Journal ArticleDOI
A general classification of three-dimensional flow fields
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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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Dynamics and statistics of heavy particles in turbulent flows
Massimo Cencini,Jérémie Bec,Luca Biferale,Guido Boffetta,Antonio Celani,Alessandra S. Lanotte,Stefano Musacchio,Federico Toschi +7 more
TL;DR: In this paper, direct numerical simulations of turbulent flows seeded with millions of passive inertial particles are presented, where the maximum Reynolds number is Re λ∼ 200 and the acceleration fluctuations as a function of the Stokes number in the range St ∈ [0.16:3].
Journal ArticleDOI
Rortex and comparison with eigenvalue-based vortex identification criteria
Yisheng Gao,Chaoqun Liu +1 more
TL;DR: In this article, an alternative eigenvector-based definition of Rortex is introduced, in which the direction of the possible axis of the local rotation is determined by the real eigen vector of the velocity gradient tensor.
A study of the fine scale motions of incompressible time-developing mixing layers
TL;DR: In this article, Chen et al. examined the geometry and topology of dissipating motions in a variety of shear flows using direct numerical simulations (DNS) and various invariants and related quantities were computed from the velocity gradient tensor.
Journal ArticleDOI
The onset of dynamic stall revisited
Karen Mulleners,Markus Raffel +1 more
TL;DR: In this article, the dynamics and interaction of vortical structures were analyzed within a single dynamic stall life cycle leading to a classification of the unsteady flow development into five successive stages: the attached flow stage, the stall development stage, stall onset, stalled stage, and flow reattachment.
Journal ArticleDOI
Vortices of the Mediterranean Sea: An Altimetric Perspective
TL;DR: In this paper, a common definition of a coherent structure has been used to study the statistical properties of Mediterranean Sea vortices observed by satellite altimeters over a 7-yr period.
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.
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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.