Amplitude and Frequency Modulation of The Small Scales in A turbulent Jet
Categories: Journal
Author: D. Fiscaletti, G.E. Elsinga, B. Ganapathisubramani, J. Westerweel
Year: 2013
This work involves the large-scale amplitude and fre- quency modulation of the small-scale motions in fully- developed turbulence of a high Reynolds number jet.
The scales responsible for the production of turbulent kinetic en- ergy (large scales), and those responsible for its viscous dis- sipation (small scales) are extracted from time series of hot- wire signals, using a band-pass spectral filter
Strength of the large-scale fluctuations affect non-linearly the amplitude of the small-scale signal.
The estimated Kolmogorov scale is around $60\mu $m (frequency 30kHz using Taylor Hypothesis). This work also encountered the signal noise when the sampling frequency is higher than 22kHz so they used low-pass filter. Then the smallest eddy size can be captured is $90 \mu$m (1.5 Kolmogorov scales).