Pattern formation by turbulent cascades

• 成果类型: Article
• 署名作者: de Wit, Xander M.; Fruchart, Michel; Khain, Tali; Toschi, Federico; Vitelli, Vincenzo
• 署名单位: Eindhoven University of Technology; Centre National de la Recherche Scientifique (CNRS); Universite PSL; Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI); University of Chicago; Consiglio Nazionale delle Ricerche (CNR); Istituto per le Applicazioni del Calcolo Mauro Picone (IAC-CNR); University of Chicago
• 刊物名称: Nature
• ISSN/ISSBN: 0028-3737
• DOI: 10.1038/s41586-024-07074-z
• 发表日期: 2024-03-21
• 关键词: inverse energy cascade; size distribution; bottleneck; aggregation; particles; models; scales; phenomenology; invariant; mechanism

摘要

Fully developed turbulence is a universal and scale-invariant chaotic state characterized by an energy cascade from large to small scales at which the cascade is eventually arrested by dissipation 1-6 . Here we show how to harness these seemingly structureless turbulent cascades to generate patterns. Pattern formation entails a process of wavelength selection, which can usually be traced to the linear instability of a homogeneous state 7 . By contrast, the mechanism we propose here is fully nonlinear. It is triggered by the non-dissipative arrest of turbulent cascades: energy piles up at an intermediate scale, which is neither the system size nor the smallest scales at which energy is usually dissipated. Using a combination of theory and large-scale simulations, we show that the tunable wavelength of these cascade-induced patterns can be set by a non-dissipative transport coefficient called odd viscosity, ubiquitous in chiral fluids ranging from bioactive to quantum systems 8-12 . Odd viscosity, which acts as a scale-dependent Coriolis-like force, leads to a two-dimensionalization of the flow at small scales, in contrast with rotating fluids in which a two-dimensionalization occurs at large scales 4 . Apart from odd viscosity fluids, we discuss how cascade-induced patterns can arise in natural systems, including atmospheric flows 13-19 , stellar plasma such as the solar wind 20-22 , or the pulverization and coagulation of objects or droplets in which mass rather than energy cascades 23-25 . Turbulent energy cascades can be arrested by non-dissipative viscosities, resulting in pattern formation at intermediate length scales.