Surface pressure model for simple delta wings at high angles of attack

Pashilkar, AA

doi:10.1007/bf02703456

Cited by 2 publications

(2 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Interestingly, vortex flows above delta wings migrate vertically above the wing as they travel along the chord of the wing. Consequently pressures directly below the vortex cores increase posteriorly (Zohar and Er-El, 1988;Pashilkar, 2001). This was also observed along the bodies of boxfishes.…”

Section: Lift Coefficients and Delta Wingsmentioning

confidence: 84%

Body-induced vortical flows: a common mechanism for self-corrective trimming control in boxfishes

Bartol

Gharib

Webb

et al. 2005

Journal of Experimental Biology

View full text Add to dashboard Cite

SUMMARY Boxfishes (Teleostei: Ostraciidae) are marine fishes having rigid carapaces that vary significantly among taxa in their shapes and structural ornamentation. We showed previously that the keels of the carapace of one species of tropical boxfish, the smooth trunkfish, produce leading edge vortices (LEVs) capable of generating self-correcting trimming forces during swimming. In this paper we show that other tropical boxfishes with different carapace shapes have similar capabilities. We conducted a quantitative study of flows around the carapaces of three morphologically distinct boxfishes(spotted boxfish, scrawled cowfish and buffalo trunkfish) using stereolithographic models and three separate but interrelated analytical approaches: digital particle image velocimetry (DPIV), pressure distribution measurements, and force balance measurements. The ventral keels of all three forms produced LEVs that grew in circulation along the bodies, resembling the LEVs produced around delta-winged aircraft. These spiral vortices formed above the keels and increased in circulation as pitch angle became more positive,and formed below the keels and increased in circulation as pitch angle became more negative. Vortices also formed along the eye ridges of all boxfishes. In the spotted boxfish, which is largely trapezoidal in cross section, consistent dorsal vortex growth posterior to the eye ridge was also present. When all three boxfishes were positioned at various yaw angles, regions of strongest concentrated vorticity formed in far-field locations of the carapace compared with near-field areas, and vortex circulation was greatest posterior to the center of mass. In general, regions of localized low pressure correlated well with regions of attached, concentrated vorticity, especially around the ventral keels. Although other features of the carapace also affect flow patterns and pressure distributions in different ways, the integrated effects of the flows were consistent for all forms: they produce trimming self-correcting forces, which we measured directly using the force balance. These data together with previous work on smooth trunkfish indicate that body-induced vortical flows are a common mechanism that is probably significant for trim control in all species of tropical boxfishes.

show abstract

Section: Lift Coefficients and Delta Wingsmentioning

confidence: 84%

Body-induced vortical flows: a common mechanism for self-corrective trimming control in boxfishes

Bartol

Gharib

Webb

et al. 2005

Journal of Experimental Biology

View full text Add to dashboard Cite

show abstract

“…The increment of angle of attack of a delta wing [31] causes to increase aeroelastic resonant frequencies. Pashilkar [32] investigates a surface pressure model for observing aeroelastic responses of delta wing for high angles of attack conditions. Gordnier and Visbal [17] examine aeroelastic spectral analysis of wing deflection for a delta wing that the first structural mode has dominant effect between an angle of attack range of 50 and 400.…”

Section: Introductionmentioning

confidence: 99%

Investigation of Flow Characteristics and Vortex Formations of Lambda Wing at High Angles of Attack

Yavuz¹

2020

Journal of Thermal Engineering

View full text Add to dashboard Cite

It is well known in literature that further stages of flow separation and vortex breakdown around wings can be able to cause stall of wings. These formations must be investigated carefully for new plane types. However, some limited studies are available, especially on lambda wing for high angles of attack. In this study, effect of angle of attack on flow characteristics and vortex breakdown around a lambda wing is investigated with a constant Reynolds number of 10000. Computational fluid dynamic analysis is used and results of high angles of attack of the wing are given up to 45 0 which are not available in literature. Open water channel simulation is used. Vortex breakdown initially begins at an angle of 17 0 and it almost reaches to tip of wing when angle of attack is equal to 25 0. Vortices get stronger at further increments of angle of attack and they become to nearly equal length of wing at 45 0. Rounding effect of leading edges is investigated for decreasing vortex magnitudes. Streamline, particle injection, iso-value of vortices and location of stagnation points are given, and they are discussed in detail.

show abstract

Surface pressure model for simple delta wings at high angles of attack

Cited by 2 publications

References 30 publications

Body-induced vortical flows: a common mechanism for self-corrective trimming control in boxfishes

Body-induced vortical flows: a common mechanism for self-corrective trimming control in boxfishes

Investigation of Flow Characteristics and Vortex Formations of Lambda Wing at High Angles of Attack

Contact Info

Product

Resources

About