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Flow rate to height

  1. Oct 12, 2011 #1
    Urine flow meters are used to diagnose urinary flow obstructions such as might occur in the even of enlargement of the prostate gland in men. The Stream-test™ is a simple home uroflow meter consisting of plastic cup with a hole in the base. The maximum height of the urine in the cup is proportional to the maximum urine flow rate.
    Write an excel spreadsheet to calculate the height of urine within the cup based on the urine flow pattern provided. Plot a graph showing the instantaneous height of the urine versus time and state the maximum urine height achieved. The dimensions of the cup are as follows:
    -The cup is straight sided with an internal diameter of 5cm.
    -The hole in the bottom has a diameter of 0.5cm.
    PLZZZZZZ can sumone just explain how to do the basic cnversions .

    Attached Files:

  2. jcsd
  3. Oct 12, 2011 #2


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    Which basic conversions are you having trouble with?
  4. Oct 13, 2011 #3
    as u can see that in the excel file it shows volumetric flowrates so basically im having trouble with converting flowrates to height .we have been given the whole cup dia and the gole dia too of the cup whose height is to be measured .
  5. Oct 15, 2011 #4
    helpppppp plzzzzzzzzzzzzzzzzzzzzzz
  6. Oct 21, 2011 #5


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    Use Bernoulli's Equation. You can make a few assumptions and end up with this equation:

    [tex] v = \sqrt{2g\Delta{h}} [/tex]

    Multiply that time the area of the hole in the bottom and you end up with the flow rate (which you are given).

    [tex] Q = A\sqrt{2g\Delta{h}} [/tex]

    Solve for h (the height) and plot it.

  7. Oct 24, 2011 #6
    sorry ,i think im just not understanding what ur saying .
    for example if im taking a reading at time =3secs and flow rate = 10 ml/s
    so first step u say is multiply 3 into the smaller area.???even if i do so how come it gives me flowrate ,???can u please elaborate all by some example. i hope u understand that the values r of flow in.i basically need the flow out from which i can get the volume retained n thus the height .
    plz answer ASAP .the deadline is in three daysss;(
  8. Oct 10, 2012 #7
    So I'm a bit unsure if I should start a new thread, but I have a similar problem with similar data. I cannot understand how to apply Bernoulli's equations to the flow rate to solve for height.

    Any help would be appreciated. Examples would be very helpful.

    Thank you
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