Originally Posted by rpravata View Post
Hi all, I need your help

How can I do for a body to rotate by action of the air flow?

I want to know the speed of rotation as a function of air velocity.

Do I have to do with "moving reference frame model? or "rigid body motion model?

Many thanks.
rafasdo 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
How to give B.C for tranisent air flow Vijayaragavan FLUENT 0 January 25, 2008 13:29
How to give transient air flow Vijayaragavan FLUENT 0 January 23, 2008 23:46
External Flow Around A Body S. FLUENT 7 June 10, 2007 04:05
Modelling air flow around a sphere Fergie FLUENT 1 December 5, 2005 16:27
Hot rod in transverse air flow Anders Larsson Main CFD Forum 3 April 19, 1999 09:28


All times are GMT -4. The time now is 22:56.