Pratt-whitney Canada Corp

Sid-Ali Meslioui

Ninad Joshi

Man-Chun Tse

Tahereh Mirmohammadi Ghoojdi

Tony Yee

François Richard

Li-Jen Chen

Richard Francois

A turbo-compounded engine includes a piston engine connected to drive a propulsor. An outlet of the piston engine is operable to connect products of combustion from the piston engine to pass over a turbine. The turbine is connected to drive a turbine shaft also connected to drive the propulsor. An outlet of the turbine is connected into an exhaust duct configured to exhaust the products of combustion. The exhaust duct is provided with an exhaust duct outer wall defining an exhaust chamber. A further cooling air outer wall is positioned outwardly of the exhaust duct. Flow dividers are received within an exhaust chamber inward of the exhaust duct outer wall. The exhaust duct outer wall has an inner surface and the flow dividers have an outer surface. Acoustic treatment is provided on both the inner surface of the exhaust duct outer wall and the outer surface of the flow dividers.

Turbo-compounded engine with exhaust duct acoustic arrangement

An acoustic system is provided that includes a face skin, a back skin and a cellular core arranged between the face skin and the back skin. The face skin includes a first member, a second member and a plurality of ports extending through the face skin. The first member includes a plurality of first perforations. The second member includes a plurality of second perforations and is configured to move along the first member. Each of the ports includes a respective one of the first perforations and a respective one of the second perforations. The cellular core includes a plurality of chambers. Each of the chambers extends between the face skin and the back skin. Each of the chambers is fluidly coupled with a respective one or more of the ports.

Acoustic panel with active impedance control

A turbo-compounded engine includes a piston engine connected to drive a propulsor. An outlet of the piston engine is operable to connect products of combustion from the piston engine to pass over a turbine. The turbine is connected to drive a turbine shaft also providing rotation to the propulsor. An outlet of the turbine is connected into an exhaust duct configured to exhaust the products of combustion. The exhaust duct is provided with an exhaust duct outer wall defining an exhaust chamber, and a further cooling air outer wall is positioned outwardly of the exhaust duct. Struts connect a cooling chamber between the cooling air outer wall and the exhaust duct outer wall into a center bullet. The center bullet has a downstream end for directing the cooling air into the exhaust chamber at a location upstream of a downstream end of the exhaust duct outer wall.

Cooling flow injection to alter exhaust boundary conditions in a turbo-compounded engine

Sandwich-structured noise-attenuating and/or structural panels and methods of manufacturing such panels using ultrasonic welding are described. The method includes: receiving a backing member, a sheet and a cellular structure; assembling the cellular structure between the backing member and the sheet; and ultrasonically welding the backing member and the sheet together.

Sandwich-structured panels and method of manufacture

A gas turbine engine includes a bypass duct extending about a longitudinal centerline of the gas turbine engine. The bypass duct includes at least one bypass duct wall defining at least a portion of a bypass flow path through the bypass duct. The at least one bypass duct wall includes a scoop extending into the bypass flow path. The gas turbine engine further includes a bleed conduit including an inlet connected to the bypass duct within the scoop of the at least one bypass duct wall and at least one louver mounted to the bleed conduit within the inlet. The at least one louver extends between a leading edge and a trailing edge opposite the leading edge. The leading edge is located within the bypass flow path and the trailing edge is located within the bleed conduit.

Fluid control device for fluid bleed system

A multi-engine aircraft includes first and second gas turbine engines for providing motive power to the aircraft, each of the first and second engines comprising an air system, an air pressure line extending between and fluidly connecting the air systems of the first and second engines, and a pressure wave damper communicating with the air pressure line extending between the first and second engines.

Air system of multi-engine aircraft

A method for controlling noise emitted by a hybrid-electric gas turbine engine for an aircraft during a takeoff flight condition includes applying a first total rotational force to a shaft with a turbine and an electric motor. The first total rotational force includes a first electric rotational force applied by the electric motor and a first thermal rotational force applied by the turbine. The first total rotational force has a first rotational force ratio of the first electric rotational force to the first thermal rotational force. The method further includes controlling the noise emitted by the gas turbine engine by reducing the first rotational force ratio from an initial rotational force ratio of the rotational force ratio as an altitude of the aircraft increases and maintaining the first total rotational force substantially constant while reducing the rotational force ratio.

