Supersonic engine inlet diffuser with deployable vortex generators

摘要

A flow control device generates counter-rotating vortices in the boundary layer of the flow in a supersonic inlet diffuser for an aircraft turbine engine. The flow control device comprises a flap attached to the duct wall for selective deployment, wherein it extends into the boundary layer, and retraction, wherein it lies substantially flush with the duct wall. In one embodiment an actuating mechanism comprising one or more shape-memory alloy wires moves the flap between two stable positions. In another embodiment the deployment height of the flap can be controlled as desired, preferably using a shape-memory alloy actuating mechanism. Typically, an array of plural flow control devices is disposed in the inlet duct for selective actuation according to a predetermined schedule.

主权项

1. An inlet diffuser for introducing air flow to a turbine engine, the diffuser comprising:
an inlet duct having a portion bounded by mutually facing duct walls for accepting air traveling at a velocity in excess of the speed of sound in the air (M >1) and passing air flow traveling in said duct at M >1 through a shock front between said facing duct walls at a location in said inlet duct upstream of the turbine engine to decelerate the air flow to a velocity less than the speed of sound in the air (M <1), wherein a boundary layer proximate to at least one duct wall of said facing duct walls interacts with the shock front; an array of a plurality of flow control devices disposed upstream of said location and arranged over an area of said at least one duct wall within said portion of said inlet duct, each of said plurality of flow control devices including a flap having a first portion attached to said at least one duct wall and an active portion movable between (i) a retracted position wherein said active portion is substantially flush with a region of said at least one duct wall adjacent said flap for minimizing disturbance of air flow in a boundary layer trailing each of said flow control devices, and (ii) a deployed position wherein said active portion extends a predetermined height above said region of said at least one duct wall for altering air flow in the boundary layer trailing each of said flow control devices that interacts with the shock front; and an actuating mechanism including a shape-memory alloy actuating member, said actuating mechanism being operatively connected to said flaps for deforming at least one of said flaps to effect movement of said active portion thereof between the retracted position and the deployed position.