%0 Journal Article
%T Three-Dimensional Visualization of Shock  Cell Structure and Screech Tone Emission  in Underexpanded Circular Jet
%A Keita Ozawa
%A Takayuki Yamagata
%A Nobuyuki Fujisawa
%J Journal of Flow Control, Measurement & Visualization
%P 1-11
%@ 2329-3330
%D 2022
%I Scientific Research Publishing
%R 10.4236/jfcmv.2022.101001
%X The three-dimensional visualization of flow and screech-tone emission from an underexpanded circular jet is first investigated experimentally using high-speed cross-schlieren imaging and microphone measurements in the cross-sectional planes along the jet axis. This experimental technique allows the visualization of the shock-cell structure, directivity of sound intensity, and frequency spectrum in the cross-sectional planes of the screeching jet. The high-speed cross-schlieren observation of the screeching jet shows the occurrence of an asymmetrical shock-cell structure that is generated by the flapping mode in the screeching jet. This contributes to the generation of a screech tone propagating upstream along the jet axis and non-uniform sound intensities around the jet in circumferential direction. These observations by high-speed cross</span><span style=\"white-space:normal;font-size:10pt;font-family:&quot;\">-</span><span style=\"white-space:normal;font-size:10pt;font-family:&quot;\">schlieren imaging were validated by the microphone measurements.
%K Screech Tone
%K Aeroacoustics
%K Directivity
%K Frequency Spectrum
%K Underexpanded Circular Jet
%K Schlieren Imaging
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=113692