Nonlinear amplification in hydrodynamic turbulence

Autor:	Pui-Kuen Yeung, Katepalli R. Sreenivasan, Kartik P. Iyer
Rok vydání:	2021
Předmět:	Convection Physics Advection Turbulence Mechanical Engineering Reynolds number Mechanics Dissipation Vorticity Condensed Matter Physics Physics::Fluid Dynamics Nonlinear system symbols.namesake Mechanics of Materials Vortex stretching symbols
Zdroj:	Journal of Fluid Mechanics. 930
ISSN:	1469-7645 0022-1120
Popis:	Using direct numerical simulations performed on periodic cubes of various sizes, the largest being $8192^3$ , we examine the nonlinear advection term in the Navier–Stokes equations generating fully developed turbulence. We find significant dissipation even in flow regions where nonlinearity is locally absent. With increasing Reynolds number, the Navier–Stokes dynamics amplifies the nonlinearity in a global sense. This nonlinear amplification with increasing Reynolds number renders the vortex stretching mechanism more intermittent, with the global suppression of nonlinearity, reported previously, restricted to low Reynolds numbers. In regions where vortex stretching is absent, the angle and the ratio between the convective vorticity and solenoidal advection in three-dimensional isotropic turbulence are statistically similar to those in the two-dimensional case, despite the fundamental differences between them.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::69ef07e7e50ea85df8e91e79dc3c2dd8 https://doi.org/10.1017/jfm.2021.914 Zobrazit plný text záznamu