Universality in the emergence of oscillatory instabilities in turbulent flows
Pavithran, I., Unni, V., Varghese, A., Sujith, R., Saha, A., Marwan, N. ; https://orcid.org/0000-0003-1437-7039, Kurths, J.
Abstract
Self-organization driven by feedback between subsystems is ubiquitous in turbulent fluid mechanical systems. This self-organization manifests as emergence of oscillatory instabilities and is often studied in different system-specific frameworks. We uncover the existence of a universal scaling behaviour during self-organization in turbulent flows leading to oscillatory instability. Our experiments show that the spectral amplitude of the dominant mode of oscillations scales with the Hurst exponent of a fluctuating state variable following an inverse power law relation. Interestingly, we observe the same power law behaviour with a constant exponent near –2 across various turbulent systems such as aeroacoustic, thermoacoustic and aeroelastic systems.<br>