Journal ArticleDOI
A general classification of three-dimensional flow fields
TLDR
In this paper, the geometry of solution trajectories for three first-order coupled linear differential equations can be related and classified using three matrix invariants for elementary three-dimensional flow patterns defined by instantaneous streamlines for flow at and away from no slip boundaries for both compressible and incompressible flow.Abstract:
The geometry of solution trajectories for three first‐order coupled linear differential equations can be related and classified using three matrix invariants. This provides a generalized approach to the classification of elementary three‐dimensional flow patterns defined by instantaneous streamlines for flow at and away from no‐slip boundaries for both compressible and incompressible flow. Although the attention of this paper is on the velocity field and its associated deformation tensor, the results are valid for any smooth three‐dimensional vector field. For example, there may be situations where it is appropriate to work in terms of the vorticity field or pressure gradient field. In any case, it is expected that the results presented here will be of use in the interpretation of complex flow field data.read more
Citations
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Journal ArticleDOI
Coherent structures and the saturation of a nonlinear dynamo
TL;DR: In this article, Eulerian and Lagrangian tools are used to detect coherent structures in the velocity and magnetic fields of a mean-field dynamo, produced by direct numerical simulations of the three-dimensional compressible magnetohydrodynamic equations with an isotropic helical forcing and moderate Reynolds number.
Journal ArticleDOI
Vortex identification from local properties of the vorticity field
TL;DR: In this article, the authors classify the instances where the accuracy of the λci-criterion is affected by nonlinear superposition effects and propose an alternative vortex detection scheme based on the local curvature properties of the vorticity graph (x,y,ω).
Journal ArticleDOI
A method for characterizing cross-sections of vortices in turbulent flows
TL;DR: In this article, a new method for characterizing cross-sections of vortices in turbulent flows is described. But the method is not robust, robust, not selective, and above all, much less contaminated by shear than the existing methods.
Journal ArticleDOI
Droplet-turbulence interactions and quasi-equilibrium dynamics in turbulent emulsions
TL;DR: In this article, a pseudopotential lattice Boltzmann (PP-LB) method is used to simulate emulsions in homogeneous isotropic turbulence, and the authors show that the PP-LB technique is capable of long stable simulations in certain parameter regions.
Journal ArticleDOI
Particle image velocimetry measurements of flow field behind a circular square-edged orifice in a round pipe
TL;DR: In this paper, a planar particle image velocimetry system was used to measure the flow field downstream of a circular square-edged orifice plate in a round pipe.
References
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Book
Nonlinear Oscillations, Dynamical Systems, and Bifurcations of Vector Fields
TL;DR: In this article, the authors introduce differential equations and dynamical systems, including hyperbolic sets, Sympolic Dynamics, and Strange Attractors, and global bifurcations.
A Reflection on Nonlinear Oscillations, Dynamical Systems, and Bifurcations of Vector Fields
J. Guckenheimer,P. J. Holmes +1 more
TL;DR: In this paper, the authors introduce differential equations and dynamical systems, including hyperbolic sets, Sympolic Dynamics, and Strange Attractors, and global bifurcations.
Book
Differential Equations, Dynamical Systems, and Linear Algebra
Morris W. Hirsch,Steve Smale +1 more
TL;DR: In this article, the structure theory of linear operators on finite-dimensional vector spaces has been studied and a self-contained treatment of that subject is given, along with a discussion of the relations between dynamical systems and certain fields outside pure mathematics.
Journal ArticleDOI
Direct simulation of a turbulent boundary layer up to R sub theta = 1410
TL;DR: In this paper, the turbulent boundary layer on a flat plate, with zero pressure gradient, is simulated numerically at four stations between R sub theta = 225 and R sub tta = 1410.