Mass flow rate using a pitot tube

[Poodge*]

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 I am so lost as to what to do with them.
Please someone help me :(

 

[Valkarie]

The first step is to calculate the pressure difference between the stagnation pressure and the static pressure. To do this, you will need to subtract the atmospheric pressure (759 mmHg) from the stagnation pressure readings for each distance from the center. This will give you the pressure difference at each distance. Next, you will need to calculate the velocity of the air at each location. This can be done using the Bernoulli equation and the pressure difference you just calculated. The equation is v = (2(P1-P2)/ρ)^0.5, where P1 is the stagnation pressure, P2 is the static pressure, and ρ is the density of the air.Once you have the velocities for each location, you can calculate the flow rate by multiplying the velocities by the cross sectional area of the venturi. The cross sectional area of the venturi is (π/4)*(D2^2 - D1^2), where D1 is the smaller diameter of the venturi and D2 is the larger diameter. Finally, you can compare the flow rate calculated with the venturi to the flow rate calculated with the pitot tube.