Instantaneous three-dimensional vorticity measurements in vortical flow over a delta wing

The effect of slender body on the rolling characteristics of a double delta wing is found by comparing the numerical simulation results of the double delta wing and wing-body configuration. The coupled computation system solving the Navier-Stokes equations and the rolling motion equation alternatively to obtain the unsteady vortical flow around the two configurations while rolling. The results conclusively showed the upwash effect of the slender body enhanced the energy of strake vortex and merged vortex.The aerodynamic lag of double delta wing is weak, contrarily, the time lag effect of the wing-body configuration is significant. The asymmetry vortices structure nearby the trailing edge are believed to be the main reason for the unsteady time lag effect.

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Supersonic three-dimensional flow around a delta wing with blunted leading edges

Fluid Dynamics ◽

10.1007/bf01019555 ◽

1971 ◽

Vol 2 (4) ◽

pp. 113-117

Author(s):

K. M. Magomedov ◽

A. S. Kholodov

Keyword(s):

Delta Wing ◽

Three Dimensional ◽

Three Dimensional Flow ◽

Dimensional Flow ◽

Leading Edges

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Boundary-Layer Flow Between the Attachment Lines on a Flat Plate Delta Wing at Incidence

Aeronautical Quarterly ◽

10.1017/s0001925900002213 ◽

1962 ◽

Vol 13 (1) ◽

pp. 1-16

Author(s):

J. C. Cooke

Keyword(s):

Boundary Layer ◽

Delta Wing ◽

Three Dimensional ◽

External Flow ◽

Two Dimensional ◽

Conical Flow ◽

Slender Body Theory ◽

Layer Flow ◽

Body Theory ◽

Transition Fronts

SummaryA three-dimensional laminar-boundary-layer calculation is carried out over the area concerned. The external flow is simplified, being calculated by slender-body theory assuming conical flow, with two point vortices above the wing, their positions and strength being determined by experiment. Attempts are made to draw transition fronts both for two-dimensional and sweep instability from this calculation. The combination of these gives fronts similar to those observed in some experiments. Because there is little or no pressure gradient over the area in question it is suggested that it is a region where distributed suction might usefully be applied in order to maintain laminar flow and reduce drag.

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Numerical study of vortical flow over a sideslipping delta wing

10.2514/6.1990-3001 ◽

1990 ◽

Author(s):

C.-H. HSU ◽

C. LIU

Keyword(s):

Delta Wing ◽

Numerical Study ◽

Vortical Flow

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Novel Turbine Endwall Contours for the Reduction of Heat Transfer Generated Using the Ice Formation Method

Volume 7: Fluids and Heat Transfer, Parts A, B, C, and D ◽

10.1115/imece2012-87430 ◽

2012 ◽

Author(s):

Kristian Haase ◽

Sven Winkler ◽

Bernhard Weigand ◽

Sven Olaf Neumann

Keyword(s):

Heat Transfer ◽

Guide Vane ◽

Three Dimensional ◽

Vortical Flow ◽

Ice Formation ◽

The Novel ◽

Average Heat ◽

Low Pressure Turbine ◽

Transfer Behavior ◽

Formation Method

Three-dimensional contouring of vane endwalls has proven to be an efficient method for reducing aerodynamic losses or, respectively, endwall heat transfer by active manipulation of the complex vortical flow structures in the vane passage. The present study shows the application of the Ice Formation Method for endwall contouring of a guide vane row with the goal of reducing endwall heat transfer. Endwall contours for the guide vane row of a low pressure turbine are experimentally generated in form of ice contours and evaluated with respect to their heat transfer behavior. A comparison with the flat plate showed that average heat transfer is considerably reduced for the ice-contoured endwalls with reductions up to 42%. The generated endwall contours were also digitized and used in numerical simulations. The latter allowed for a comparison of endwall heat transfer for the novel contours with the heat transfer for a flat, uncontoured endwall. This showed that the new endwall contours also feature decreased average heat transfer compared to the flat endwall with the maximum obtained reduction being 12%.

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Flow/Acoustic Mechanisms in Three-Dimensional Vortices Undergoing Sinusoidal-Wave Instabilities

Volume 1: Advances in Aerospace Technology ◽

10.1115/imece2007-43163 ◽

2007 ◽

Cited By ~ 1

Author(s):

Wenhua Li ◽

Z. C. Zheng ◽

Ying Xu

Keyword(s):

Flow Field ◽

Three Dimensional ◽

Vortex Pair ◽

Particle Method ◽

Acoustic Signals ◽

Short Wave ◽

Vortical Flow ◽

Vortex Particle Method ◽

Structure Changes ◽

Wave Instabilities

It has been identified that vorticity in a vortex core directly relates to the frequency of a significant sound peak from an aircraft wake vortex pair where each of the vortices is modeled as an elliptic core Kirchhoff vortex. In three-dimensional vortices, sinusoidal instabilities at various length scales result in significant flow structure changes in these vortices, and thus influence their radiated acoustic signals. In this study, a three-dimensional vortex particle method is used to simulate the incompressible vortical flow. The flow field, in the form of vorticity, is employed as the source in the far-field acoustic calculation using a vortex sound formula that enables computation of acoustic signals radiated from an approximated incompressible flow field. Cases of vortex rings and a pair of counter-rotating vortices are studied when they are undergoing both long- and short-wave instabilities. Both inviscid and viscous interactions are considered and effects of turbulence are simulated using sub-grid-scale models.

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