Exact coherent states and the nonlinear dynamics of wall-bounded turbulent flows
Wall-bounded turbulence exhibits patterns that persist in time and space: coherent
structures. These are important for transport processes and form a conceptual framework for …
structures. These are important for transport processes and form a conceptual framework for …
Transition to turbulence in shear flows
B Eckhardt - Physica A: Statistical Mechanics and its Applications, 2018 - Elsevier
Pipe flow and many other shear flows show a transition to turbulence at flow rates for which
the laminar profile is stable against infinitesimal perturbations. In this brief review the recent …
the laminar profile is stable against infinitesimal perturbations. In this brief review the recent …
Subcritical axisymmetric solutions in rotor-stator flow
Rotor-stator cavity flows are known to exhibit unsteady flow structures in the form of circular
and spiral rolls. While the origin of the spirals is well understood, that of the circular rolls is …
and spiral rolls. While the origin of the spirals is well understood, that of the circular rolls is …
Streamwise and doubly-localised periodic orbits in plane Poiseuille flow
S Zammert, B Eckhardt - Journal of fluid mechanics, 2014 - cambridge.org
We study localised exact coherent structures in plane Poiseuille flow that are relative
periodic orbits. They are obtained from extended states in smaller periodically continued …
periodic orbits. They are obtained from extended states in smaller periodically continued …
Instability of the optimal edge trajectory in the Blasius boundary layer
In the context of linear stability analysis, considering unsteady base flows is notoriously
difficult. A generalisation of modal linear stability analysis, allowing for arbitrarily unsteady …
difficult. A generalisation of modal linear stability analysis, allowing for arbitrarily unsteady …
Edge states as mediators of bypass transition in boundary-layer flows
The concept of edge states is investigated in the asymptotic suction boundary layer in
relation to the receptivity process to noisy perturbations and the nucleation of turbulent …
relation to the receptivity process to noisy perturbations and the nucleation of turbulent …
Nonlinear optimals in the asymptotic suction boundary layer: transition thresholds and symmetry breaking
The effect of a constant homogeneous wall suction on the nonlinear transient growth of
localized finite amplitude perturbations in a boundary-layer flow is investigated. Using a …
localized finite amplitude perturbations in a boundary-layer flow is investigated. Using a …
Edge tracking in spatially developing boundary layer flows
Recent progress in understanding subcritical transition to turbulence is based on the
concept of the edge, the manifold separating the basins of attraction of the laminar and the …
concept of the edge, the manifold separating the basins of attraction of the laminar and the …
FPGA realization of spherical chaotic system with application in image transmission
JC Nuñez-Perez, VA Adeyemi… - Mathematical …, 2021 - Wiley Online Library
This paper considers a three‐dimensional nonlinear dynamical system capable of
generating spherical attractors. The main activity is the realization of a spherical chaotic …
generating spherical attractors. The main activity is the realization of a spherical chaotic …
Edge manifold as a Lagrangian coherent structure in a high-dimensional state space
Dissipative dynamical systems characterized by two basins of attraction are found in many
physical systems, notably in hydrodynamics where laminar and turbulent regimes can …
physical systems, notably in hydrodynamics where laminar and turbulent regimes can …