General Electric Company

Robert Eugene Kraft

William Andrew Bailey

Asif A Syed

William Charles Groll

Robert Paul Czachor

Rolf R Hetico

Horst W Hehmann

Nelson Dirk Gibbens

Paul Michael Smith

Karen B Kontos

James Edward Stoker

Rolf Robert Hetico

An apparatus and method for suppressing dynamic instability in a bleed duct of a gas turbine engine includes a fan bypass duct configured to permit a flow of air through the gas turbine engine. The fan bypass duct defines a fan duct surface, and the bleed duct has an inlet in fluid communication with the fan bypass duct and a flow control valve having an opened position and a closed position. A flow diverter is positioned on the fan duct surface proximate the inlet of the bleed duct and diverts the flow of air from the inlet when the flow control valve is closed, while permitting a portion of the flow of air to enter the inlet when the flow control valve is opened.

Apparatus and method for suppressing dynamic pressure instability in bleed duct

A bleed duct is configured for bleeding fan air from the fan bypass duct in a turbofan aircraft engine. The bleed duct includes a tubular conduit having an inlet and outlet at opposite ends. The conduit is configured in flow area for recovering pressure from speeding fan air bled therethrough. A shroud extends forwardly from the duct inlet for suppressing dynamic pressure oscillations inside the conduit without degrading the pressure recovery.

Shrouded turbofan bleed duct

A method for operating a pulse detonation system. The method includes providing a pulse detonation chamber including a plurality of detonation tubes extending therein, and detonating a mixture of fuel and air within each detonation tube such that at least a first tube is detonated at a different time than at least a second detonation tube.

Methods for operating gas turbine engines

Methods and apparatus for operating gas turbine engines

A fan casing for a gas turbine engine is provided which combines the functions of blade containment and noise suppression. The fan casing has an annular metallic inner shell with a plurality of holes are formed therethrough. An acoustic absorber, such as a cellular resonator, is disposed around the inner shell.

Fan casing acoustic treatment

An acoustic treatment for the air ducts of a gas turbine engine. The acoustic treatment generally includes a facesheet having a plurality of holes therein, a backplate spaced apart from the facesheet, and a plurality of interconnected cells between the facesheet and backplate. Each of the cells is defined by walls attached to the facesheet and the backplate, and at least some of the walls are formed of a porous material so that air is able to flow through the cells in a direction parallel to the facesheet and backplate.

Rigid sandwich panel acoustic treatment

An actively controlled acoustic treatment panel for suppressing noise in a gas turbine engine nacelle including a backsheet formed by a planar matrix of adjacent individually controllable elements, where each of the controllable elements has a transducer and a honeycomb cell enclosing the transducer. A facesheet is also bonded to the controllable elements. A plurality of sensors are positioned within the acoustic treatment panel for sensing acoustic pressure of the noise propagated against the facesheet. A driver is provided for electrically driving each of the transducers to effect displacement thereof in a direction substantially perpendicular to the facesheet. Circuitry is also operatively connected to the pressure sensors and the driver for controlling velocity magnitude and phase of the transducers during displacement, wherein a resulting acoustic impedance at the facesheet achieves a desired acoustic impedance boundary condition at the nacelle. The transducer is further made up of an inner lamination layer, an outer lamination layer, and a piezoelectric membrane positioned between the inner and outer lamination layers, wherein a plurality of aligned openings are provided in the inner and outer lamination layers so that the piezoelectric membrane can be displaced either toward or away from the facesheet.

Actively controlled acoustic treatment panel

An active liner for attenuating noise includes a rigid backplate supporting a piezoelectric panel. A pressure transducer is disposed in the panel for sensing acoustic pressure of noise being propagated against a face surface of the panel. A controller includes a predetermined schedule of acoustic impedance for controlling a displacement driver joined to the panel to effect a displacement velocity of the panel face surface for obtaining a predetermined acoustic impedance at the sensed acoustic pressure for attenuating noise.

Active acoustic liner

A phased treatment noise suppression panel is provided for use in an exhaust duct. The panel consists of individual sections designed with specific modal attenuation characteristics and located axially within the duct in such a sequential order, with respect to the noise source, as to take maximum advantage of modal redistribution effects on overall noise suppression.

Growing community of inventors

Cincinnati, OH, United States of America

Robert Eugene Kraft