Naslov
A note on the relationship between turbulent coherent structures and phase correlation

Autori
Kang, Yanfei ; Belušić, Danijel ; Smith-Miles, Kate

Izvornik
Chaos: An Interdisciplinary Journal of Nonlinear Science (1054-1500) 24 (2014), 2; 023114, 20

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Coherent structures ; Turbulence research

Sažetak
Various definitions of coherent structures exist in turbulence research, but a common assumption is that coherent structures have correlated spectral phases. As a result, randomization of phases is believed, generally, to remove coherent structures from the measured data. Here, we reexamine these assumptions using atmospheric turbulence measurements. Small-scale coherent structures are detected in the usual way using the wavelet transform. A considerable percentage of the detected structures are not phase correlated, although some of them are clearly organized in space and time. At larger scales, structures have even higher degree of spatiotemporal coherence but are also associated with weak phase correlation. A series of specific examples are shown to demonstrate this. These results warn about the vague terminology and assumptions around coherent structures, particularly for complex real-world turbulence.

Izvorni jezik
Engleski

Znanstvena područja
Geofizika

POVEZANOST RADA