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Onset of unsteadiness in aero-engine intakes at incidence

Coschignano, A and Babinsky, H and Sheaf, C and Platt, E (2016) Onset of unsteadiness in aero-engine intakes at incidence. In: 55th AIAA Aerospace Sciences Meeting, AIAA Science and Technology Forum and Exposition 2017, -- to --.

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© 2017 by Andrea Coschignano. The flow field around a transonic engine inlet lip at high incidence is investigated for a variety of flow conditions around the design point. Generally, the flow on the upper surface of the lip is characterised by a supersonic region, terminated by a near-normal shock wave. At the nominal design point, the shock is not strong enough to cause significant flow separation for each of the shapes investigated. Off-design conditions were explored by altering the angle of attack as well as changing the mass flow rate over the upper lip, intended to mimic a greater mass flow demand by a turbofan engine. The results suggest that angle of attack is the dominant parameter, where an even relatively small increase of 2° can lead to large and highly unsteady flow separation with an associated shock oscillation. This is a consequence of the significantly stronger shock compared to the on design case. Both qualitative and quantitative measurements suggest a noticeably reduced aerodynamic performance resulting from higher incidence operation. In contrast, an increase of up to 5.2% in mass flow did not result in large separated regions or flow field unsteadiness. Hflowever, a trend of increasing separation with greater mass flow was observed.

Item Type: Conference or Workshop Item (UNSPECIFIED)
Divisions: Div A > Fluid Mechanics
Depositing User: Cron Job
Date Deposited: 17 Jul 2017 19:26
Last Modified: 22 May 2018 07:36