Systems and methods for controlling noise in aircraft powered by hybrid-electric gas turbine engines

There is provided a turbofan engine having: a fan rotatable about an axis within a case; a first acoustic treatment lining a first portion of the case upstream of the fan; and a second acoustic treatment lining a second portion of the case downstream of the fan, the first acoustic treatment having different noise-attenuating characteristics relative to the second acoustic treatment.

Turbofan engine with acoustic treatment

A system has: a combustor; a plenum surrounding the combustor; a transfer tube having an inlet fluidly connected to the plenum and at least two outlets, a first flow passageway defined between the inlet and a first outlet, a second flow passageway defined between the inlet and a second outlet, the second flow passageway connected to a discharge region outside of the plenum; a flow valve disposed within the second flow passageway and operable between an open position and a closed position, in the open position the flow valve fluidly connects the plenum with the discharge region, in the closed position the flow valve blocking fluid communication between the plenum and the discharge region; and a controller communicatively coupled to the flow valve to control operation thereof by: causing the flow valve to open for a time period; and subsequent to the time period, causing the flow valve to close.

Method and system for operating a gas turbine engine

A method for operating a gas turbine engine comprises providing fuel flow and compressed airflow to a combustor with a fuel-to-air ratio, the compressed airflow being from a compressed air source; detecting at least one parameter indicative of the fuel-to-air ratio being below a predetermined value; and bleeding compressed air from the compressed air source when the at least one parameter indicative of the fuel-to-air ratio is below the predetermined value to increase the fuel-to-air ratio to at least the predetermined value.

An aircraft component and an associated method of manufacturing such aircraft component are disclosed. The aircraft component comprises a backing member, a porous sheet spaced apart from the backing member, and a cellular structure disposed between the backing member and the porous sheet. The cellular structure is attached to at least one of the backing member and the porous sheet by one or more non-adhesive connections.

Aircraft component and method of manufacture

The gas turbine engine includes a fluid system fluidly connecting at least two components of the gas turbine engine, and a tunable resonator in fluid flow communication with the fluid system. The tunable resonator has a resonating volume that varies as a function of a volume of an inflatable member located inside the tunable resonator. The inflatable member having a means for varying the volume of the inflatable member, to thereby tune the resonating volume to a selected frequency of pressure fluctuations or acoustic waves within the fluid system.

Tunable resonator

A bleed air system is disclosed for a turbofan engine having a bypass duct. The bleed air system includes a bleed air conduit having an inlet end connected to the bypass duct and a bleed air flow control valve disposed downstream of the inlet end, and a louver assembly disposed within the opening at inlet end of the bleed air conduit. The louver assembly includes an airfoil-shaped louver blade which extends across the opening in a direction transverse to the flow direction within the bypass duct. A reinforcing rib is attached to the louver blade and extends across the louver assembly in a direction generally parallel to the flow direction.

Bypass duct louver for noise mitigation

Herein provided are methods and systems for reducing an acoustic signature of a gas turbine engine. An acceleration command for the engine is received. In response to receiving the acceleration command: a fuel flow to the engine is increased for a first predetermined time period; subsequent to the first predetermined time period, the fuel flow to the engine is reduced for a second predetermined time period; and subsequent to the second predetermined time period, the fuel flow to the engine is increased for a third time period.

Reducing an acoustic signature of a gas turbine engine

The gas turbine has a plurality of inlet guide vanes each having a blade having a leading edge, a trailing edge, a span extending along the leading edge, and pivot members at opposite ends of the leading edge, and being pivotally mounted across the radial-to-axial intake via the pivot members, the pivot axis extending axially across a radial portion of the radial-to-axial intake. The plurality of inlet guide vanes include a plurality of first inlet guide vanes, and a plurality of second inlet guide vanes, the second inlet guide vanes having a trailing edge recess differing from the corresponding portion of the first inlet guide vanes. During operation, when the inlet guide vanes are pivoted past a given angle toward the tangential orientation, a radial flow of gas is allowed through the trailing edge recesses to avoid or impede vortex whistle.

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Brossard, Canada

Sid-Ali Meslioui