Feature extraction of separation and attachment lines

Kenwright, David; Henze, Chris; Levit, Creon

doi:10.1109/2945.773805

Cited by 89 publications

(50 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Part (f) shows a closer view of one side. These generally parallel lines of separation and attachment confirm and supplement the observations of "open" separation lines by Kenwright, Henze, and Levit [KHL99].…”

Section: Resultssupporting

confidence: 75%

“…A third visualization challenge arises in many engineering applications because the flow needs to be studied in the close neighborhood of so-called no-slip boundaries: that is, boundaries of solid objects where the flow velocity is constrained to be zero [KHL99]. So another motivation for stream surfaces is to produce a surface near the no-slip boundary such that the flow along this surface provides the needed insights.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Stream Surface Generation for Fluid Flow Solutions on Curvilinear Grids

Gelder

2001

Eurographics

View full text Add to dashboard Cite

Abstract.A stream surface in a steady-state three-dimensional fluid flow vector field is a surface across which there is no flow. Stream surfaces can be useful for visualization because the amount of data presented in one visualization can be confined to a manageable quantity in a physically meaningful way. This paper describes a method for generation of stream surfaces, given a threedimensional vector field defined on a curvilinear grid. The method can be characterized as semi-global; that is, it tries to find a surface that satisfies constraints over a region, expressed as integrals (actually sums, due to discreteness), rather than locally propagating the solution of a differential equation. The solution is formulated as a series of quadratic minimization problems in Ò variables, where Ò is the cross-wind resolution of the grid. An efficient solution method is developed that exploits the fact that the matrix of each quadratic form is tridiagonal and symmetric. Significant numerical issues are addressed, including degeneracies in the tridiagonal matrix and degeneracies in the grid, both of which are typical for the applications envisioned.

show abstract

Section: Resultssupporting

confidence: 75%

Section: Introductionmentioning

confidence: 99%

Stream Surface Generation for Fluid Flow Solutions on Curvilinear Grids

Gelder

2001

Eurographics

View full text Add to dashboard Cite

show abstract

“…The opposite phenomenon is called flow attachment. As pointed out by Kenwright [7], separatrices of the boundary vector field constitute so called closed separation or attachment lines. To quantify flow separation and attachment along a separatrix, we compute the divergent (resp.…”

Section: Boundary Topologymentioning

confidence: 99%

Extraction and Visualization of Swirl and Tumble Motion from Engine Simulation Data

Garth¹,

Laramee²,

Tricoche³

et al. 2007

Mathematics and Visualization

View full text Add to dashboard Cite

Summary. An optimal combustion process within an engine block is central to the performance of many motorized vehicles. Associated with this process are two important patterns of flow: swirl and tumble motion, which optimize the mixing of fluid within each of an engine's cylinders. Good visualizations are necessary to analyze these in-cylinder flows. The simulation data associated with in-cylinder tumble motion within a gas engine, given on an unstructured, time-varying and adaptive resolution CFD grid, demands robust visualization methods that apply to unsteady flow. We present a range of methods including integral, feature-based, and image-based schemes with the goal of extracting and visualizing these two important patterns of motion. We place a strong emphasis on automatic and semi-automatic methods, including topological analysis, that require little or no user input. We make effective use of animation to visualize the time-dependent simulation data and describe the challenges and some of the implementation measures necessary in an application of the presented methods to unstructured, time-varying and volumetric grids.

show abstract

“…However, applying the parallel operator leads again to Equation 1 which corresponds to the 0-isoline of a scalar field in the 2D case. 10 This reformulation permits to obtain continuous lines too. However this definition is quite restrictive because it assumes that separation and attachment lines always have zero curvature.…”

Section: Separation and Attachment Linesmentioning

confidence: 99%

Accurate and Efficient Visualization of Flow Structures in a Delta Wing Simulation

Tricoche

Garth

Bobach

et al. 2004

34th AIAA Fluid Dynamics Conference and Exhibit

View full text Add to dashboard Cite

The paper is concerned with the extraction and visualization of structural features in delta wing dataset resulting from a large-scale Reynolds Averaged Navier-Stokes simulation. Its main contributions are two novel schemes designed for this purpose. First, we introduce a new method for fast and precise extraction of separation and attachment lines on the body of the delta wing. Second, we improve significantly standard stream surface computation schemes to achieve accurate integration even in regions exhibiting complex structures. Additional state-of-the-art flow visualization techniques are used to complete the study of the dataset. The main focus is on the interaction between open separation and attachment lines of the wall shear stress on one hand, and vortices that form in the vicinity of the delta wing on the other hand. These features are key factors in flight stability and their study is mandatory in aircraft design. The paper demonstrates the power of a combined use of line-type feature extraction and stream surface computation to deeply improve understanding of three-dimensional structures and ease the analysis of flow separation and vortex breakdown.

show abstract

Feature extraction of separation and attachment lines

Cited by 89 publications

References 19 publications

Stream Surface Generation for Fluid Flow Solutions on Curvilinear Grids

Stream Surface Generation for Fluid Flow Solutions on Curvilinear Grids

Extraction and Visualization of Swirl and Tumble Motion from Engine Simulation Data

Accurate and Efficient Visualization of Flow Structures in a Delta Wing Simulation

Contact Info

Product

Resources

About