1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Fluid under centrifugal force (Basic)

  1. Sep 14, 2009 #1

    What happens to the fluid in a cylinder that is spinned around it's central axis? Would it matter if there would be a bit of air?

    Thanks very much,
    Last edited: Sep 14, 2009
  2. jcsd
  3. Sep 14, 2009 #2
    Depending on how fast you rotate the cylinder, the shape of the surface will approach that of a paraboloid of revolution.

  4. Sep 14, 2009 #3

    Thanks for the info, but i think i was a bit unclear, as I was meaning that the cylinder is rolling. Forgot that the direction of it will make a difference.

    Any ideas about that?
  5. Sep 15, 2009 #4
    I don't have the math to back this up, but something's nagging at the back of my head to suggest you're more likely to get a catenary rather than a parabola. I Could be totally wrong on this... Anyone know for sure?
  6. Sep 16, 2009 #5
    Check out "Transport Phenomena" by Bird, Stewart, and Lightfoot.

    If the fluid surface is exposed to atmospheric pressure (14.696 psi) then the shape will be a paraboloid of revolution.

  7. Sep 16, 2009 #6
    Why the need for atmospheric pressure? A fluid spun in a rotationally will form a parabola in a vacuum, why is this necessary for the rolling cylinder?
  8. Sep 17, 2009 #7
    Yes, a fluid under vacuum will produce the same result. I was just stating the conditions used in the Transport Phenomena book for clarity.

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