New exemplary heat exchange configurations that incorporate internal or external surfaces equipped with perturbators, for changing the thermal behavior of the system, or for modulating the surface temperature distribution of the flow surfaces. This is achieved by applying an acoustic wave to the fluid flow in a heat exchange passage, and selecting the frequency of the acoustic exciting wave to be the same as the acoustic resonance frequency of the heat exchange passage itself. As the traveling waves interact with the boundaries confining the heat exchange passages, constructive interference of the incident and reflected waves give rise to a standing wave. Thus, the heat exchange passages act as a resonator, and by superimposing this standing wave on the separating and reattaching fluid flow, significant heat transfer improvement can be achieved. This is accomplished without the need to significantly increase the pressure required to achieve the desired through flow.

An engine assembly includes a nacelle configured to at least partially surround an engine and a thrust reverser coupled to the nacelle. The thrust reverser includes: a thrust-reversing element movable relative to the nacelle between a stowed position and a deployed position; a hydraulic actuator operably coupled to move the thrust-reversing element; and a fluid control system configured to operate the hydraulic actuator. The fluid control system includes: a directional control unit including a directional control valve operable to selectively route fluid between a pressurized fluid source, the actuator, and a fluid return reservoir; one or more bypass fluid lines providing fluid communication between the actuator and the fluid return reservoir independent of the directional control valve; and a flow limiter residing between the pressurized fluid source and the directional control valve, the flow limiter configured to inhibit a pressure draw by the actuator from surpassing a predetermined threshold.

New exemplary heat exchange configurations that incorporate internal or external surfaces equipped with perturbators, for changing the thermal behavior of the system, or for modulating the surface temperature distribution of the flow surfaces. This is achieved by applying an acoustic wave to the fluid flow in a heat exchange passage, and selecting the frequency of the acoustic exciting wave to be the same as the acoustic resonance frequency of the heat exchange passage itself. As the traveling waves interact with the boundaries confining the heat exchange passages, constructive interference of the incident and reflected waves give rise to a standing wave. Thus, the heat exchange passages act as a resonator, and by superimposing this standing wave on the separating and reattaching fluid flow, significant heat transfer improvement can be achieved. This is accomplished without the need to significantly increase the pressure required to achieve the desired through flow.

New exemplary heat exchange configurations that incorporate internal or external surfaces equipped with perturbators, for changing the thermal behavior of the system, or for modulating the surface temperature distribution of the flow surfaces. This is achieved by applying an acoustic wave to the fluid flow in a heat exchange passage, and selecting the frequency of the acoustic exciting wave to be the same as the acoustic resonance frequency of the heat exchange passage itself. As the traveling waves interact with the boundaries confining the heat exchange passages, constructive interference of the incident and reflected waves give rise to a standing wave. Thus, the heat exchange passages act as a resonator, and by superimposing this standing wave on the separating and reattaching fluid flow, significant heat transfer improvement can be achieved. This is accomplished without the need to significantly increase the pressure required to achieve the desired through flow.

A propulsion system coupled to a vehicle. The system includes a diffusing structure and a conduit portion configured to introduce to the diffusing structure through a passage a primary fluid produced by the vehicle. The passage is defined by a wall, and the diffusing structure comprises a terminal end configured to provide egress from the system for the introduced primary fluid. A constricting element is disposed adjacent the wall. An actuating apparatus is coupled to the constricting element and is configured to urge the constricting element toward the wall, thereby reducing the cross-sectional area of the passage.

An engine assembly includes a nacelle configured to at least partially surround an engine and a thrust reverser coupled to the nacelle. The thrust reverser includes: a thrust-reversing element movable relative to the nacelle between a stowed position and a deployed position; a hydraulic actuator operably coupled to move the thrust-reversing element; and a fluid control system configured to operate the hydraulic actuator. The fluid control system includes: a directional control unit including a directional control valve operable to selectively route fluid between a pressurized fluid source, the actuator, and a fluid return reservoir; one or more bypass fluid lines providing fluid communication between the actuator and the fluid return reservoir independent of the directional control valve; and a flow limiter residing between the pressurized fluid source and the directional control valve, the flow limiter configured to inhibit a pressure draw by the actuator from surpassing a predetermined threshold.

The present disclosure provides systems and apparatuses for use in turbine systems that integrate structural frame elements into a variable-vectoring flow control configuration in order to reduce the weight and length of such turbine systems. In one exemplary embodiment, an apparatus for directing a gas flow includes an annular outer structural casing, an annular central hub disposed within the outer structural casing, and a plurality of structural support elements extending radially between the central hub and the outer structural casing. The apparatus further includes a plurality of positionally-fixed, variable-vectoring flow control bodies extending radially between the central hub and the outer structural casing and positioned circumferentially along the central hub between ones of the plurality of structural support elements.

An engine assembly includes a nacelle configured to at least partially surround an engine and a thrust reverser coupled to the nacelle. The thrust reverser includes: a thrust-reversing element movable relative to the nacelle between a stowed position and a deployed position; a hydraulic actuator operably coupled to move the thrust-reversing element; and a fluid control system configured to operate the hydraulic actuator. The fluid control system includes: a directional control unit including a directional control valve operable to selectively route fluid between a pressurized fluid source, the actuator, and a fluid return reservoir; one or more bypass fluid lines providing fluid communication between the actuator and the fluid return reservoir independent of the directional control valve; and a flow limiter residing between the pressurized fluid source and the directional control valve, the flow limiter configured to inhibit a pressure draw by the actuator from surpassing a predetermined threshold.

The present disclosure provides systems and apparatuses for use in turbine systems that integrate structural frame elements into a variable-vectoring flow control configuration in order to reduce the weight and length of such turbine systems. In one exemplary embodiment, an apparatus for directing a gas flow includes an annular outer structural casing, an annular central hub disposed within the outer structural casing, and a plurality of structural support elements extending radially between the central hub and the outer structural casing. The apparatus further includes a plurality of positionally-fixed, variable-vectoring flow control bodies extending radially between the central hub and the outer structural casing and positioned circumferentially along the central hub between ones of the plurality of structural support elements.

New exemplary heat exchange configurations that incorporate internal or external surfaces equipped with perturbators, for changing the thermal behavior of the system, or for modulating the surface temperature distribution of the flow surfaces. This is achieved by applying an acoustic wave to the fluid flow in a heat exchange passage, and selecting the frequency of the acoustic exciting wave to be the same as the acoustic resonance frequency of the heat exchange passage itself. As the traveling waves interact with the boundaries confining the heat exchange passages, constructive interference of the incident and reflected waves give rise to a standing wave. Thus, the heat exchange passages act as a resonator, and by superimposing this standing wave on the separating and reattaching fluid flow, significant heat transfer improvement can be achieved. This is accomplished without the need to significantly increase the pressure required to achieve the desired through flow.