Suppose the flow system in Probs. 7.60 and 7.61 is fluctuating such that the differential pressure varies over a range of ±12 mmH2O while the inlet pressure fluctuates by ±10 kPa. The temperature measurement is within ±2?C. Calculate the resultant uncertainties in the flow rates expressed as a percent of the calculated values.
Probs. 7.61
The orifice in Prob. 7.60 is used to measure the same airstream and the differential pressure reading is observed as 190 mm with all other readings the same. What is the airflow under these conditions?
Prob. 7.60
An orifice is installed according to ASME specifications in a 5.0-cm-diameter pipe. The diameter of the orifice is 2.5 cm and the pressure taps are one diameter upstream and one-half diameter down-stream. Amano meter is used to measure the orifice pressure differential as 1932 mmH2O and the upstream pressure is measured as 400 kPa gage pressure with the local barometer reading as 750 mmHg. The fluid is air at a temperature of 27?C. Calculate the airflow rate in kg/s.