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Need some help understanding Hertz–Knudsen formula

  1. Feb 12, 2012 #1
    I'm Working on understanding the growth of snow crystals and came across this as a way to calculate the velocity of growth normal to the plane of the crystal facet.
    vn. = α csat csolid r kT. 2πm σsurf. and called it the Hertz–Knudsen formula which I looked up as F = P / (2∏mkT)^1/2

    Terms are from http://authors.library.caltech.edu/456/1/LIBrpp05.pdf

    how are these equal to each other?

    and is this:
    Velocity of Growth= α((csat/csolid*kT/2πm) *(σsurf)) = α(Vkin *σsurf) the correct Excel expression. Thanks for your help everyone.
    Last edited: Feb 12, 2012
  2. jcsd
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