The characterisation of a gust generator for aerodynamic testing

Saddington, Alistair J.; Finnis, Mark; Knowles, K.

doi:10.1177/0954410014548237

Cited by 16 publications

(10 citation statements)

References 14 publications

(15 reference statements)

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“…Conventional wind tunnel-based gust rigs introduce a transverse velocity perturbation by typically one of two means. One method uses a pair or cascade of actuated vanes upstream of the model to 'turn' the incoming flow (Tang and Dowell 2010;Saddington et al 2014;Brion et al 2015;Patel and Hancock 1977;Tang et al 1996;Ham et al 1974;Patel 1982). However, this can be limited to gust ratios of approximately 0.3 due to flow separation on the vanes, coupling of the free stream velocity with vane deflection angle and increased turbulence levels.…”

Section: Gust Rigmentioning

confidence: 99%

On the development and early observations from a towing tank-based transverse wing–gust encounter test rig

2018

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Small unmanned aerial vehicles and biological fliers can experience wind gusts of similar magnitude to the flight speed, which is detrimental to flight stability. For one encounter type, the low Reynolds number transverse gust, little is known about the fundamental fluid mechanics due in part to the difficulties in replicating the scenario experimentally or computationally. The aim of this work is thus to present the development and characterisation of an apparatus capable of generating and measuring the transient response of large amplitude transverse wing-gust encounters. The system is designed to produce a sharp-edged gust profile for direct comparison with the linear Küssner model. Particle image velocimetry (PIV) measurements show that the system successfully generated a steady top-hat shaped gust. A technique using inertial sensors has been used to minimise the effects of model vibration in measuring the unsteady forces. A wing-gust interaction with cross flow velocity equal to the flight speed is also presented. For this interaction, a strong leading edge vortex forms and vorticity of opposite sense is shed at the trailing edge. The trailing edge vorticity remains relatively planar, which is similar to the planar wake assumption of the Küssner model. Large deformation of the gust shear layers is visible upon wing entry, which is a deviation from the 'rigid' shear layers assumed by linear theory. Despite differences in flow topology between theory and experiment, the lift force coefficients match surprisingly well during entry into the gust, but deviate upon exit.

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Section: Gust Rigmentioning

confidence: 99%

On the development and early observations from a towing tank-based transverse wing–gust encounter test rig

2018

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“…Approaches using arrays of six or more vanes (e.g. [9,10]) have been tested, though the wakes of the vanes introduced turbulent fluctuations into the downstream flow conditions. Simpler generation mechanisms involving two pitching plates (e.g.…”

Section: Background and Motivationmentioning

confidence: 99%

Aerodynamic Design of Airfoil Shape for Gust Generation in a Transonic Wind Tunnel

Natale¹,

Russo²,

Dequand

et al. 2021

Aerotec. Missili Spaz.

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This article presents the aerodynamic design of the airfoil of the gust generator system being developed in the GUDGET project and conceived to generate high-amplitude gusts in a transonic wind tunnel. The system is made of vanes creating a flow deviation in turn by flapping around a rotational axis or by blowing air though a suitable sonic jet located close to the vane trailing edge. The airfoil shape optimization has been carried out using a design of experiment technique (DOE) and response surface optimization along with URANS CFD. The computational model has been preliminarily validated using data provided by ONERA for the baseline design at a lower Mach number ($$\hbox {M}=0.73$$ M = 0.73 ) and then compared with the one actually required by GUDGET in the test chamber ($$\hbox {M}=0.82$$ M = 0.82 ). All the cases have been optimized at a frequency of 40 Hz and then investigated at a frequency of 80Hz.

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“…One method uses a pair or cascade of actuated vanes upstream of the model to 'turn' the incoming flow. 12,[25][26][27][28][29][30] However, this can be limited to deflection angles of 10 − 20 • due to flow separation on the vanes, coupling of the free stream velocity with vane deflection angle and increased turbulence levels. The second gust generation method involves 'jetting' flow at a fixed location and angle into the tunnel.…”

Section: A Gust Rigmentioning

confidence: 99%

Response of a Flat Plate Wing to a Transverse Gust at Low Reynolds Numbers

Corkery

Babinsky

Harvey

2018

2018 AIAA Aerospace Sciences Meeting

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In this article the unsteady response of a flat plate wing encountering a transverse gust is presented. The aim of this study is to understand how the lift and drag forces of a wing respond to a large amplitude wind gust of magnitude equivalent to the flight speed and at Reynolds numbers relevant to biological fliers and unmanned aerial vehicles. A gust rig capable of generating large amplitude top-hat shaped gust profiles was constructed in a towing tank to replicate the ideal 'sharp edge' Kussner gust. In addition, a new technique that enables vibration rejection from unsteady force measurements through improved kinematic measurements with inertial sensors is described. Measurements show that for a gust ratio of 1, a leading edge vortex forms on entry into the gust and vorticity is shed at the trailing edge in a planar manner. Large deformation of the gust shear layers is visible on wing entry, despite which linear theory is found to fit force measurements surprisingly well. Discernible differences, however, arise upon exit of the gust.

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The characterisation of a gust generator for aerodynamic testing

Cited by 16 publications

References 14 publications

On the development and early observations from a towing tank-based transverse wing–gust encounter test rig

On the development and early observations from a towing tank-based transverse wing–gust encounter test rig

Aerodynamic Design of Airfoil Shape for Gust Generation in a Transonic Wind Tunnel

Response of a Flat Plate Wing to a Transverse Gust at Low Reynolds Numbers

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