caa a22 4500 467893187 CHVBK 20180406152754.0 cr unu---uuuuu 170328e20061201xx s 000 0 eng 10.1007/s10955-006-9112-0 doi (NATIONALLICENCE)springer-10.1007/s10955-006-9112-0 Clustering Properties in Turbulent Signals [Elektronische Daten] [K. Sreenivasan, A. Bershadskii] We consider the telegraph approximation (TA) of turbulent signals by ignoring their amplitude variability and retaining only their ‘zero'-crossing information. We establish a unique relationship between the spectral exponent of a signal and that of its TA, whenever the signal possesses a Gaussian PDF and a spectral shape in which the high-frequency cut-off is sufficiently sharp. The velocity signals in most turbulent flows away from the wall satisfy these conditions adequately, so that the Kolmogorov spectral exponent of −5/3 for the turbulent velocity spectrum corresponds to a −4/3 spectral exponent for its TA. By introducing a new scaling exponent to characterize the tendency of small-scale fluctuations to cluster, we show that the velocity and passive scalar signals display a finite tendency to cluster even in the limit of Re $$\rightarrow \infty$$ . We advance the notion, on the basis of the properties of the TA, that turbulent processes belong to one of two classes—either the ‘white noise' type or the ‘Markov-Lorentzian' type. Springer Science+Business Media, Inc., 2006 Sreenivasan K. International Center for Theoretical Physics, Strada Costiera 11, I-34100, Trieste, Italy aut Bershadskii A. International Center for Theoretical Physics, Strada Costiera 11, I-34100, Trieste, Italy aut Journal of Statistical Physics Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 125/5-6(2006-12-01), 1141-1153 0022-4715 125:5-6<1141 2006 125 10955 https://doi.org/10.1007/s10955-006-9112-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10955-006-9112-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Sreenivasan K. International Center for Theoretical Physics, Strada Costiera 11, I-34100, Trieste, Italy aut NATIONALLICENCE 700 1- Bershadskii A. International Center for Theoretical Physics, Strada Costiera 11, I-34100, Trieste, Italy aut NATIONALLICENCE 773 0- Journal of Statistical Physics Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 125/5-6(2006-12-01), 1141-1153 0022-4715 125:5-6<1141 2006 125 10955 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer