Universal Velocity Statistics in Decaying Turbulence

Intermittency Scaling for Mixing and Dissipation in Rotating Stratified Turbulence at the Edge of Instability

“…Finally, a link between inertial and dissipative ranges is consistent with a linear stochastic model for the fast small scales which is successful in giving K(S) ∼ S 2 for climate data [38,39]. In decaying experiments at both low and high R λ using sulfur hexafluoride, the inertial range does not follow a strict power-law, but rather may display a logarithmic correction that is independent of Reynolds number and that may arise from the dissipative range, putting into question their independence [148]. Nonlinearities do not seem to be central to the establishment of non-Gaussian statistics beyond their (necessary) mode-coupling role [149], and it is rather the susceptibility of the system being close to criticality, linking all scales through dissipation that is central to turbulence dynamics and intermittency.…”

Turbulente Strömungen – weiterhin rätselhaft

“…Um nun zu zeigen, dass die Reynolds‐Zahlen tatsächlich hoch genug sind, um die universellen Eigenschaften der Turbulenz testen zu können, haben wir Messreihen bei verschiedenen Reynolds‐Zahlen aufgenommen [4]. Dabei haben wir festgestellt, dass sich die statistischen Größen ab einer bestimmten Reynolds‐Zahl nicht mehr verändern: Die Messungen zeigen die erwartete Universalität.…”

Physics news on the Internet: September 2023 (based on electronic preprints)

“…Turbulence originates on the largest scales, then the energy is transferred to medium scales, and finally dissipates on small scales due to viscosity. C Kuchler, G P Bewley, and E Bodenschatz have performed at the Max Planck Institute for Dynamics and Self-Organization (Germany) a new large-scale experiment to study turbulence in the air [9]. In a tunnel with a volume of 88 m 3 , turbulence with different initial scale distributions was excited using individual controlled blades, and Re was varied over a wide range by changing the air pressure.…”