A fluid system of an aircraft engine includes a first and second fluid conduits. The first conduit fluid conduit fluidly connects to the aircraft engine. A pump fluidly connects to the first fluid conduit and moves therethrough a fluid imparting an excitation frequency to the fluid. The second fluid conduit fluidly connects to the first fluid conduit and to a pressure sensor. A weight is disposed in the second fluid conduit and movable between a first and second positions. A mass of the weight and a liquid capacitance of the second fluid conduit between the second position and a second end of the second fluid conduit define a resonance frequency that is less than the excitation frequency. Fluid pressure monitoring and pressure noise filter construction methods are also disclosed.

A gas turbine engine includes an airfoil and a deicing system. The airfoil radially extends from a hub towards a case disposed about a central longitudinal axis of the gas turbine engine. The deicing system includes an acoustic driver assembly arranged to apply acoustic energy to the airfoil to excite a predetermined vibratory mode of the airfoil.

An active device for attenuating the acoustic emissions of an aircraft turbojet engine includes circulation conduits for a pressurized air flow rate supplying rotary elements each having a pulsation system for the delivered air. The rotary elements are controlled in amplitude and phase and deliver, to outlet diffusers, a pulsed air flow rate with a pulsation at the frequency of the noise to be attenuated having an amplitude and a phase adjusted according to a local feedback law with microphones to attenuate the radiated acoustic power.

A non-transitory computer readable medium with instructions stored thereon, the instructions executable by one or more processors for selecting infrequent or frequent autotuning of a combustor; and determining the health of a combustor. Also, a method of monitoring a combustor within a gas turbine engine system, comprising providing a gas turbine engine system, wherein the gas turbine engine includes an autotuning system; selecting infrequent or frequent autotuning of the combustor; and determining the health of the combustor; wherein said determining the health of a combustor comprises receiving real-time fuel gas temperature data from at least one thermocouple.

A gas turbine engine comprises a fan rotor having fan blades received within an outer nacelle, and the outer nacelle having an inner surface. The outer nacelle is secured to an inner portion through a mount flange at a first axial location. An acoustic treatment extends inwardly of the outer portion of the nacelle and across the axial location of the mount flange and further inwardly toward the fan blades.

An aircraft propulsion unit including two distinct fan spools, and including a first duct and a second duct extending downstream of the two fan spools, the propulsion unit including a control ring disposed on one of the ducts, downstream of one of the fan spools, with at least one annular internal wall extending in an interior space of the duct, the control unit of the control ring being configured to modify the shape of the internal wall, and to cause an air passage cross section in the duct to vary at the ring, a device for acquiring acoustic signals generated by acoustic waves propagating downstream of the fan spools, and a device for processing the acoustic signals, configured to measure a dephasing between the acoustic waves and to control the control ring depending on the dephasing.

According to one embodiment, a system for reducing interference noise of rotor and stator blades includes rotor blades, stator blades, loudspeakers, one or more reference microphones, and a controller. The rotor blades rotate about a central axis. The loudspeakers are discretely arranged on a circle that has a center positioned on the central axis. Each loudspeaker generates a control sound. The controller causes the loudspeakers to generate control sounds of a same phase and a same amplitude. The control sounds correspond to the loudspeakers. The r is selected based on a preset attenuation level concerning the interference noise, and the k, where a is a length of the rotor blades, b is a radius of the circle, r =a/b, k is an upper limit wavenumber.

A system and method for blade health inspection is provided. The system may include a health monitoring processor, an excitation actuator, and a health monitoring sensor. The excitation actuator may pulse a force against an engine blade to cause non-integral vibratory excitations in engine blades. The health monitoring sensor may measure the vibratory excitations. The health monitoring processor may analyze the vibratory excitations to determine the health of the engine blade.

A vibration detection device for detecting vibration of a cartridge including a bearing housing that accommodates a rotor coupling a wheel and a rotor shaft, and a bearing rotatably supporting the rotor, the bearing housing including a lubricant-oil passage port for allowing lubricant oil to pass through an interior of the bearing housing, includes: a sensor mount attached to an oil-flow-passage forming member configured to be capable of connecting to and separating from the bearing housing, the oil-flow-passage forming member including, inside thereof, an oil flow passage through which one of lubricant oil to be supplied to the interior of the bearing housing via the lubricant-oil passage port or lubricant oil discharged from the interior of the bearing housing via the lubricant-oil passage port flows; a vibration sensor disposed on the sensor mount; and a vibration transmission leg portion connected to the sensor mount and configured to be in contact with the bearing housing in a state where the oil-flow-passage forming member is connected to the bearing housing.

A section for a gas turbine engine includes a rotating structure, a stationary structure, and a flow guide assembly arranged generally between the rotating structure and the stationary structure. A flow path is defined between the flow guide assembly and one of the rotating structure and the stationary structure. The flow guide assembly includes a plurality of apertures configured to disrupt acoustic waves of air in the flow path. A seal is configured to establish a sealing relationship between the rotating structure and the stationary structure, and wherein an inlet to the flow path is adjacent the seal. A gas turbine engine and a method of disrupting acoustic waves in a flow path of a gas turbine engine are also disclosed.