Decaying two-dimensional turbulence is characterized by the emergence of coherent vortices, which’subsequently dominate the evolution. The temporal scaling behavior of the flow is analyzed using a scaling theory, a long-time integration of the fluid equations, and a dissipative, modified point-vortex model that represents the turbulence as a system of interacting coherent structures. Good agree...

A variety of chaotic flows evolving in relatively high-dimensional spaces are considered. It is shown through the use of an optimal choice of basis functions, which are a consequence of the Karhunen-Loeve procedure, that an accurate description can be given in a relatively low-dimensional space. Particular examples of this procedure, which are presented, are the Ginzburg-Landau equation, turbul...

What is the coherence of organisms? The organism is not a heat engine Energy storage in the living system-to equilibrate and not to equilibrate Energy storage over all space-time domains How is energy mobilized in living systems? The thermodynamics of symmetrically coupled flows The thermodynamics of cyclical flows Coupled energy flows are symmetrical and cyclical "Long-range energy continua" C...

Introduction Intracardiac blood flow measurements using 4D Phase Contrast CMR (4D PC-CMR) may contain useful information about cardiac pumping. Lagrangian Coherent Structures (LCS) is a new, operator-independent method which can simplify analysis by partitioning the flow into regions with different origins and destinations. Since LCS are operator-independent, they may be used to define quantita...

Abstract— Large Eddy Simulations (LES) contains 3D instantaneous velocity fields as well as passive scalar concentration field describing the coherent flow structures. The study of coherent flow structures has a major impact on the mixing of the fuel and the oxidizer. The analysis of these structures in a turbulent jet is essential in understanding the fundamentals of fluid dynamics. Therefore ...

Lagrangian coherent structures provide insight into unsteady fluid flow, but their construction has posed many challenges. These structures can be characterized as ridges of a field, but their local definition utilizes an ambiguous eigenvector direction which can point in one of two directions, and its disambiguation can lead to noise and other problems. We overcome these issues with an applica...

One of the ubiquitous features of real-life turbulent flows is the existence and persistence of coherent vortices. Here we show that such coherent vortices can be extracted as clusters of Lagrangian trajectories. We carry out the clustering on a weighted graph, with the weights measuring pairwise distances of fluid trajectories in the extended phase space of positions and time. We then extract ...