The truncated nozzle shown in the figure below is used to monitor the mass flow rate of methane. The area of the nozzle is 3 cm2 , and the area of the pipe is 12 cm2 . The upstream pressure and temperature from a large tank are 150 kPa(abs) and 30oC, respectively. The back pressure is 100 kPa(abs). [Methane : k = 1.31 , R = 0.518 kJ/kg.K]
a) Calculate the mass flow rate of methane.
b) Calculate the mass flow rate assuming Bernoulli equation is valid, the density being the density of the gas at the nozzle exit.
c) What's the percentage error of the mass flow rate calculated?