Hostname: page-component-5c6d5d7d68-wp2c8 Total loading time: 0 Render date: 2024-08-22T05:04:57.395Z Has data issue: false hasContentIssue false
  • English
  • Français

Spectral flatness factor and ‘intermittency’ in turbulence and in non-linear noise

Published online by Cambridge University Press:  28 March 2006

D. A. Kennedy  and
S. Corrsin
D. A. Kennedy
Affiliation:
Mechanics Department, The Johns Hopkins University
S. Corrsin
Affiliation:
Mechanics Department, The Johns Hopkins University
Get access Rights & Permissions [Opens in a new window]

Abstract

The flatness factor F of the signal transmitted through a band-pass filter has been measured for the turbulence in a free shear layer and for a squared Gaussian noise. They both show flatness factor increasing with centre frequency fc. In the turbulence, band-passed signals look intermittent and have larger F than the full signal, but in the squared noise, band-passed signals all have smaller F than the full signal although they look more intermittent.

It is shown analytically that the derivative of a smoothed, squared Gaussian noise may have flatness factor either greater or less than the undifferentiated signal.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 10 , Issue 3 , May 1961 , pp. 366 - 370
Copyright
© 1961 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Batchelor, G. K. 1949 The small-scale structure of turbulent motion. Proc. Symp. U.S. Naval Ord. Lab.
Batchelor, G. K. & Townsend, A. A. 1949. The nature of turbulent motion at large wave-numbers. Proc. Roy. Soc. A, 199, 238.Google Scholar
Ikibe, P. 1949 M.Sc. thesis, Johns Hopkins University.
Kac, M. & Siegert, A. J. F. 1947 On the theory of noise in radio receivers with square-law detectors. J. Appl. Phys. 24, 383.Google Scholar
Sandborn, V. A. 1959 Measurements of intermittency of turbulent motion in a boundary layer. J. Fluid Mech. 6, 221.Google Scholar