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"Inertia Dominated"

  1. Sep 1, 2015 #1

    K41

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    So if we have ratios like Reynolds number or Weber number, i,e ratio of inertial to viscous forces and ratio of inertial to surface tension forces respectively, I've seen many texts say that when these non-dimensional numbers are very high, the physics is "inertia dominated".

    I don't really understand what this means. Can anyone explain?

    As an example, for Reynolds number, we say in high Re flows, inertia dominates at the large scales and in high velocity collisions, inertia dominates the surface tension, but what, physically, does that mean?

    Thanks
     
  2. jcsd
  3. Sep 1, 2015 #2

    mfb

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    2016 Award

    Staff: Mentor

    The kinetic energy is so large that surface tension or other effects are negligible.
     
  4. Sep 1, 2015 #3

    K41

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    I agree, I guess my concerns are that historically we've used "inertia dominated" to describe this when in my mind it is kinetic energy, and using the word "inertia" implies something else :s
     
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