Nonexistence of Coherent Structures in Two-dimensional Inviscid Channel Flow

Nonexistence of Coherent Structures in Two-Dimensional Inviscid Channel Flow

Two-dimensional inviscid channel flow of an incompressible fluid is considered. It is shown that if the flow is steady and features no horizontal stagnation, then the flow must necessarily be a parallel shear flow.

On Coherent Structures of Turbulent Open-channel Flow Above a Rough Bed

Present study examines turbulent structures of a rough bed open-channel flow in the context of deterministic approach. Instantaneous velocity field is measured in different hydraulic conditions using two dimensional Particle Image Velocimetry (PIV) in vertical plane and Stereoscopic PIV in horizontal plane. Different techniques and quantities such as swirl strength, two-point and cross-correlat...

GPU-Based Two-Dimensional Flow Simulation Steering using Coherent Structures

We present an exemplary steering system that performs 2D flow simulation and visualization on graphics processing units (GPUs). The topology of a vector field provides the overall structure and therefore lends itself for steering purposes. We build on the concept of Lagrangian coherent structures present as ridges in the finite-time Lyapunov exponent (FTLE). This allows to perform steering with...

Recurrence in 2D inviscid channel flow

Hyperbolic Covariant Coherent Structures in Two Dimensional Flows

A new method to describe hyperbolic patterns in two-dimensional flows is proposed. The method is based on the Covariant Lyapunov Vectors (CLVs), which have the properties of being covariant with the dynamics, and thus, being mapped by the tangent linear operator into another CLVs basis, they are norm independent, invariant under time reversal and cannot be orthonormal. CLVs can thus give more d...