초록 ▼

An aircraft propulsive power unit having an engine (20), a nacelle structure (12) which houses the engine (20) and which has an exterior low drag boundary surface (16) which is subjected to exterior air flow in a boundary layer adjacent the boundary surface (16) and an air flow disruption device (19

An aircraft propulsive power unit having an engine (20), a nacelle structure (12) which houses the engine (20) and which has an exterior low drag boundary surface (16) which is subjected to exterior air flow in a boundary layer adjacent the boundary surface (16) and an air flow disruption device (19) activatable to cause at a control location in the boundary surface disruption of exterior air flow in the boundary layer at the control location without reversal or deflection of engine thrust gaseous flow. Where the power unit is a turbofan and the nacelle structure includes a fan duct (22) with inner and outer fan duct walls (25,26) the air flow disruption device (19) is additionally or alternatively activatable to cause at a control location in the outer fan duct wall (26) disruption of air flow in the boundary layer at the control location.

대표청구항 ▼

[ What is claimed is:] [1.] An aircraft propulsive power unit comprising a core engine and a fan driven by the core engine, a nacelle structure which (i) houses the core engine and fan, (ii) has an exterior low drag boundary surface which extends from an upstream region to a downstream trailing edge

[ What is claimed is:] [1.] An aircraft propulsive power unit comprising a core engine and a fan driven by the core engine, a nacelle structure which (i) houses the core engine and fan, (ii) has an exterior low drag boundary surface which extends from an upstream region to a downstream trailing edge region and which is subjected to exterior air flow in a boundary layer adjacent the boundary surface and (iii) includes an annular fan duct (a) within which the fan is mounted, (b) through which air from the fan is conveyed, and (c) which has inner and outer fan duct walls which extend to a discharge end of the fan duct and which are subjected to boundary layer fan duct air flow, characterized by the provision of exterior air flow disruption means activatable to cause at an exterior air flow control location in the boundary surface upstream of the trailing edge region disruption of exterior air flow in the boundary layer at the exterior air flow control location without reversal or deflection of engine thrust gaseous flow and fan duct air flow control means activatable to cause at a fan duct air flow control location in the outer fan duct wall upstream of the discharge end of the fan duct disruption of fan duct boundary layer air flow at the fan duct air flow control location, disruption of the exterior air flow being such as to cause or just sufficient to cause separation of the exterior air flow boundary layer at or downstream of the exterior air flow control location.