A Numerical Investigation of the Geometric Parametrisation of Shock Control Bumps for Transonic Shock Oscillation Control
Autor: | Gareth A. Vio, Jack A. Geoghegan, Nicholas F. Giannelis |
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Jazyk: | angličtina |
Rok vydání: | 2020 |
Předmět: |
Airfoil
02 engineering and technology Reynolds-averaged Navier–Stokes simulation lcsh:Thermodynamics 01 natural sciences shock control bumps 010305 fluids & plasmas 0203 mechanical engineering Flight envelope lcsh:QC310.15-319 0103 physical sciences transonic aerodynamics Envelope (mathematics) lcsh:QC120-168.85 Fluid Flow and Transfer Processes Physics Flow control (data) 020301 aerospace & aeronautics Oscillation Mechanical Engineering Aerodynamics Mechanics Condensed Matter Physics flow control Shock (mechanics) transonic shock buffet lcsh:Descriptive and experimental mechanics Transonic |
Zdroj: | Fluids Volume 5 Issue 2 Fluids, Vol 5, Iss 46, p 46 (2020) |
ISSN: | 2311-5521 |
DOI: | 10.3390/fluids5020046 |
Popis: | At transonic flight conditions, shock oscillations on wing surfaces are known to occur and result in degraded aerodynamic performance and handling qualities. This is a purely flow-driven phenomenon, known as transonic buffet, that causes limit cycle oscillations and may present itself within the operational flight envelope. Hence, there is significant research interest in the development of shock control techniques to either stabilise the unsteady flow or raise the boundary onset. This paper explores the efficacy of dynamically activated contour-based shock control bumps within the buffet envelope of the OAT15A aerofoil on transonic flow control numerically through unsteady Reynolds-averaged Navier&ndash Stokes modelling. A parametric evaluation of the geometric variables that define the Hicks&ndash Henne-derived shock control bump will show that bumps of this type lead to a large design space of applicable shapes for buffet suppression. Assessment of the flow field, local to the deployed shock control bump geometries, reveals that control is achieved through a weakening of the rear shock leg, combined with the formation of dual re-circulatory cells within the separated shear-layer. Within this design space, favourable aerodynamic performance can also be achieved. The off-design performance of two optimal shock control bump configurations is explored over the buffet region for M = 0 . 73 , where the designs demonstrate the ability to suppress shock oscillations deep into the buffet envelope. |
Databáze: | OpenAIRE |
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