Abstract: A method for scavenging small particles from a turbine engine includes directing compressed air through a flowpath, downstream of a compressor, which causes a reduction in a radial flow component and the introduction of or an increase in an axial flow component of the compressed air, removing a portion of the compressed air from the flowpath and directing the portion into a scavenge plenum, the scavenge plenum being positioned adjacent to and radially outward from the flowpath, and returning the portion of the compressed air from the plenum to the flowpath while maintaining a majority of the small particles that were present in the portion within the scavenge plenum. Further, the method includes removing the majority of small particles from the plenum. The step of removing occurs intermittently during engine operation, during engine shutdown, or while the engine is not in operation, but does not occur continuously during engine operation.

Abstract: An inlet particle separator system for a gas turbine engine includes a separator manifold. The separator manifold includes an inlet upstream from an outlet. The inlet is to receive an incoming airflow, and the outlet is to be fluidly coupled to an inlet of the gas turbine engine. The inlet particle separator system includes at least one dry fog nozzle coupled proximate the inlet so as to face at least partially away from the inlet. The dry fog nozzle is external to the separator manifold, and the dry fog nozzle is to direct a spray of dry fog in a direction transverse to the incoming airflow to agglomerate with fine particles in the incoming airflow to form agglomerated particles. The inlet particle separator system includes a scavenging system coupled to the separator manifold downstream from the inlet, and the scavenging system removes the agglomerated particles from the separator manifold.

Abstract: A gas turbine engine includes a combustion section that generates combustive gases that form a primary exhaust flow and an exhaust system downstream from the combustion section. The exhaust system includes an eductor system that includes a body that extends along a first axis, and a plurality of ducts spaced apart about a circumference of the body. Each of the plurality of ducts define a plurality of eductor primary flow paths that terminate in a mixing chamber. The exhaust system includes a muffler system downstream from the mixing chamber that includes a plurality of baffles that cooperate to define a tortuous path and attenuate sound generated by the gas turbine engine. The exhaust system includes a housing that surrounds the eductor system and the muffler system such that the eductor system and the muffler system are contained within the housing.

Abstract: A particle separator includes a housing defining an inlet and an outlet. A flow stream is directed from the inlet to the outlet. A number of dividers are disposed in the housing and separate flow channels from each other. The flow channels extend from the inlet to the outlet. The dividers each have a profile so that the flow channels follow the profile. The dividers each include a plurality of cavities that open to each of the flow channels and that have blind ends. The cavities each have an aspect ratio greater than one, and are configured to collect particles from the flow stream.

Abstract: Airfield guidance signs are described herein. One airfield guidance sign includes a first surface, a second surface angled with respect to the first surface, and a top edge adjacent the first surface and the second surface, wherein the top edge is rounded to reduce a pressure differential between the first surface and the second surface when a force is applied to the first surface or the second surface.

Abstract: Systems and methods for an exhaust system for a gas turbine engine are provided. The method includes: receiving a primary exhaust fluid in a primary manifold; receiving a secondary cooling fluid in a secondary plenum; directing the primary exhaust fluid through a plurality of eductor primary flow paths associated with a respective plurality of ducts spaced circumferentially about a primary manifold, the plurality of eductor primary flow paths extending through the secondary plenum; and mixing the primary exhaust fluid and the secondary cooling fluid in a mixing chamber associated with a respective one of the plurality of ducts to create a mixed fluid flow.

Abstract: An inlet particle separator system for a gas turbine engine includes a separator manifold. The separator manifold includes an inlet upstream from an outlet. The inlet is to receive an incoming airflow, and the outlet is to be fluidly coupled to an inlet of the gas turbine engine. The inlet particle separator system includes at least one dry fog nozzle coupled proximate the inlet so as to face at least partially away from the inlet. The dry fog nozzle is external to the separator manifold, and the dry fog nozzle is to direct a spray of dry fog in a direction transverse to the incoming airflow to agglomerate with fine particles in the incoming airflow to form agglomerated particles. The inlet particle separator system includes a scavenging system coupled to the separator manifold downstream from the inlet, and the scavenging system removes the agglomerated particles from the separator manifold.

Abstract: An inertial inlet particle separator system for a vehicle engine is provided. A separator assembly and collector assembly are coupled to the scavenge flow path and configured to receive the scavenge air. The collector inlet has a throat defining a cumulative throat area at each position along the throat length from the first throat end to the second throat end. The collector body defines a cross-sectional area associated with each position along the throat length between the first throat end and the second throat end. The collector outlet is coupled to the collector body such that scavenge air flows into the collector inlet, through the collector body, and out through the collector outlet. At a first position between the first throat end and the second throat end, the respective cross-sectional area of the collector body is greater than or equal to the respective cumulative throat area.

Abstract: Airfield guidance signs are described herein. One airfield guidance sign includes a first surface, a second surface angled with respect to the first surface, and a top edge adjacent the first surface and the second surface, wherein the top edge is rounded to reduce a pressure differential between the first surface and the second surface when a force is applied to the first surface or the second surface.

Abstract: A method for scavenging small particles from a turbine engine includes directing compressed air through a flowpath, downstream of a compressor, which causes a reduction in a radial flow component and the introduction of or an increase in an axial flow component of the compressed air, removing a portion of the compressed air from the flowpath and directing the portion into a scavenge plenum, the scavenge plenum being positioned adjacent to and radially outward from the flow path, and returning the portion of the compressed air from the plenum to the flowpath while maintaining a majority of the small particles that were present in the portion within the scavenge plenum. Further, the method includes removing the majority of small particles from the plenum. The step of removing occurs intermittently during engine operation, during engine shutdown, or while the engine is not operation, but does not occur continuously during engine operation.

