Introduction to Focus Issue: Lagrangian Coherent Structures.

Introduction to Focus Issue: Objective Detection of Coherent Structures.

Validation of blood flow partitioning in 4D phase contrast CMR measurements using lagrangian coherent structures

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...

Extraction of Coherent Structures from Natural and Actuated Flows

We present feature-extraction techniques for numerical and experimental data of complex fluid flows. Focus is placed on efficient analysis and visualization of coherent structures of snapshots, temporal evolution and parameter-dependency of coherent structures. One key enabler are Galilean invariant flow quantities based on pressure, acceleration, vorticity and velocity Jacobians. Other importa...

Visualizing Lagrangian Coherent Structures and Comparison to Vector Field Topology

This paper takes a look at the visualization side of vector field analysis based on Lagrangian coherent structures. The Lagrangian coherent structures are extracted as height ridges of finite-time Lyapunov exponent fields. The resulting visualizations are compared to those from traditional instantaneous vector field topology of steady and unsteady vector fields. The examination is applied to th...

Space-Time Bifurcation Lines for Extraction of 2D Lagrangian Coherent Structures

We present a novel and efficient technique to extract Lagrangian coherent structures in two-dimensional time-dependent vector fields. We show that this can be achieved by employing bifurcation line extraction in the space-time representation of the vector field, and generating space-time bifurcation manifolds therefrom. To show the utility and applicability of our approach, we provide an evalua...