Instability of Rotating-Cone Boundary Layer in Axial Inflow: Effect of Cone Angle

Boundary-layer instability on a rotating cone induces coherent spiral vortices that are linked to the onset of laminar–turbulent transition. This type of transition is relevant to several aerospace systems with rotating components, e.g., aeroengine nose cones. Because a variety of options exist for the nose-cone shapes, it is important to...

Aerodynamic Performance of an Aircraft with Aft-Fuselage Boundary-Layer-Ingestion Propulsion

Boundary-layer ingestion (BLI) is a propulsor–airframe integration technology that promises substantial fuel consumption benefits for future civil aircraft. This paper discusses an experimental study, conducted within the European Union–funded Horizon 2020 CENTRELINE project, on the aerodynamic performance of an aircraft with a BLI propulsor...

Spiral instability-modes on rotating cones in high-Reynolds number axial flow

This work shows the behaviour of an unstable boundary-layer on rotating cones in high-speed flow conditions: high Reynolds number Rel > 106, low rotational speed ratio S < 1–1.5, and inflow Mach number M = 0.5. These conditions are most-commonly encountered on rotating aero-engine-nose-cones of transonic cruise aircraft. Although it has...

Aerodynamic Performance of an Aircraft with Aft-Fuselage Boundary Layer Ingestion Propulsion

View Video Presentation: https://doi-org.tudelft.idm.oclc.org/10.2514/6.2021-2467.vid<br/><br/>Boundary Layer Ingestion (BLI) is a technology that promises fuel consumption benefits for future civil aircraft. However, it introduces detrimental aerodynamic interactions between the propulsor and the airframe. In particular, the inflow to the BLI...

Boundary layer instability over a rotating slender cone under non-axial inflow

Centrifugal instability of the boundary layer is known to induce spiral vortices over a rotating slender cone that is facing an axial inflow. This paper shows how a deviation from the symmetry of such axial inflow affects the boundary layer instability over a rotating slender cone with half-angle. The spiral vortices are experimentally...

Power balance analysis experiments on an axisymmetric fuselage with an integrated boundary-layer-ingesting fan

Boundary Layer Ingestion (BLI) is a promising propulsion integration technology capable of enhancing aircraft propulsive efficiency. The Propulsive Fuselage Concept (PFC), a tube-and-wing configuration with an aft-fuselage-mounted BLI propulsor, is particularly suited for BLI. Although extensively studied on a system level, the aerodynamic...

An experimental method to investigate coherent spiral vortices in the boundary layer over rotating bodies of revolution

Abstract: Infrared thermography is applied to measure the spiral vortices in the boundary layer over a rotating cone under axial inflow. The data sets are analysed using proper orthogonal decomposition (POD). A criterion based on the signal-to-noise ratio is defined for the selection of relevant POD modes, such that a low-order reconstruction...

Coherent vortex structures over a rotating spinner under non-axial inflows at low Reynolds number

Boundary layer instabilities and the formation of coherent spiral vortices over a rotating cone and ellipsoid are studied experimentally. It is found that under a non-axial inflow, the breaking of symmetry in the flow field significantly disturbs the coherence and delays the formation of spiral vortices to higher local Reynolds numbers (Re_l)...