Abstract: Tail cone apparatus and methods for reducing nozzle surface temperatures of aircraft engines are disclosed. An example apparatus includes a tail cone to be coupled to an aircraft engine. The tail cone includes a central axis, a cone section, and a plurality of fins. The fins are spaced about the central axis and extend outwardly from an outer surface of the cone section.

Abstract: Tail cone apparatus and methods for reducing nozzle surface temperatures of aircraft engines are disclosed. An example apparatus includes a tail cone to be coupled to an aircraft engine. The tail cone includes a central axis, a cone section, and a plurality of fins. The fins are spaced about the central axis and extend outwardly from an outer surface of the cone section.

Abstract: A nozzle effective exit area control system is created with a convergent-divergent nozzle with a divergent portion of the nozzle having a wall at a predetermined angle of at least 12° from the freestream direction. Disturbance generators are located substantially symmetrically oppositely on the wall to induce flow separation from the wall with the predetermined wall angle inducing flow separation to extend upstream from each disturbance generator substantially to a throat of the nozzle pressurizing the wall and reducing the effective area of the jet flow at the nozzle exit.

Abstract: A thrust vectoring system is created with a convergent-divergent nozzle having a total angle no greater than 150 degrees. A divergent portion of the nozzle has a wall at a predetermined angle of at least 12° from the freestream direction. A disturbance generator is located on the wall to induce flow separation from the wall with the predetermined wall angle sufficient for the induced flow separation to extend upstream from disturbance generator substantially to a throat of the nozzle pressurizing the wall and creating a net vector angle in jet flow through the nozzle.

Abstract: A nozzle effective exit area control system is created with a convergent—divergent nozzle with a divergent portion of the nozzle having a wall at a predetermined angle of at least 12° from the freestream direction. Disturbance generators are located substantially symmetrically oppositely on the wall to induce flow separation from the wall with the predetermined wall angle inducing flow separation to extend upstream from each disturbance generator substantially to a throat of the nozzle pressurizing the wall and reducing the effective area of the jet flow at the nozzle exit.

Abstract: A thrust vectoring system is created with a convergent-divergent nozzle having a total angle no greater than 150 degrees. A divergent portion of the nozzle has a wall at a predetermined angle of at least 12° from the freestream direction. A disturbance generator is located on the wall to induce flow separation from the wall with the predetermined wall angle sufficient for the induced flow separation to extend upstream from disturbance generator substantially to a throat of the nozzle pressurizing the wall and creating a net vector angle in jet flow through the nozzle.

Abstract: In one embodiment of the disclosure, a fluid mixing device comprises a flow duct, with a wall having an inner surface defining a fluid flow path for a primary flow, and at least one deployable and retractable projection. The projection is adapted to controllably generate at least one secondary flow adjacent the inner surface. In other embodiments, methods are provided of controllably mixing at least one fluid within a fluid mixing device.

Abstract: In one embodiment of the disclosure, a fluid mixing device comprises a flow duct, with a wall having an inner surface defining a fluid flow path for a primary flow, and at least one deployable and retractable projection. The projection is adapted to controllably generate at least one secondary flow adjacent the inner surface, In other embodiments, methods are provided of controllably mixing at least one fluid within a fluid mixing device.

Abstract: In one embodiment of the disclosure, a fluid mixing device comprises a flow duct, with a wall having an inner surface defining a fluid flow path for a primary flow, and at least one deployable and retractable projection. The projection is adapted to controllably generate at least one secondary flow adjacent the inner surface. In other embodiments, methods are provided of controllably mixing at least one fluid within a fluid mixing device.

Abstract: A nozzle effective exit area control system is created with a convergent-divergent nozzle with a divergent portion of the nozzle having a wall at a predetermined angle of at least 12° from the freestream direction. Disturbance generators are located substantially symmetrically oppositely on the wall to induce flow separation from the wall with the predetermined wall angle inducing flow separation to extend upstream from each disturbance generator substantially to a throat of the nozzle pressurizing the wall and reducing the effective area of the jet flow at the nozzle exit.

Abstract: A variable area flow duct and method. In one embodiment the flow duct includes a plurality of helical vanes arranged around an interior surface wall of the flow duct. The vanes cause secondary flow vortices to be developed in the vicinity of each of the vanes that effectively reduce the interior cross-sectional area of the duct that a primary flow sees as it flows through the duct. In various embodiments fluidic injection is employed to suppress the formation of the secondary flow vortices during certain phases of operation, for example, during an afterburn phase of operation of a jet aircraft engine which the flow duct is being used with. In another embodiment, an ablative coating is used over the vanes to suppress the formation of the secondary flow vortices. The ablative material is removed by the hot fluid flow during an afterburn phase of operation, thus exposing the vanes and enabling the subsequent formation of secondary flow vortices to narrow the cross-sectional area of the throat.

Abstract: In one embodiment of the disclosure, a fluid mixing device comprises a flow duct, with a wall having an inner surface defining a fluid flow path for a primary flow, and at least one deployable and retractable projection. The projection is adapted to controllably generate at least one secondary flow adjacent the inner surface. In other embodiments, methods are provided of controllably mixing at least one fluid within a fluid mixing device.