Abstract: A particle separator includes a housing defining an inlet and an outlet. A flow stream is directed from the inlet to the outlet. A number of dividers are disposed in the housing and separate flow channels from each other. The flow channels extend from the inlet to the outlet. The dividers each have a profile so that the flow channels follow the profile. The dividers each include a plurality of cavities that open to each of the flow channels and that have blind ends. The cavities each have an aspect ratio greater than one, and are configured to collect particles from the flow stream.

Abstract: A flow control system in an inlet duct to a heat exchanger includes a door having a first end and a second end opposite the first end. The first end rotates about an axis and the second end moves between an open position and a closed position to respectively allow and prevent flow into the heat exchanger. The second end has a rounded configuration. A plurality of mixing elements are downstream of the door. At least one mixing element has a base portion and a distal portion, and the base portion has a base width and the distal portion has a distal width. The base width is wider that the distal width.

Abstract: A gas turbine engine includes a combustion section that generates combustive gases that form a primary exhaust flow and an exhaust system downstream from the combustion section. The exhaust system includes an eductor system that includes a body that extends along a first axis, and a plurality of ducts spaced apart about a circumference of the body. Each of the plurality of ducts define a plurality of eductor primary flow paths that terminate in a mixing chamber. The exhaust system includes a muffler system downstream from the mixing chamber that includes a plurality of baffles that cooperate to define a tortuous path and attenuate sound generated by the gas turbine engine. The exhaust system includes a housing that surrounds the eductor system and the muffler system such that the eductor system and the muffler system are contained within the housing.

Abstract: An outflow valve is provided. The outflow valve includes a frame and a first door rotatably coupled to the frame. The first door has a first side opposite a second side and a bellmouth. The bellmouth is defined by a super-ellipse, with a major axis of the super-ellipse substantially parallel to the second side and a minor axis of the super-ellipse substantially perpendicular to the second side. The outflow valve also includes a second door rotatably coupled to the frame. The first door and the second door are substantially simultaneously movable between at least a first position and a second position.

Abstract: A turbine engine incorporating a fine particle separation means includes a radial compressor that rotates about a longitudinal axis, a radially-oriented diffuser located downstream and radially outward, with respect to the longitudinal axis, from the radial compressor, and a flow path positioned downstream and radially outward, with respect to the longitudinal axis, from the diffuser, wherein the flow path comprises an outer annular wall and an inner annular wall between which the compressed air flows, and wherein the flow path comprises an arc the redirects the compressed air from flowing in a substantially radial flow direction to a substantially axial flow direction. The turbine engine further includes an extraction slot in the outer annular wall that fluidly connects with a scavenge plenum, the scavenge plenum being positioned adjacent to and radially outward from the outer annular wall at a position downstream axially along the flow path from the arc.

Abstract: An inertial inlet particle separator system for a vehicle engine is provided. A separator assembly and collector assembly are coupled to the scavenge flow path and configured to receive the scavenge air. The collector inlet has a throat defining a cumulative throat area at each position along the throat length from the first throat end to the second throat end. The collector body defines a cross-sectional area associated with each position along the throat length between the first throat end and the second throat end. The collector outlet is coupled to the collector body such that scavenge air flows into the collector inlet, through the collector body, and out through the collector outlet. At a first position between the first throat end and the second throat end, the respective cross-sectional area of the collector body is greater than or equal to the respective cumulative throat area.

Abstract: Systems and methods for an exhaust system for a gas turbine engine are provided. The exhaust system includes an eductor system adapted to receive a primary exhaust fluid. The eductor system includes a body that extends along a first axis, with a plurality of ducts spaced apart about a circumference of the body. Each of the plurality of ducts extend from the body along a second axis transverse to the first axis to define a plurality of eductor primary flow paths that terminate in a mixing chamber. The mixing chamber is adapted to receive a secondary cooling fluid and to mix the primary exhaust fluid with the secondary cooling fluid to create a mixed fluid flow.

Abstract: An inertial inlet particle separator system for a vehicle engine is provided. A separator assembly and collector assembly are coupled to the scavenge flow path and configured to receive the scavenge air. The collector inlet has a throat defining a cumulative throat area at each position along the throat length from the first throat end to the second throat end. The collector body defines a cross-sectional area associated with each position along the throat length between the first throat end and the second throat end. The collector outlet is coupled to the collector body such that scavenge air flows into the collector inlet, through the collector body, and out through the collector outlet. At a first position between the first throat end and the second throat end, the respective cross-sectional area of the collector body is greater than or equal to the respective cumulative throat area.

Abstract: Systems and methods for an exhaust system for a gas turbine engine are provided. The method includes: receiving a primary exhaust fluid in a primary manifold; receiving a secondary cooling fluid in a secondary plenum; directing the primary exhaust fluid through a plurality of eductor primary flow paths associated with a respective plurality of ducts spaced circumferentially about a primary manifold, the plurality of eductor primary flow paths extending through the secondary plenum; and mixing the primary exhaust fluid and the secondary cooling fluid in a mixing chamber associated with a respective one of the plurality of ducts to create a mixed fluid flow.

Abstract: An inlet particle separator system for a vehicle engine includes a hub section, a shroud section, and a splitter. The hub section has a hub outer surface that diverges, relative to the axis of symmetry, to a hub apex. The shroud section has a shroud inner surface that surrounds, and is spaced apart from, at least a portion of the hub section to define a main flow passageway between the hub outer surface and the shroud inner surface. The splitter is disposed downstream of the air inlet and extends into the main flow passageway to divide the main flow passageway into a scavenge flow path and an engine flow path. The hub section and the shroud section are configured such that the cross sectional flow area of the main flow passageway decreases downstream of the air inlet to define a throat section that is disposed upstream of the hub apex.