Time-Frequency Analysis of Jet Screech Using Short Time Fourier Treansform and Wigner-Ville Distribution.

DOI Web Site Web Site 9 References

Bibliographic Information

Other Title
  • 短時間ＦＦＴとウィグナー分布によるジェットスクリーチの時間‐周波数解析
  • タンジカン FFT ト ウィグナー ブンプ ニヨル ジェット スクリーチ ノ

Search this article

Abstract

Non-stationary signals must be represented in a time-frequency analysis because such signals vary with time. The purpose of the present study is to analyse a degree of a non-stationary sound such as a jet screech, is a type of shock-associated noise which is induced by the flow. In particular, when the pressure ratio (jet pressure/ambient) is higher than about 3.0 in an underexpanded mode, the non-stationarity of the noise is very strong. In this research, a short time Fourier transform (STFT) and Wigner-Ville distribution (WD) have been used to analyse a jet screech represented in a time-frequency domain. An attractive feature of the STFT is its superior in frequency precision. On the other hand, WD has superior ability in resolution of a time-frequency. However it sufferes a bad influence of cross terms. which yield spurious peak spectra. Finally, it is shown that the optimum application to analyse of a jet screech is possible by using STFT and WD method collaterally.

Journal

References(9)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top