Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here


Turbine vibration , phase angle meaning

Turbine vibration , phase angle meaning

Turbine vibration , phase angle meaning

we are measuring vibrations on steam turbine on bearing 1 and bearing 3 . we found that amplitude of bearing 1 is slightly changing but at a same phase angle which is 262 degree . Also the amplitude of bearing 2 is slightly changing but at same phase angle which is 162 degree . I understand that the two waves of two bearings are opposite in phase but my question is what is the phase angle 262 and 162 means in a simple sin wave curve or how it is measured or determined ? and what does is indicats ?

RE: Turbine vibration , phase angle meaning


when you talk about phase you are talking about delay from a reference.
The reference could be a trigger (key phasor for example) or another signal (ex sinevawe) and in second chase normally the delay is from the peak.

Taking the simplest way (kephasor or trigger) the phase is a delay from Peak of your signal respect of impulse of your trigger.

The delay espressed in ms is a time delay but respect to entire period of your sinusoid you can calculate the phase with:


Below a picture can help you to understand

RE: Turbine vibration , phase angle meaning

I can't open the picture can you send it to this mail ahanber@pgesco.com

RE: Turbine vibration , phase angle meaning

Phase angle means relative time gap between the peak amplitude of the measurements (reactions or displacements). In your case the bearing 1 get peak amplitude is approximately 1/3 period earlier than bearing 3 gets its peak reaction

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close