Wave dispersion in moderate channel turbulence

Chiara Pilloton; Claudio Lugni; Giorgio Graziani; Francesco Fedele

doi:10.1038/s41598-023-32978-7

Wave dispersion in moderate channel turbulence

Sci Rep. 2023 Apr 26;13(1):6801. doi: 10.1038/s41598-023-32978-7.

Authors

Chiara Pilloton¹, Claudio Lugni^{1

2

3}, Giorgio Graziani⁴, Francesco Fedele⁵

Affiliations

¹ CNR-INM, Institute of Marine Engineering, Via di Vallerano 139, 00128, Roma, Italy.
² NTNU-AMOS, Center for Autonomous Marine Operation Systems, Trondheim, Norway.
³ Institute of Marine Hydrodynamics, Harbin Engineering University, Harbin, China.
⁴ Department of Mechanical and Aerospace Engineering, Sapienza Universitá di Roma, Roma, Italy.
⁵ School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, USA. fedele@gatech.edu.

Abstract

We study channel turbulence by interpreting its vorticity as a random sea of ocean wave packet analogues. In particular, we investigate the ocean-like properties of vortical packets applying stochastic methods developed for oceanic fields. Taylor's hypothesis of frozen eddies does not hold when turbulence is not weak, and vortical packets change shape as they are advected by the mean flow, altering their own speed. This is the physical manifestation of a hidden wave dispersion of turbulence. Our analysis at the bulk Reynolds number Re_b = 5600 suggests that turbulent fluctuations behave dispersively as gravity-capillary waves, with capillarity being dominant near the wall region.