A thrust reverser of a propulsion system nacelle is provided. The thrust reverser includes a fixed structure, a translating structure, and an aerodynamic feature. The fixed structure includes an annular wall that partially defines an annular bypass airstream duct. The fixed structure is bifurcated into left and right side sections. The annular wall extends between upper and lower bifurcation walls of the left side section, and extends between upper and lower bifurcation walls of the right side section. The translating structure is moveable relative to the fixed structure, between a stowed position and a deployed position. The aerodynamic feature that includes a flange disposed relative to an aft end portion of one of the lower bifurcation walls. The flange aids in preventing aerodynamic drag.

Jet engine gas lasers are disclosed. A disclosed example apparatus includes a jet engine, and first and second opposing mirrors exposed to an exhaust gas flow path of the jet engine, where at least one mirror of the first and second opposing mirrors is adjustable to generate laser light energy using exhaust gas of the jet engine.

Jet engine gas lasers are disclosed. A disclosed example apparatus includes a jet engine, and first and second opposing mirrors exposed to an exhaust gas flow path of the jet engine, where at least one mirror of the first and second opposing mirrors is adjustable to generate laser light energy using exhaust gas of the jet engine.

A method of making a light weight component is provided. The method including the steps of: forming a metallic foam core into a desired configuration; and applying an external metallic shell to an exterior surface of the metallic foam core after it has been formed into the desired configuration.

A nacelle for a gas turbine engine includes a ring shaped body defining a center axis and having a radially outward surface and a radially inward surface. An aft portion of the radially inward surface includes an axially extending convergent-divergent exit nozzle. An axially extending secondary duct passes through the nacelle in the convergent-divergent exit nozzle. The axially extending secondary duct includes an inlet at a convergent portion of the convergent-divergent exit nozzle and an outlet at a divergent portion of the convergent-divergent exit nozzle.

A nacelle for a gas turbine engine includes a ring shaped body defining a center axis and having a radially outward surface and a radially inward surface. An aft portion of the radially inward surface includes an axially extending convergent-divergent exit nozzle. An axially extending secondary duct passes through the nacelle in the convergent-divergent exit nozzle. The axially extending secondary duct includes an inlet at a convergent portion of the convergent-divergent exit nozzle and an outlet at a divergent portion of the convergent-divergent exit nozzle.

Provided are an exhaust duct, an exhaust duct assembly, and an aircraft using the exhaust duct. The exhaust duct has a structure that enables combustion gas to be diverged and discharged from an inlet end to a first outlet end and a second outlet end at respective sides of the exhaust duct. The exhaust duct includes a first housing including a first body forming an outer wall of the inlet end, and further includes second bodies respectively extending on respective sides from the first body and respectively forming the first outlet end and the second outlet end; a second housing spaced apart from the first body, forming an inner wall of the inlet end, and extending curvedly toward the second bodies; and a connection housing connecting the first housing to the second housing and including at least one recess portion recessed toward the inlet end.

Provided are an exhaust duct, an exhaust duct assembly, and an aircraft using the exhaust duct. The exhaust duct has a structure that enables combustion gas to be diverged and discharged from an inlet end to a first outlet end and a second outlet end at respective sides of the exhaust duct. The exhaust duct includes a first housing including a first body forming an outer wall of the inlet end, and further includes second bodies respectively extending on respective sides from the first body and respectively forming the first outlet end and the second outlet end; a second housing spaced apart from the first body, forming an inner wall of the inlet end, and extending curvedly toward the second bodies; and a connection housing connecting the first housing to the second housing and including at least one recess portion recessed toward the inlet end.

A method for joining two structural elements by welding, in particular by butt welding comprises forming a weld line joining the two structural elements; and adding material across the weld line, thereby forming one or more crack stoppers for limiting crack propagation along the weld line. The one or more crack stoppers each have a limited extension along the weld line as seen in relation to a length of the weld line. A structural system comprising two structural elements joined by the method is disclosed. The method may be applied, e.g., to components of aircraft engines.

A method for joining two structural elements by welding, in particular by butt welding comprises forming a weld line joining the two structural elements; and adding material across the weld line, thereby forming one or more crack stoppers for limiting crack propagation along the weld line. The one or more crack stoppers each have a limited extension along the weld line as seen in relation to a length of the weld line. A structural system comprising two structural elements joined by the method is disclosed. The method may be applied, e.g., to components of aircraft engines.