Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Campbell diagram and is its applicaion

  1. Nov 6, 2011 #1
    Please again a fundamental question.

    Can anyone explain what is a Campbell diagram and its application?

    IS it a plot/comparison between exciting frequencies and natural frequencies mainly illustrating when responance will occur?

    Please help and elaborate above
  2. jcsd
  3. Nov 6, 2011 #2


    User Avatar
    Gold Member

  4. Nov 6, 2011 #3
    Yes, I have and I understand that:

    “Campbell diagram is a plot of the vibration characteristics of the structure compared with the excitation frequencies”

    However, I have been reading the attached extract and was not able to interprate the diagram with respect to it. It (the attached extract) might not require any background. will be grateful if helped.

    Attached Files:

  5. Nov 6, 2011 #4


    User Avatar
    Science Advisor
    Homework Helper

    The diagrams in the wiki link have curves showing how the frequency of the different modes varies with the shaft RPM, and the intersection points where the "rotation speed" line crosses the curves.

    Your diagram doesn't show the curves, it just shows the intersection points with the speed line.

    For a simple rotor (like the Wiki example) you can recognise the shapes of the curves as forwards and reverse whirl modes of the rotor. For a turbine wheel like your example, there isn't usually any obvious "pattern" to the curves and they can intersect each other, so plotting all the curves just makes the diagram look more complicated without adding any useful information.
  6. Jan 28, 2012 #5
    Hi Guys,I have some doubts about how can we find number of engine cylinder with the help of campbell diagram of the intake orifice noise?
    can anyone please help me
  7. Jan 28, 2012 #6
    actullay my question is in the attached file

    Attached Files:

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook