In order to reduce aerodynamic noise, understanding the nature of aerodynamic sound sources is important. Generally, aerodynamic sound is measured by using microphones. However, microphones should be installed far from aerodynamic sound sources, which makes difficult to understand the nature of aerodynamic sound sources. As non-contact measurement methods, optical measurement methods of sound have been proposed. Among those, parallel phase-shifting interferometry (PPSI) can capture time-varying phenomena. Recently, simultaneous visualization of flow and sound using PPSI has been proposed. This method enables to capture the propagation of sound inside a flow. In this paper, as an application of aerodynamic sound visualization using PPSI, results of visualization of sound sources of edge tones are shown. The nozzle-edge distance and the flow rate, which are parameters of changing frequency of an edge tone, were adjusted from 5 mm to 13 mm at intervals of 1 mm and from 15 L/min to 45 L/min at intervals of 5 L/min, respectively. The frame rate of the high-speed camera in PPSI was set to 20,000 frames per second and the size of the visualization area was 77 mm by 56 mm. From the visualized images, the characteristics of spatial spread of edge tones were observed.
|Publication status||Published - 2018|
|Event||47th International Congress and Exposition on Noise Control Engineering: Impact of Noise Control Engineering, INTER-NOISE 2018 - Chicago, United States|
Duration: 2018 Aug 26 → 2018 Aug 29
|Other||47th International Congress and Exposition on Noise Control Engineering: Impact of Noise Control Engineering, INTER-NOISE 2018|
|Period||18/8/26 → 18/8/29|
ASJC Scopus subject areas
- Acoustics and Ultrasonics