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
Properties of the mean recirculation region in the wakes of two-dimensional bluff bodies
TL;DR: In this article, the authors investigated the properties of the time and span-averaged mean wake recirculation region in separated flows over several different two-dimensional bluff bodies and found that the contribution from Reynolds normal stress to the force balance of the wake bubble is significant.
Journal ArticleDOI
A tutorial on dynamical systems concepts applied to Lagrangian transport in oceanic flows defined as finite time data sets: Theoretical and computational issues
TL;DR: In this paper, the authors show the relationship between fluid transport in two-dimensional time-periodic incompressible flows and the geometrical structures that exist for 2D area-preserving maps, such as hyperbolic periodic orbits, their stable and unstable manifolds and KAM tori.
Journal ArticleDOI
Direct numerical simulations of isotropic compressible turbulence: Influence of compressibility on dynamics and structures
TL;DR: In this article, the statistical properties of compressible isotropic turbulence are analyzed by means of direct numerical simulations and the influence of compressibility on the time evolution of mean turbulence properties is evaluated.
Journal ArticleDOI
The organization of near-wall turbulence: a comparison between boundary layer SPIV data and channel flow DNS data
TL;DR: In this article, the vortical structures of near-wall turbulence at moderate Reynolds number are analyzed and compared in datasets obtained from stereoscopic particle image velocimetry (SPIV) in a turbulent boundary layer and from direct numerical simulations (DNS) in turbulent channel flow.
Journal ArticleDOI
Energy transfer, pressure tensor, and heating of kinetic plasma
Yan Yang,Yan Yang,William H. Matthaeus,Tulasi N. Parashar,Colby Haggerty,Vadim Roytershteyn,William Daughton,Minping Wan,Yipeng Shi,Shiyi Chen,Shiyi Chen +10 more
TL;DR: In this article, scale-dependent spatial filtering on the Vlasov equation is used to extract information at prescribed scales and introduce several energy transfer functions, such as − (P · ∇ ) · u, which can trigger a channel of the energy conversion between fluid flow and random motions.
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.