Reverse thrust engine

An engine defining a central axis, the engine comprising:

• a fan section including a plurality of variable pitch fan blades for generating a forward thrust and a reverse thrust;
• a core engine drivingly connected to the fan section;
• and
• a core casing enclosing the core engine and at least partially defining a primary air flowpath through the core engine, the core casing extending along the central axis from a forward end to an aft end, the core casing defining an annular inlet to the primary air flowpath at the forward end and a reverse flow passage extending through the core casing to the primary air flowpath to allow a flow of air into the primary air flowpath at a location forward of a low pressure compressor when the variable pitch fan blades generate a reverse thrust, wherein an inner surface exit is defined through an inner surface of the core casing and at least partially through a core strut forward of the low pressure compressor, and wherein the reverse flow passage further comprises:
• an outer surface entrance defined through an outer surface of the core casing, wherein the outer surface entrance is defined aft of a bypass outlet guide vane and forward of at least a portion of the low pressure compressor.

A method of operating a propulsion device having a fan section with a plurality of variable pitch fan blades for generating a forward thrust and a reverse thrust, a core engine drivingly connected to the fan section, and a core casing, the method comprising:

• generating reverse thrust utilizing the fan section such that air flows through a reverse flow passage, wherein the reverse flow passage is defined through the core casing, and wherein the core casing encloses the core engine and at least partially defines a primary air flowpath through the core engine, the core casing extending along a central axis from a forward end to an aft end, the core casing defining an annular inlet to the primary air flowpath at the forward end, wherein the core casing has an inner surface and outer surface;
• articulating an active control plate with an obstruction so as to remove the obstruction from the reverse flow passage, wherein the reverse flow passage defines an arcuate flowpath through the core casing, wherein the active control plate is positioned within and at least partially aft of the arcuate flowpath;
• and
• delivering a portion of reverse airflow through the reverse flow passage defined by the core casing and extending from an outer surface entrance to an inner surface exit, wherein the inner surface exit is defined through the inner surface, wherein the inner surface exit is defined aft of a core strut and forward of a low pressure compressor, and wherein the outer surface entrance is defined through the outer surface, wherein the outer surface entrance is defined aft of a bypass outlet guide vane and forward of at least a portion of the low pressure compressor.