Fanning Friction Factor

  1. Feb 11, 2014 #1

    Maylis

    User Avatar
    Gold Member

    Hello,

    I was wondering if when calculating the fanning friction factor, do english units need to be used?

    The equation for the head friction is

    h_f = 4f(L/D)V^2/2

    where L is the length, D is the diameter of the pipe, and f is the fanning friction factor. This ends up having units of length squared/time squared, but I think it should be power/mass
     
  2. jcsd
  3. Feb 11, 2014 #2

    SteamKing

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    2015 Award

    I don't know about your dimensional analysis. The Fanning friction factor is non-dimensional.

    http://en.wikipedia.org/wiki/Fanning_friction_factor

    BTW, your formula for head loss due to friction is incorrect. It should be:

    h_f = 4f(L/D)V^2/(2g)
     
  4. Feb 11, 2014 #3

    Maylis

    User Avatar
    Gold Member

    Is the g included whether you use english units or not? I get confused when I need to divide by g or not these days since we keep going back and forth with english and SI units
     
  5. Feb 11, 2014 #4

    SteamKing

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    2015 Award

    Yes, the g is always there, even in SI or furlongs per fortnight units. Do a dimensional analysis and confirm.
     
  6. Feb 11, 2014 #5

    Maylis

    User Avatar
    Gold Member

    You can see why I was confused, this is directly and repeatedly on the lecture slides
     

    Attached Files:

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted
Similar Discussions: Fanning Friction Factor
  1. Fatigue Factor (Replies: 1)

Loading...