Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A mattress is formed with an upper variable firmness section covering a lower section of generally uniform firmness. The upper section is divided along its length into four transversely extending regions, namely, a head, an upper torso, a lower torso and a leg support region. The lengths of the regions approximate the average lengths of a preselected range of corresponding human body parts. Thus, the head support region approximates the length of a head and neck; the upper torso region approximates the length of the torso from the neck to the waist; the lower torso region approximates the length from the waist to the crotch; and the leg support region approximates the length of the legs from the crotch to the feet bottoms. Each region is of a substantially uniform firmness, but the firmness is varied from one region to another. Thus, the upper torso region is the firmest region; the head and lower torso regions are about of the same firmnesses and the leg support region is the least firm.

Abstract: A mattress is formed with an upper variable firmness section covering a lower section of generally uniform firmness. The upper section is divided along its length into four transversely extending regions, namely, a head, an upper torso, a lower torso and a leg support region. The lengths of the regions approximate the average lengths of a preselected range of corresponding human body parts. Thus, the head support region approximates the length of a head and neck; the upper torso region approximates the length of the torso from the neck to the waist; the lower torso region approximates the length from the waist to the crotch; and the leg support region approximates the length of the legs from the crotch to the feet bottoms. Each region is of a substantially uniform firmness, but the firmness is varied from one region to another. Thus, the upper torso region is the firmest region; the head and lower torso regions are about of the same firmnesses and the leg support region is the least firm.

Abstract: A standard size mattress is formed with four longitudinally arranged regions, i.e., a head, an upper torso, a lower torso and a leg support region, for supporting a person comfortably and substantially level. The length of the head support region is equal to the approximate height of a person's head and neck. The length of the combined torso support regions is equal to the approximate height of a person's torso from the crotch to the juncture with the neck, with the upper torso region being roughly two-thirds and the lower torso region being roughly one-third of the length of the combined torso support regions. The length of the leg portion is equal to approximately the height of the legs from the crotch to the bottom of the feet. Thus, the lengths of the four regions are roughly in the ranges of 18%, 23%, 14% and 45%, respectively, of the length of a typical standard mattress.