Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 10 of 10 for “"FTLE"”.
-
Identifying dynamical boundaries and phase space transport using Lagrangian coherent structures
… fates. The finite-time Lyapunov exponent (FTLE) method is a general and equation-free method that identifies codimension-one sets which have a locally high rate of stretching around which maximal exponential expansion of line elements occurs. These codimension-one sets thus act as transport …
-
Vortex detection and tracking in massively separated and turbulent flows
… including the finite-time Lyapunov exponent (FTLE), the geodesic LCS, and the Lagrangian-Averaged Vorticity Deviation (LAVD). Each of \h{these} Lagrangian methods \h{is} applied at the centers and boundaries of the vortices to detect the vortex dynamics. </p> <p>The techniques enable the …
-
Atmospheric Lagrangian transport structures and their applications to aerobiology
… notions such as finite-time Lyapunov exponent (FTLE) and the associated Lagrangian coherent structures (LCS) and we attempt to provide mathematical explanations and frameworks for some applied questions which are based on realistic concerns of atmospheric transport phenomena. Accordingly, we …
-
Characterisation of local properties and prediction in chaotic dynamical systems
… distribution of finite-time Lyapunov exponents (FTLE) has multiple maxima. These can be attributed to pieces of the trajectory that stay in the vicinity of islands of different orders. It is shown that in the vicinity of homoclinic tangencies regions of enhanced predictability exist, as measured …
-
Lagrangian Visualization and Real-Time Identification of the Vortex Shedding Time in the Wake of a Circular Cylinder
… to calculate the finite-time Lyapunov exponent (FTLE) field. The locations of Lagrangian saddles, identified as non-parallel intersections of positive and negative time FTLE ridges, are shown to indicate the timing of von Kármán vortex shedding in the wake of a circular cylinder. The Lagrangian …
-
Biodynamic Analysis of Human Torso Stability using Finite Time Lyapunov Exponents
… of the finite time Lyapunov exponent (FTLE) field is evaluated for deterministic and stochastic systems. Two new methods are developed to generate the FTLE field from time series data. Using these methods, Lagrangian coherent structures (LCS) are found for an inverted pendulum, the …
-
The rotor-oscillator flow : searching for coherence amidst chaos
… of chaos. Through finite-time Lyapunov exponent (FTLE) analysis, a roughly optimal coupling was found. The parameters that describe this coupling are the nondimensional oscillation amplitude [epsilon] = 0.125 and frequency [lambda] = 0.4[pi]. In order to understand more about the mixing of …
-
Analysis of the flow structure and reattachment over accelerating non-slender delta-wing planforms
… attack in the OTTER lab by that research group. FTLE analysis of this data, and its comparison with surface pressure and aerodynamic forces, were conducted in the Green Fluid Dynamics Lab in the Syracuse University. Sufficiently strong axial accelerations are shown to enable reattachment at the …
-
Advancing the theory and applications of Lagrangian Coherent Structures methods for oceanic surface flows
… studies with tidally-driven channel flows. The FTLE and spectral clustering analyses were particularly helpful in describing key transient flow features and how they were impacted by tidal forcing and vertical velocities. This could not have been identified from the Eulerian perspective, showing …
-
Data-Driven Variational Multiscale Reduced Order Modeling of Turbulent Flows
… fields (e.g., the finite time Lyapunov exponent (FTLE)), but also Eulerian fields (e.g., the streamfunction). We emphasize that the new Lagrangian ROMs do not employ any closure modeling to model the effect of discarded modes (which is standard procedure for low-dimensional ROMs of complex …