MEASUREMENT UNCERTAINTY FACTORS OF ACOUSTIC FLOWMETERS
Abstract
This paper addresses uncertainty factors associated with the acoustic flowmeter developed in KRISS. Repeated experimental attempts have been made to investigate their effects on the measurement accuracy of the flowmeter and its robustness in various experimental conditions. The attempts have enabled us to sort out the two major uncertainty factors of the acoustic flowmeter; the measurement errors of the acoustic pressure in the pipe and the acoustic wave reflection characteristics (the ratio of the incident wave to reflected one). Their effects are in details discussed. These findings are shown to lead to a new method that can present more accuracy and robustness in measuring the flow velocity in the pipe. The proposed method decomposes the measured acoustic pressure into the incident and reflected wave components and then estimates the flow velocity by choosing one or both of the decomposed wave components. Their choice depends on the acoustic wave reflection characteristics inside the pipe. Since the Mach number is estimated by using the least squares method, it is found to be the best-fitted result. In order to make those points clear, experimental results will be demonstrated in this paper, including the simulation results that were not possible to implement experimentally.
Event details
- Event
- FLOMEKO 2000
- Technical Committee
- TC9
- Place
- Salvador, Bahia, BRAZIL
- Time
- 4 June 2000 - 8 June 2000