He, Wei 
ORCID: 0000-0002-2633-6114 and Timme, Sebastian ORCID: 0000-0002-2409-1686
(2020)
Triglobal Shock Buffet Instability Study on Infinite Wings.
In: AIAA Scitech 2020 Forum, 2020-1-6 - 2020-1-10.
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Abstract
Triglobal stability analysis is presented to address the question of shock-buffet unsteadiness and dominant modal behaviour on infinite wings at high Reynolds number. This contribution expands upon recent biglobal work by Crouch et al. [1], Paladini et al. [2] and Plante et al. [3] aspiring to elucidate the origin and characteristics of shock buffet on finite swept wings. Our infinite wings are modelled by extruding an OAT15A aerofoil with different physical aspect ratios and imposing a spanwise translational periodic boundary condition without assumptions on spanwise homogeneity. The flow is described by the Reynolds-averaged Navier–Stokes equations with closure via Spalart–Allmaras turbulence modelling. Flow conditions are a Mach number of 0.73, a chord Reynolds number of 3.2 × 106 and different angles of attack around instability onset. The critical angle of attack is approximately 3.4◦, similar to previous aerofoil results in Sartor et al. [4]. Two distinct steady base flows, spanwise parallel and non-parallel, are analysed herein on straight and swept wings. Triglobal stability analysis of the spanwise parallel flow on the infinite-straight wing with aspect ratio three identifies both an unstable oscillatory mode, linked to the spanwise-uniform chordwise shock motion synchronised with a pulsation of its downstream shear layer, and several monotone (non-oscillatory) spanwise-periodic shock-distortion modes. Those monotone modes become oscillatory and outboard travelling on the swept wings with their frequencies and phase speeds correlated to the sweep angle. In non-parallel flow on straight wings of different aspect ratios, two dominant three-dimensional modes are found, both stable and unstable depending on aspect ratio. Non-linear time-marching simulations confirm the insights gained from linear stability analysis.
| Item Type: | Conference or Workshop Item (Unspecified) |
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| Depositing User: | Symplectic Admin |
| Date Deposited: | 12 Dec 2019 08:30 |
| Last Modified: | 19 Jan 2023 00:13 |
| DOI: | 10.2514/6.2020-1986 |
| Related URLs: | |
| URI: | https://livrepository.liverpool.ac.uk/id/eprint/3066003 |
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