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Active Member
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Registered: ‎01-18-2013
Accepted Solution

Settings rotating frames of reference

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01-18-2013 03:46 AM

I'have this litle problem which wiki doesn't have a answer ready for me;

I wish to model two rotating frames of reference in a fluid flow. Both have opposit rotating directions to each other, while they are in the same plane.


How can I determine whether the rotation direction is clockwise or counterclockwise?


Thnx in advance,



*Expert Elite*
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Registered: ‎08-30-2012

Re: Settings rotating frames of reference

01-18-2013 09:00 PM in reply to: 0785725

Hi Floris,


When dealing with 3D (and even 2D models that can be viewed from "either side"), it is misleading to think of clockwise and counter clockwise. The rotation speed follows the right-hand rule.


I made the attached image to demonstrate the right hand rule. When your thumb points in the direction of the positive axis or vector, the directions that your fingers curl around the axis show the positive rotation or angle. Therefore, a negative value indicates a rotation or angle in the opposite directions.

John Holtz, PE
Mechanical Engineer
Pittsburgh, PA

Simulation Mechanical user since Dec 1997
Active Member
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Registered: ‎01-18-2013

Re: Settings rotating frames of reference

01-22-2013 10:35 AM in reply to: AstroJohnPE

Wow   AstroJohn PE, that was a very precise answer.

And it worked great :smileyhappy:


Thank You so much :smileyhappy:



Now I only have to buy a faster computer.............:smileyfrustrated: