A thin-plate orifice has been installed to measure water flow in
a pipe with an inner diameter ( D1) of 0.147m and an orifice
diameter ( D2) of 0.0735m. The orifice pressure taps are located a
distance D1 upstream and D 1/2 downstream of the orifice. Write
a MATLAB ® script to calculate the flow rate, Q, if the measured
pressure drop ( PA PB) is 9000Pa when the water temperature
is 20C. Use the procedure outline by White (2008) as shown.
1. Guess a value for C 0.61.
2. Calculate flow Q ( m3/s ) using the value of C .
3. Calculate velocity in pipe, uA, and the Reynolds number, NRe.
4. Calculate a new value for C using the empirical equation
for the orifice coefficient for D and D /2 taps:
5. Repeat steps (2) through (4) until you converge to constant Q