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A question about water flow rate

  1. Sep 23, 2010 #1
    Hi all, I'm doing a experiment at home I'm trying to know how the flow rate on the water height that tossed from a nozzle with 3mm of diameter.

    By an other word if there is a relationship between flow and the height please some one explain it to me.

    Also I wana to know if the head pressure if the water height that tossed from a nozzle.

    thanks in advance.
  2. jcsd
  3. Sep 23, 2010 #2


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    Staff: Mentor

    The height the water will go to is a function of the pressure at the exit only. The pressure determines the velocity, which determines the height.
  4. Sep 23, 2010 #3


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    Last edited by a moderator: Apr 25, 2017
  5. Sep 24, 2010 #4
    thanks, russ.

    thank you too nvn, I have read the post but did not reach what I need, I think if I explain the problem a little more you could help so this what the problem.

    I wana the water go for the desired height and want to know how much flow rate and how much head (Q and H) needed so I can choose the right pump.

    And this is the way I imagined the matter:

    I applied this formula "s=s0+(v0*t)+(0.5*a*t^2)" and solved for v0 supposing that:

    s0=0 ............. at the nozzle.
    t=1s ............. I suppose that water reach the desired height in 1s.
    a=9.81 .......... the acceleration due to gravity.

    finding v0 which is the initial velocity the water tossed with from the nozzle.

    Then applying the formula "Flow Rate = 0.25 * pi * (pipe diameter)^2 * velocity"

    solving for flow rate I'll find the needed flow rate so I can select the pump.

    and for the Head Pressure (H) as I know we can determine the needed H approximately by measuring the distance from the spot that the pump stands to the nozzles tossing hole.

    this is the way I calculate things, if it's wrong please help me and by the way I'm a electronic engineering student but like mechanics.

    thanks for you response again.
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