Journal ArticleDOI
A general classification of three-dimensional flow fields
Reads0
Chats0
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
More filters
Journal ArticleDOI
Vortex detection criteria assessment for PIV data in rotorcraft applications
TL;DR: In this article, a simple engineering method for identifying and characterizing vortical structures within a flow field measured with a classic two-component PIV measurement system is proposed, which is robust and reliable, because it is based on the velocity field topology without using velocity derivatives sensitive to the spurious vectors.
Journal Article
Direct numerical simulation of steady state, three dimensional, laminar flow around a wall mounted cube
TL;DR: In this article, the topology and evolution of flow around a surface mounted cubical object in 3D channel flow is examined for low to moderate Reynolds numbers via direct numerical simulations via a home made parallel finite element code.
Journal ArticleDOI
Universality and scaling phenomenology of small-scale turbulence in wall-bounded flows
TL;DR: In this article, the authors investigated the Reynolds number scaling of flow topology in the eigenframe of the strain-rate tensor for wall-bounded flows, which is motivated by earlier works showing that such topologies appear to be qualitatively universal across turbulent flows.
Journal ArticleDOI
A unified definition of a vortex derived from vortical flow and the resulting pressure minimum
TL;DR: In this article, a new definition of a vortex is proposed that integrates the concepts of the invariant swirling motion, the pressure minimum characteristics induced by the swirling motion and the positive Laplacian of the pressure.
Journal ArticleDOI
Consequences of the close relation between Rortex and swirling strength
Václav Kolář,Jakub Šístek +1 more
TL;DR: In this article, it was shown that vortex-identification methods share some relevant properties: (i) both provide the same and, practically, the largest vortex region, (ii) both allow an unlimited uniaxial stretching described by an axisymmetric strain rate, so the strain-rate magnitude inside a vortex may become much larger (without any limitation) than the vorticity magnitude, and (iii) both exhibit a discontinuous outcome, known as the so-called disappearing vortex problem.
References
More filters
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.