Devices and methods for guiding bleed air in a turbofan engine

A turbofan engine comprising:

• a core engine having an axial direction relative to a central axis of the turbofan engine and a radial direction perpendicular to the axial direction;
• an inner casing in which the core engine is disposed;
• a bypass duct defined between the inner casing and an outer casing;
• and
• a louver defining part of a bleed air passage extending between the core engine and the bypass duct via an opening through the inner casing, the louver including:
• a first portion defining a flow-guiding surface at least partially defining the bleed air passage, the flow-guiding surface having an upstream end and a downstream end, the first portion having a first camber line extending from a leading edge of the louver to a trailing end of the first portion;
• and
• a second portion extending from the trailing end of the first portion to a trailing edge of the second portion, the second portion adjacent the downstream end of the flow-guiding surface and protruding into the bleed air passage to obstruct a flow of bleed air guided by the flow-guiding surface of the first portion,
• wherein:
• the second portion has a second camber line that intersects the first camber line and forms a discontinuity in tangency with the first camber line at an intersection of the first camber line with the second camber line;
• the second camber line extends from the intersection to the trailing edge of the second portion;
• the leading edge of the louver is axially forward of the intersection and axially forward of the trailing edge of the second portion:
• the leading edge of the louver is radially inward of the intersection and radially inward of the trailing edge of the second portion;
• and
• the trailing edge of the second portion is radially inward of the intersection.

A method of guiding bleed air in a turbofan engine having:

• a core engine;
• a bypass duct;
• and
• a louver for guiding the bleed air from the core engine into the bypass duct of the turbofan engine, the louver including:
• an axial direction relative to a central axis of the turbofan engine and a radial direction perpendicular to the axial direction;
• a first portion defining a flow-guiding surface at least partially defining a bleed air passage, the first portion having a first camber line extending from a leading edge of the louver to a trailing end of the first portion;
• and
• a second portion extending from the trailing end of the first portion to a trailing edge of the second portion, the second portion protruding into the bleed air passage and having a second camber line that intersects the first camber line and forms a discontinuity in tangency with the first camber line at an intersection of the first camber line with the second camber line, the second camber line extending from the intersection to the trailing edge of the second portion,
• wherein:
• the leading edge of the louver is axially forward of the intersection and axially forward of the trailing edge of the second portion;
• the leading edge of the louver is radially inward of the intersection and radially inward of the trailing edge of the second portion;
• and
• the trailing edge of the second portion is radially inward of the intersection,
• the method comprising:
• guiding the bleed air received from the core engine with the louver toward a bypass flow direction of bypass air flowing into the bypass duct;
• after guiding the bleed air toward the bypass flow direction, causing, with the louver, the bleed air to swerve;
• and
• after causing the bleed air to swerve, discharging the bleed air into the bypass duct.