A self-induced mechanism of large-scale helical structures in compressible turbulent flows
Abstract
A novel self-sustaining mechanism is proposed for large-scale helical structures in compressible turbulent flows. The existence of two channels of subgrid-scale and viscosity terms for large-scale helicity evolution is confirmed for the first time, through selecting a physical definition of the large-scale helicity in compressible turbulence. Under the influence of the fluid element expansion, it is found that the helicity is generated at small scales via the second-channel viscosity, and the inverse cross-scale helicity transfers at inertial scales through the second-channel helicity flux. Together, they form a self-induced mechanism, which provides a physical insight into the long-period characteristic of large-scale helical structures in the evolution of compressible flow systems.
Cite
@article{arxiv.2402.01996,
title = {A self-induced mechanism of large-scale helical structures in compressible turbulent flows},
author = {Zheng Yan and Jianchun Wang and Lifeng Wang and Zhu Lei and Junfeng Wu and Junyi Duan and Fulin Tong and Xinliang Li and Changping Yu},
journal= {arXiv preprint arXiv:2402.01996},
year = {2024}
}