Application of the autoregressive method to the spectral analysis of a flow signal

Abstract

Application of the autoregressive (AR) method to the spectral analysis of a turbulent-flow signal is discussed in this paper. When only a small number of samples are available because of the inherent nature of the flow or the limited memory size of the data acquisition device, the autoregressive method is more useful than the fast Fourier transform (FFT) method for spectral analysis, because its resolution is higher than the FFT method for this case. Especially, a low-frequency characteristic is much better analyzed by the autoregressive method. To illustrate the advantage of the AR method, some typical signals often encountered in practical flows are analyzed by the AR method.