The junction flows formed between a wing and a wall are ubiquitous in engineering applications and are known to impact aerodynamic performance and energy consumption. This paper studies the mean pressure field in the junction region around a wall-mounted wing with a NACA 0012 and NACA 6412 airfoil section profile. Mean surface pressure measurements have been performed in the UNSW Large Aerodynamic Wind Tunnel at a chord-based Reynolds number of 87,000 and a range of angles of attack spanning 20 degrees. Results of two-dimensional numerical simulation cases for both airfoil profiles at different angles of attack are presented for comparisons. The presence of the wall-mounted airfoil is observed to significantly change the surrounding mean pressure distribution and the evolution of the flow. These results are useful not only for understanding the loading of aircraft fuselages and marine hulls, but also to provide a validation dataset for computational modelling.
In this study, the far-field acoustics and near-field flow characterizing vortex formation at a wing tip has been investigated experimentally. Measurements have been taken on a rectangular planform NACA 0012 wing with a flat tip and an aspect ratio (span-to-chord ratio) of π΄π = π /π = 2 at a Reynolds number of π π = 1.5 Γ 10 4 , and a geometric angle of attack of πΌ = 5 β’ in the UNSW anechoic wind tunnel. Acoustic beamforming results obtained with a planar 64-microphone array show that tip noise is a prominent airfoil noise source at mid to high frequencies (3.7 to 11.5 kHz), corresponding to chord-based Strouhal numbers of ππ‘ π = π π/π β = 8 β 25. Stereoscopic Particle Image Velocimetry measurements reveal information about the size and location of the tip vortex in the near wake. In the vortex core, the axial velocity has a wake-like profile with a velocity deficit of 24%. Snapshot Proper Orthogonal Decomposition is used to extract the dominant coherent structures, which reveals that the two most energetic modes are found to consist of a coherent structure pair within the vortex core region. The unsteady surface pressure field over the wing tip is measured using the remote microphone technique. High magnitude pressure fluctuations are observed near the trailing edge on the tip surface and on the airfoil suction side that may be associated with the tip noise source.
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