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Flow (fully dev)

  1. Oct 16, 2012 #1
    I have attached the problem.

    I did the problem, but i'm not confident about my approach or solution. The "fully developed" part is confusing me a little, but anways here'smy approach:

    For v=0.1 m/s
    Reynold's number=(density)*(velocity)*diameter/viscosity
    =1000*.1*0.02/(10^-3)=2000 <<<< I think this indicates that its laminar?
    If so then:
    L/d=.06*Reynold's
    L=.02*.06*2000=2.4m

    For v=10m/s
    Reynold's=200,000 <<< I think this indicates that its turbulent
    If so then:
    L/d=4.4(Reynold's)^(1/6)
    L=.02*4.4*(200000^(1/6))
    =.673m
     
  2. jcsd
  3. Oct 17, 2012 #2
    Let me guess. You are trying to calculate the nominal entry length for flow in a tube. You
    used the correct equations, and implemented them correctly (assuming you got the units right).

    Fully developed flow means that the velocity distribution is not changing with time.
     
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