Surface Reflective Visualizations of Shock-Wave/Vortex Interactions Above a Delta Wing

Donohoe, S. R.; Bannink, W.J.

doi:10.2514/2.12

Cited by 18 publications

(8 citation statements)

References 4 publications

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“…6 and highlighted by the dashed lines. This is also in agreement with the observations of Donohoe and Bannink [5]. Also highlighted are the locations of the other normal shocks described previously.…”

Section: Location Of Shock Waves In Glasgow Solutionsupporting

confidence: 90%

“…The first occurs upstream of the sting tip at approximately x=x cr 0:6, and the second occurs downstream of the sting tip at approximately x=x cr 0:85, where a second shock is found. This second shock is likely to correspond to the rear/terminating shock, as described in the literature [2,5,17] for similar conditions. A third compression region is also found close to the trailing edge, and a third shock is found from the surface pressure contours at this location outboard of the symmetry plane on the wing surface.…”

Section: Location Of Shock Waves In Glasgow Solutionmentioning

confidence: 93%

“…The rear/terminating shock in the 18.5 deg solution is found to be normal to the freestream and wing surface and does not appear to curve downstream outboard of the symmetry plane. This lack of curvature may be due to the influence of the sting, as previous investigations have considered a flat wing without sting support [5].…”

Section: Location Of Shock Waves In Glasgow Solutionmentioning

confidence: 97%

“…From the study of the interaction between longitudinal vortices and normal shocks in supersonic flow [4], it has been found that it is possible for a vortex to pass through a normal shock without being weakened sufficiently to cause breakdown. The flow over slender delta wings is potentially more complex, as the shock is not necessarily normal to the freestream in the vortex core region [5]. Investigation is needed to consider the behavior and onset of vortex breakdown, particularly with respect to shock/vortex interactions.…”

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confidence: 99%

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Shock Effects on Delta Wing Vortex Breakdown

Schiavetta

Boelens

Crippa

et al. 2009

Journal of Aircraft

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It has been observed that delta wings placed in a transonic freestream can experience a sudden movement of the vortex breakdown location as the angle of incidence is increased. The chapter reports on the use Computational Fluid Dynamics (CFD) INTRODUCTIONThe occurrence of shocks on delta wings introduces complex shock/vortex interactions, particularly at moderate to high angles of incidence. These interactions can make a significant difference to the vortex breakdown behaviour. For subsonic flows the motion of the location of onset of breakdown towards the apex is relatively gradual with increasing incidence . The strengthening of the shock which stands off the sting as the incidence is increased can lead to a shock/vortex interaction triggering breakdown. The location of breakdown can shift upstream by as much as 30% of the chord in a single one degree incidence interval [[29-2], ] due to this interaction.From the study of the interaction between longitudinal vortices and normal shocks in supersonic flow it has been found that it is possible for a vortex to pass through a normal shock without being weakened sufficiently to cause breakdown. The flow over slender delta wings is potentially more complex as the shock is not necessarily normal to the freestream in the vortex core region . Investigation is needed to consider the behaviour and onset of vortex breakdown, particularly with respect to shock/vortex interactions.To consider this behaviour, the flow over a sharp leading edged, slender delta wing was considered under subsonic and transonic conditions. This investigation was undertaken as part of the 2nd International Vortex Flow Experiment (VFE-2), a facet of the NATO RTO AVT-113 Task Group, which was set up to consider the flow behaviour both experimentally and computationally over a specified 65° delta wing geometry. The work of VFE-2 built on the first International Vortex Flow Experiment (VFE-1) carried out in the late eighties, which was used to validate the inviscid CFD codes of the time. Progress has been made in both experimental and computational aerodynamics, particularly in turbulence models since the conclusion of the VFE-1. Therefore, it was proposed by Hummel and Redecker that a second experiment should be undertaken to provide a new, comprehensive database of results for various test conditions and flow regimes, to further the understanding of vortical flows. The test conditions considered under the VFE-2 framework include both subsonic and transonic Mach numbers for low, medium and high angles of incidence at a range of Reynolds numbers .

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Section: Location Of Shock Waves In Glasgow Solutionsupporting

confidence: 90%

Section: Location Of Shock Waves In Glasgow Solutionmentioning

confidence: 93%

Section: Location Of Shock Waves In Glasgow Solutionmentioning

confidence: 97%

mentioning

confidence: 99%

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Shock Effects on Delta Wing Vortex Breakdown

Schiavetta

Boelens

Crippa

et al. 2009

Journal of Aircraft

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“…Moreover, both experimental [21][22][23] and numerical 24,25 investigations highlight the presence of numerous shock waves in the flow over delta wings in the transonic and supersonic regimes. These shock waves can be classified in two families.…”

Section: Introductionmentioning

confidence: 98%

Compressibility effects on the vortical flow over a 65° sweep delta wing

2010

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Dynamically stretching and retracting wingspan has been widely observed in the flight of birds and bats, and its effects on the aerodynamic performance particularly lift generation are intriguing. The rectangular flat-plate flapping wing with a sinusoidally stretching and retracting wingspan is proposed as a simple model for biologically inspired dynamic morphing wings. Numerical simulations of the low-Reynolds-number flows around the flapping morphing wing are conducted in a parametric space by using the immersed boundary method. It is found that the instantaneous and time-averaged lift coefficients of the wing can be significantly enhanced by dynamically changing wingspan in a flapping cycle. The lift enhancement is caused by both changing the lifting surface area and manipulating the flow structures responsible to the vortex lift generation. The physical mechanisms behind the lift enhancement are explored by examining the three-dimensional flow structures around the flapping wing. C 2014 AIP Publishing LLC. [http://dx.

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