Extension of sonic anemometry to high subsonic mach number flows. (2nd February 2017)

• Record Type: Journal Article
• Authors: Otero, R; Lowe, K T; Ng, W F
• Is Part Of: Measurement science & technology. Volume 28:Number 3(2017:Mar.)
• Publication Date: 2017-02-02
• Subjects: sonic anemometry -- compressible flows -- acoustic velocity measurement -- non-intrusive flow measurement -- time of flight techniques -- modified sonic anemometry; Physical measurements -- Periodicals; Scientific apparatus and instruments -- Periodicals; Equipment and Supplies -- Periodicals; Science -- instrumentation -- Periodicals; Technology -- instrumentation -- Periodicals; Mesures physiques -- Périodiques; Physical measurements; Scientific apparatus and instruments; Periodicals; 502.87
• DOI: 10.1088/1361-6501/aa54ed
• Languages: English
• ISSNs: 0957-0233

Abstract

Abstract: In the literature, the application of sonic anemometry has been limited to low subsonic Mach number, near-incompressible flow conditions. To the best of the authors' knowledge, this paper represents the first time a sonic anemometry approach has been used to characterize flow velocity beyond Mach 0.3. Using a high speed jet, flow velocity was measured using a modified sonic anemometry technique in flow conditions up to Mach 0.83. A numerical study was conducted to identify the effects of microphone placement on the accuracy of the measured velocity. Based on estimated error strictly due to uncertainty in time-of-acoustic flight, a random error of ± 4 m s −1 was identified for the configuration used in this experiment. Comparison with measurements from a Pitot probe indicated a velocity RMS error of ± 9 m s −1 . The discrepancy in error is attributed to a systematic error which may be calibrated out in future work. Overall, the experimental results from this preliminary study support the use of acoustics for high subsonic flow characterization.