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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Journal ArticleDOI
Reynolds number effects on flow characteristics and aerodynamic performances of a swept-back wing
Shun C. Yen,Lung-C. Huang +1 more
TL;DR: In this article, a NACA 0012 wing model with a sweep-back angle of 38° and an aspect ratio of 10.5 × 10.1 was studied. The surface-flow fields were visualized using the smoke wire and surface oil-flow schemes.
Instationnarités dans une bulle de décollement turbulente : étude expérimentale
TL;DR: In this article, a bi-modale dynamique of the TSB is defined, which is defined as the dynamique d'un ecoulement turbulent massivement decolle ou bulle de decollement turbulente (TSB).
Book ChapterDOI
New Aspects of Vortex Dynamics Relevant to Coherent Structures in Turbulent Flows
Wade Schoppa,Fazle Hussain +1 more
TL;DR: In this paper, the authors survey coherent structure eduction in free and wall-bounded shear flows, their new generic definition of a vortex, incompressible and compressible vortex reconnection, internal core dynamics within vortices, core dynamics-induced mixing layer transition, helical wave decomposition to extract polarized vorticity wavepackets from turbulent flows, and dynamical coupling of coherent structures with fine-scale turbulence.
Journal ArticleDOI
Gap-flow patterns behind twin-cylinders at low Reynolds number
Shun-Chang Yen,Chien Ting Liu +1 more
TL;DR: In this paper, the flow structures, drag coefficients and vortex shedding characteristics around a single square cylinder and twin side-by-side square cylinders were experimentally investigated with various Reynolds numbers (Re) and gap ratios (g*) in a vertical water tunnel.
Journal ArticleDOI
A Direct Numerical Simulation analysis of coherent structures in bubble-laden channel flows
TL;DR: In this paper, a local flow topology analysis of wall-bounded bubble swarms is performed using the invariants of the velocity-gradient tensor, all possible small-scale flow structures can be categorized into two nodal and two focal topologies for incompressible flows.
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.