Methods and apparatus for reducing flow distortion at engine fans of nacelles are disclosed. An example apparatus for reducing flow distortion at an engine fan of a nacelle includes a plurality of nozzles radially spaced about an inner wall of the nacelle. In some examples, respective ones of the nozzles are positioned to eject corresponding respective jets of fluid adjacent the inner wall in a downstream direction toward the engine fan. The example apparatus further includes a controller to selectively activate the respective ones of the nozzles according to a time-based sequence. In some examples, the time-based sequence corresponds to a directional sequence that moves in an arcuate direction along a circumference of the inner wall.

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 aero damping measurement system is provided. The system includes a shroud defining a tunnel, a hub disposed within the tunnel, and a plurality of blades coupled to the hub. The blades may rotate about the hub. A gas pressure probe may have a tip extending to the tunnel to deliver a pressurized burst into the tunnel. An aeromechanical identification system may include a pressurized gas source, a valve in fluid communication with the pressurized gas source, and the gas pressure probe may be in fluid communication with the valve. The valve may control a flow of a pressurized gas from the pressurized gas source into the gas pressure probe. A pressure sensor may be coupled to the gas pressure probe and configured to measure a pressure within the gas pressure probe.

Methods and apparatus for reducing flow distortion at engine fans of nacelles are disclosed. An example apparatus for reducing flow distortion at an engine fan of a nacelle includes a plurality of nozzles radially spaced about an inner wall of the nacelle. In some examples, respective ones of the nozzles are positioned to eject corresponding respective jets of fluid adjacent the inner wall in a downstream direction toward the engine fan. The example apparatus further includes a controller to selectively activate the respective ones of the nozzles according to a time-based sequence. In some examples, the time-based sequence corresponds to a directional sequence that moves in an arcuate direction along a circumference of the inner wall.

An aero damping measurement system is provided. The system includes a shroud defining a tunnel, a hub disposed within the tunnel, and a plurality of blades coupled to the hub. The blades may rotate about the hub. A gas pressure probe may have a tip extending to the tunnel to deliver a pressurized burst into the tunnel. An aeromechanical identification system may include a pressurized gas source, a valve in fluid communication with the pressurized gas source, and the gas pressure probe may be in fluid communication with the valve. The valve may control a flow of a pressurized gas from the pressurized gas source into the gas pressure probe. A pressure sensor may be coupled to the gas pressure probe and configured to measure a pressure within the gas pressure probe.

A turbine engine including a compressor rotor and a rotating detonation combustion (RDC) system. The compressor rotor includes a compressor airfoil defining a trailing edge disposed within a core flowpath of the turbine engine. The core flowpath defines a radial distance between an outer radius and an inner radius at the compressor rotor. The RDC system includes an outer wall and an inner wall each extended along a lengthwise direction and defining a detonation chamber therebetween. The RDC system further includes a strut defining a nozzle assembly and a fuel injection opening providing a flow of fuel to the detonation chamber. The compressor rotor provides a flow of oxidizer in direct fluid communication to the nozzle assembly of the RDC system.

A method and concept for employing a T-sin-alpha kill vehicle with energy flexibility is disclosed. The energy flexibility method applies divert pulses at multiple phases of the kill vehicle flight time and allows for range extension to increase the kill vehicle coverage of targets outside the normal reach, reaction to target updates, removal of navigation error, and homing divert to intercept the target. Each of these capabilities is essential to the successful intercept of exo-atmospheric ballistic targets in their midcourse phase of flight. A flight vehicle includes a main body, a number of attitude control mechanisms, a control unit, a divert system, a sensor unit, and an attitude control system. The divert system provides acceleration of the flight vehicle in a desired direction. The sensor unit tracks a target along a line of sight (LOS) of the sensor unit. The attitude control system maintains an orientation of the main body.

An object of the present invention is to provide a method and a system for implementing the method so as to alleviate the disadvantages of a reciprocating combustion engine and gas turbine in electric energy production. The invention is based on the idea of arranging a combustion chamber (10) outside a turbine (22) and providing compressed air from serially connected compressors to the combustion chamber in order to carry out a combustion process supplemented with high pressure steam pulses. The combustion chamber (10) is arranged to receive compressed air from each compressing stage of the serially connected compressors (24) for gradually increasing the amount of compressed air in the combustion chamber (10).

A piezo-actuated valve, system, and method of exciting gas turbine turbomachinery are provided. The piezo-actuated valve includes a valve body extending along a first axis between a first and second end, the valve body defining a first opening near the first end, a second opening near the second end, a third opening centrally located on the valve body, and a valve cavity between the first opening and the second opening, a tube connected to the third opening and extending from the valve body along a second axis transverse to the first axis, a shuttle valve assembly slidably disposed within the valve body, wherein the shuttle valve slides between the first end to a first stopper and the second end to a second stopper, a first piezo injector having an injector tip extending through the first opening, and a second piezo injector having an injector tip extending through the second opening.

A system for minimising the formation of ice crystals in the fuel system pipework of a gas turbine engine. The system includes an ultrasonic transmitter located within a wall of a pipe in the fuel system through which fuel passes. The system also includes a controller that causes said ultrasonic transmitter to produce ultrasonic waves when the temperature of the fuel is sufficiently low for any water in the fuel to freeze, the ultrasonic waves being sufficient to break particles of ice contained in the fuel that passes through the pipe. A method of minimising the formation of ice crystals in the fuel system pipework of a gas turbine engine is also disclosed.