TY - GEN
T1 - Wavelet analysis of unsteady shock-wave motion on two-dimensional airfoil with vortex generators
AU - Kouchi, Toshinori
AU - Yamaguchi, Shingo
AU - Yanase, Shinichiro
AU - Koike, Shunsuke
AU - Nakajima, Tsutomu
AU - Sato, Mamoru
AU - Kanda, Hiroshi
N1 - Funding Information:
This work was supported by JSPS KAKENHI Grant-in-Aid for Scientific Research (B) 15H04199. The authors appriciate for supporting the wind tunnel operation by JAXA Aerodynamics Research Unit supported.
Publisher Copyright:
© 2016, American Institute of Aeronautics and Astronautics Inc, AIAA, All rights reserved.
PY - 2016
Y1 - 2016
N2 - We visualized the shock wave-boundary layer interaction on a two-dimensional transonic airfoil with and without vortex generators (VGs) by using a fast-framing focusing schlieren imaging. Image processing extracted a time-space trajectory of the shock wave motion from a time-series of the schlieren images. The shock trajectories were analyzed by using the Morlet wavelet. The shock motions in the cases without VGs were quite periodic. The Fourier analysis well extracted the characteristics of the shock motion such as frequency etc. However, the shock motions in the cases with VGs were not periodic. Therefore, the Fourier analysis is not applicable for this case. The wavelet analysis with the statistical significance test gave quantitative measure of change in the shock oscillation around the buffet frequency due to installation of VGs, such as amplitude and intermittency. The wavelet spectrograms revealed that the installation of VGs did not prevent from generating the buffet but just reduced the amplitude of the buffet oscillation.
AB - We visualized the shock wave-boundary layer interaction on a two-dimensional transonic airfoil with and without vortex generators (VGs) by using a fast-framing focusing schlieren imaging. Image processing extracted a time-space trajectory of the shock wave motion from a time-series of the schlieren images. The shock trajectories were analyzed by using the Morlet wavelet. The shock motions in the cases without VGs were quite periodic. The Fourier analysis well extracted the characteristics of the shock motion such as frequency etc. However, the shock motions in the cases with VGs were not periodic. Therefore, the Fourier analysis is not applicable for this case. The wavelet analysis with the statistical significance test gave quantitative measure of change in the shock oscillation around the buffet frequency due to installation of VGs, such as amplitude and intermittency. The wavelet spectrograms revealed that the installation of VGs did not prevent from generating the buffet but just reduced the amplitude of the buffet oscillation.
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U2 - 10.2514/6.2016-1766
DO - 10.2514/6.2016-1766
M3 - Conference contribution
AN - SCOPUS:85007597273
SN - 9781624103933
T3 - 54th AIAA Aerospace Sciences Meeting
BT - 54th AIAA Aerospace Sciences Meeting
PB - American Institute of Aeronautics and Astronautics Inc, AIAA
T2 - 54th AIAA Aerospace Sciences Meeting, 2016
Y2 - 4 January 2016 through 8 January 2016
ER -