title: Ability of a low-dimensional model to predict geometry-dependent dynamics of large-scale coherent structures in turbulence.
abstract: We test the ability of a general low-dimensional model for turbulence to predict geometry-dependent dynamics of large-scale coherent structures, such as convection rolls. The model consists of stochastic ordinary differential equations, which are derived as a function of boundary geometry from the Navier-Stokes equations [Brown and Ahlers, Phys. Fluids 20, 075101 (2008); Phys. Fluids 20, 105105 (2008)]. We test the model using Rayleigh-Bénard convection experiments in a cubic container. The model predicts a mode in which the alignment of a convection roll stochastically crosses a potential barrier to switch between diagonals. We observe this mode with a measured switching rate within 30% of the prediction.
authors.affiliation: Department of Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut 06511, USA.
authors.forename: Kunlun
authors.initials: K
authors.lastname: Bai
authors.affiliation: Department of Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut 06511, USA.
authors.forename: Dandan
authors.initials: D
authors.lastname: Ji
authors.affiliation: Department of Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut 06511, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Brown