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Homework Help: Buckingham theorem

  1. Jun 1, 2016 #1
    1. The problem statement, all variables and given/known data
    why there is a need to change π3 to π3 ' (which is inverse of reynold number)???? (in 2nd picture)

    2. Relevant equations

    3. The attempt at a solution
    why can we do so ? i was told that π1 = f( π2 , π3 , .......)
    if we use π3' , which is this will change the original meaning of π1 = f( π2 , π3 , .......) , am i right ? IMO, this is wrong , there's no need to change π1 = f( π2 , π3 , .......) 3 to π1 = f( π2 , π3 , .......) 3 ' ...
    can someone explain on it ?

    Attached Files:

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    • 198.PNG
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  2. jcsd
  3. Jun 2, 2016 #2


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    Science Advisor
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    Gold Member

    If π1 is a function of π2 and π3 then it is also true that it is a function of π2 and π3-1. It's just a different function.
    Until you have locked in how f is defined, you are free to choose how to define it.
    That said, I don't see the advantage here in switching from π3 to π3-1.
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