Near-field wing tip vortex measurements via PIV

The near-field (up to three chord lengths) development of a wing-tip vortex is investigated both numerically and experimentally. The research was conducted in a medium speed wind tunnel on a NACA 0012 square tip half-wing at a Reynolds number of 3.2 × 105. A full Reynolds stress turbulence model with a hybrid unstructured grid was used to compute the wing-tip vortex in the near field while an x-wire anemometer and five-hole probe recorded the experimental results. The mean flow of the computed vortex was in good agreement with experiment as the circulation parameter was within 6% of the experimental value at x/ c = 0 for α = 10° and the crossflow velocity magnitude was within 1% of the experimental value at x/ c = 1 for α = 5°. The trajectory of the computed vortex was also in good agreement as it had moved inboard by the same amount (10% chord) as the experimental vortex at the last measurement location. The axial velocity excess is under predicted for α = 10°, whereas the velocity deficit is in relatively good agreement for α = 5°. The computed Reynolds shear stress component 〈 u′v′〉 is in good agreement with experiment at x/ c = 0 for α = 5°, but is greatly under predicted further downstream and at all locations for α = 10°. It is thought that a lack of local grid refinement in the vortex core and deficiencies in the Reynolds stress turbulence model may have led to errors in the mean flow and turbulence results respectively.

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High-Order LES for Wing Tip Vortex in the Near Field

43rd AIAA Aerospace Sciences Meeting and Exhibit ◽

10.2514/6.2005-1125 ◽

2005 ◽

Cited By ~ 2

Author(s):

Jiangang Cai ◽

Shutian Deng ◽

Peng Xie ◽

Chaoqun Liu

Keyword(s):

Near Field ◽

High Order ◽

Tip Vortex ◽

Wing Tip Vortex ◽

Wing Tip

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Experimental study on the near field structure of wing-tip vortex

10.2514/6.2000-792 ◽

2000 ◽

Author(s):

Sejong Oh ◽

Sangjun Jung

Keyword(s):

Experimental Study ◽

Near Field ◽

Field Structure ◽

Tip Vortex ◽

Wing Tip Vortex ◽

Wing Tip

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Detached-eddy simulation of wing-tip vortex in the near field of NACA 0015 airfoil

Journal of Hydrodynamics ◽

10.1016/s1001-6058(14)60022-6 ◽

2014 ◽

Vol 26 (2) ◽

pp. 199-206 ◽

Cited By ~ 7

Author(s):

Zhi-cheng Liang ◽

Lei-ping Xue

Keyword(s):

Near Field ◽

Tip Vortex ◽

Detached Eddy Simulation ◽

Eddy Simulation ◽

Wing Tip Vortex ◽

Naca 0015 ◽

Wing Tip

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Dynamics of the wing-tip vortex in the near field of a NACA 0012 aerofoil

The Aeronautical Journal ◽

10.1017/s0001924000005686 ◽

2011 ◽

Vol 115 (1166) ◽

pp. 229-239 ◽

Cited By ~ 27

Author(s):

C. del Pino ◽

J.M. López-Alonso ◽

L. Parras ◽

R. Fernandez-Feria

Keyword(s):

Unstable Mode ◽

Near Field ◽

Reynolds Numbers ◽

Tip Vortex ◽

Vortex Centre ◽

Wing Tip Vortex ◽

Spatio Temporal ◽

Naca 0012 ◽

Proper Orthogonal ◽

Wing Tip

AbstractThe dynamics of the wing tip vortex in the near-field of a NACA 0012 aerofoil has been analysed by means of flow visualisations in a water tunnel. Different axial distances near the wing up to four chords, Reynolds numbers up to 42,000 and three angles-of-attack are studied to characterise the behaviour of the vortex meandering. The spatio-temporal vortex centre positions show distorted elliptical shapes in a (x,y)-plane. The Reynolds number has no significant influence on the axial evolution of the meandering amplitude. In addition, the flow visualisations obtained with a low speed camera are analysed by the singular value or proper orthogonal decomposition. Thus, the most energetic displacement modes are obtained. The frequency associated to these modes is computed byFFT. In all the cases studied, our results show that the most unstable mode corresponds to the azimuthal wavenumber |n| = 1 in the so-called Kelvin helical modes and the frequency is lower or close to 1Hz.

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