Sartre's Wagner

Keefe, Terry; Keefe, Simon P.

doi:10.2307/1004264

“…We integrate these cases to t = 2000. From the phenomena observed in Keefe (1996) and others, t = 2000 might not be long enough for a long time transient or long chaotic transient to die out.…”

Section: Interpretation Of Torczynski's Results Using Dynamical Systems Theorymentioning

confidence: 96%

“…In addition to the inherent chaotic and chaotic transient behavior in some physical systems, numerics can independently introduce and suppress chaos as well as chaotic transients. Section 5.1 of Yee & Sweby (1996) shows a practical example of a numerically induced chaotic transient near the onset of turbulence in a direct numerical simulation of a three-dimensional channel flow studied by Keefe (1996). Loosely speaking, a chaotic transient behaves like a chaotic solution (Grebogi et al 1983).…”

Section: Dns Of 2-d Incompressible Flow Over a Backward Facing Stepmentioning

confidence: 99%

On spurious behavior of CFD simulations

Yee

¹

,

Torczynski

²

,

Morton

³

et al. 1999

Int. J. Numer. Meth. Fluids

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Spurious behavior in underresolved grids and/or semi-implicit temporal discretizations for four computational fluid dynamics (CFD) simulations are studied. The numerical simulations consist of (a) a 1-D chemically relaxed nonequilibrium model, (b) the direct numerical simulation (DNS) of 2-D incompressible flow over a backward facing step, (c) a loosely-coupled approach for a 2-D fluid-structure interaction, and (d) a 3-D compressible unsteady flow simulation of vortex breakdown in delta wings. Using knowledge from dynamical systems theory, various types of spurious behaviors that are numerical artifacts were systematically identified. These studies revealed the various possible dangers of misinterpreting numerical simulation of realistic complex flows that are constrained by the available computing power. In large scale computations underresolved grids, semi-implicit procedures, loosely-coupled implicit procedures, and insufficiently long time integration in DNS are most often unavoidable. Consequently, care must be taken in both computation and in interpretation of the numerical data. The results presented confirm the important role that dynamical systems theory can play in the understanding of the nonlinear behavior of numerical algorithms and in aiding the identification of the sources of numerical uncertainties in CFD.

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“…As a result, many companies chose to self-insure their environmental exposures. 8 The companies that did purchase EIL policies often did so because of regulatory or contractual requirements. 9 EIL policies are "claims-made" policies, which are triggered by, or respond to, claims asserted against the policyholder during the policy period or within an additional reporting period after the expiration of the policy rather than by injury or damage during the policy period.…”

Section: Environmental Impairment Liability Policiesmentioning

confidence: 99%

Introduction to environmental risk policies

Gallozzi¹,

Stevens²

2000

Environmental Claims Journal

0

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“…Section 5.1 of Yee & Sweby (1996) shows a practical example of a numerically induced chaotic transient near the onset of turbulence in a direct numerical simulation of a three-dimensional channel flow studied by Keefe (1996). Loosely speaking, a chaotic transient behaves like a chaotic solution (Grebogi et al 1983).…”

Section: Dns Of 2-d Incompressible Flow Over a Backward Facing Stepmentioning

confidence: 99%

On spurious behavior of CFD simulations

Yee

¹

,

Torczynski

²

,

Morton

³

et al. 1997

13th Computational Fluid Dynamics Conference

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Spurious behavior in underresolved grids and/or semi-implicit temporal discretizations for four computational fluid dynamics (CFD) simulations are studied. The numerical simulations consist of (a) a 1-D chemically relaxed nonequilibrium model, (b) the direct numerical simulation (DNS) of 2-D incompressible flow over a backward facing step, (c) a loosely-coupled approach for a 2-D fluid-structure interaction, and (d) a 3-D compressible unsteady flow simulation of vortex breakdown in delta wings. Using knowledge from dynamical systems theory, various types of spurious behaviors that are numerical artifacts were systematically identified. These studies revealed the various possible dangers of misinterpreting numerical simulation of realistic complex flows that are constrained by the available computing power. In large scale computations underresolved grids, semi-implicit procedures, loosely-coupled implicit procedures, and insufficiently long time integration in DNS are most often unavoidable. Consequently, care must be taken in both computation and in interpretation of the numerical data. The results presented confirm the important role that dynamical systems theory can play in the understanding of the nonlinear behavior of numerical algorithms and in aiding the identification of the sources of numerical uncertainties in CFD.

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Sartre's Wagner

Cited by 3 publications

References 0 publications

On spurious behavior of CFD simulations

On spurious behavior of CFD simulations

Introduction to environmental risk policies

On spurious behavior of CFD simulations

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