# Measuring flow rate using a pitot tube watch

1. I am majorly stuck, we are doing a report in which we determine the flow rate using a venturi then compare values with the flow rate from a pitot tube.
So basically we have recorded pressure values with a pitot tube, moving the tube 2mm from the centre of the venturi each time and re-recording. I believe these are stagnation pressures and I need to calculate the static pressure to work out the velocity? Which i could then use to work out flow rate
We redid this experiment twice after changing the pressure along the venturi
These are the results obtained from the 30mmH20 reading from the manometer

Distance from center Average pitot pressure
0mm 35.55
2mm 34.85
4mm 34.75
6mm 34.5
8mm 34.1
10mm 33.7
12mm 33.15
14mm 31
16mm 25.55

density = 1.247600752 (kg/m^3)
air pressure = 759 mmHg
temperature = 290K
Large diameter of venturi = 108.10 mm
Small diameter of venturi = 29.00 mm

I have all these values and im so lost as to what to do with them.

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Updated: January 3, 2013
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