Abstract: 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.

Abstract: 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.

Abstract: An example method of controlling a flow enhancement device includes providing a flow enhancement device that is configured stabilize a flow of air near a nacelle. The flow enhancement device has a first setting and a second setting that provides more stabilization than the first setting. The method includes monitoring parameters of a turbomachine to determine the stability of the flow of air near the nacelle. The method also adjusts the flow enhancement device between the first setting and the second setting based on the monitoring.

Abstract: A gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, a nacelle assembly that includes an inlet lip section and an inlet internal diffuser section downstream of the inlet lip section. A variable area fan nozzle is positioned near an aft segment of the nacelle assembly, the variable area fan nozzle adaptable to move between a first position having a first discharge airflow area and a second position having a second discharge airflow area greater than the first discharge airflow area. At least one boundary layer control device is positioned near one of the inlet lip section and the inlet internal diffuser section. A controller is configured to move the variable area fan nozzle from the first position to the second position and to actuate the at least one boundary layer control device to introduce an airflow in response to an operability condition.

Abstract: A gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, a nacelle assembly that includes an inlet lip section and an inlet internal diffuser section downstream of the inlet lip section. A variable area fan nozzle is positioned near an aft segment of the nacelle assembly, the variable area fan nozzle adaptable to move between a first position having a first discharge airflow area and a second position having a second discharge airflow area greater than the first discharge airflow area. At least one boundary layer control device is positioned near one of the inlet lip section and the inlet internal diffuser section. A controller is configured to move the variable area fan nozzle from the first position to the second position and to actuate the at least one boundary layer control device to introduce an airflow in response to an operability condition.

Abstract: A method of providing a slim-line nacelle for a gas turbine engine includes the steps of detecting a windmilling condition and increasing a discharge airflow area of a variable area fan nozzle in response to the detection of the windmilling condition.

Abstract: An example method of controlling a flow enhancement device includes providing a flow enhancement device that is configured stabilize a flow of air near a nacelle. The flow enhancement device has a first setting and a second setting that provides more stabilization than the first setting. The method includes monitoring parameters of a turbomachine to determine the stability of the flow of air near the nacelle. The method also adjusts the flow enhancement device between the first setting and the second setting based on the monitoring.

Abstract: A gas turbine engine system includes nacelle, a first boundary layer control device, a second boundary layer control device, at least one sensor, and a controller. The nacelle is defined about an axis and includes an inlet lip section, an inlet internal diffuser section, and a variable area fan nozzle moveable to influence a discharge airflow area of the nacelle. The first boundary layer control device is positioned near the inlet lip section and is actuable to introduce a first airflow at the inlet lip section. The second boundary layer control device is positioned near the inlet internal diffuser section and is actuable to introduce a second airflow at the inlet internal diffuser section. The sensor produces a signal that represents an operability condition.

Abstract: A gas turbine engine system includes a fan and a fan bypass passage downstream of the fan for conveying a bypass airflow from the fan. A nozzle associated with the fan bypass passage includes a plurality of different positions that influence the bypass air flow. One or more sensors near the fan produce a signal representative of a foreign object near the fan. A controller commands the nozzle to move to a desired one of the plurality of different positions in response to the signal from the sensor to change a pressure ratio across the fan to thereby reduce a mechanical stress on the fan.

Abstract: A gas turbine engine system includes nacelle, a first boundary layer control device, a second boundary layer control device, at least one sensor, and a controller. The nacelle is defined about an axis and includes an inlet lip section, an inlet internal diffuser section, and a variable area fan nozzle moveable to influence a discharge airflow area of the nacelle. The first boundary layer control device is positioned near the inlet lip section and is actuable to introduce a first airflow at the inlet lip section. The second boundary layer control device is positioned near the inlet internal diffuser section and is actuable to introduce a second airflow at the inlet internal diffuser section. The sensor produces a signal that represents an operability condition.

Abstract: A method of providing a slim-line nacelle for a gas turbine engine includes the steps of detecting a windmilling condition and increasing a discharge airflow area of a variable area fan nozzle in response to the detection of the windmilling condition.

Abstract: A nacelle assembly for a gas turbine engine includes a nacelle, a variable area fan nozzle, a sensor that detects a windmilling condition and a controller that communicates with the sensor. The variable area fan nozzle is moveable between a first position having a first discharge airflow area and a second position having a second discharge airflow area greater than the first discharge airflow area in response to detecting the windmilling condition.

Abstract: A gas turbine engine system includes a fan (14) and a fan bypass passage (30) downstream of the fan (14) for conveying a bypass airflow from the fan. A nozzle (40) associated with the fan bypass passage (30) includes a plurality of different positions that influence the bypass air flow. One or more sensors (54) near the fan (14) produce a signal representative of a foreign object F near the fan (14). A controller (44) commands the nozzle (40) to move to a desired one of the plurality of different positions in response to the signal from the sensor (54) to change a pressure ratio across the fan (14) to thereby reduce a mechanical stress on the fan (14).

Abstract: A noise control cassette for a gas turbine engine includes a perforated face sheet configured for exposure to an airflow, a non-perforated backing sheet, a core arranged between the face sheet and the backing sheet and defining a cavity between the face sheet and the backing sheet having an effective length tuned so as to provide acoustic reactance control, and an attachment face for attaching the cassette to an airfoil-shaped structure.

Abstract: A noise control cassette for a gas turbine engine includes a perforated face sheet configured for exposure to an airflow, a non-perforated backing sheet, a core arranged between the face sheet and the backing sheet and defining a cavity between the face sheet and the backing sheet having an effective length tuned so as to provide acoustic reactance control, and an attachment face for attaching the cassette to an airfoil-shaped structure.

Abstract: A nacelle assembly for a gas turbine engine includes a nacelle, a variable area fan nozzle, a sensor that detects a windmilling condition and a controller that communicates with the sensor. The variable area fan nozzle is moveable between a first position having a first discharge airflow area and a second position having a second discharge airflow area greater than the first discharge airflow area in response to detecting the windmilling condition.

Abstract: A tangential entry premixing fuel injector (10) for a gas turbine engine combustor includes a pair of offset scrolls (18) whose ends define a pair of entry slots (36) for admitting primary combustion air tangentially into a mixing chamber (28) bounded by the scrolls (18) and by longitudinally spaced endplates (14, 16). An array of fuel injection passages (42) extends along the length of the slots. The passage array is configured to inject a primary fuel nonuniformly along the length of the air entry slots and to control the fuel penetration depth d in proportion to slot height R. The injector also includes a flame disgorging centerbody (48) having a bluff tip (54) longitudinally aligned with the injector's discharge plane (22) and a secondary fuel conduit (80) extending through the centerbody for discharging a secondary combustible fluid, preferably gaseous fuel, through a series of fuel discharge openings (84) in the tip (54).

Abstract: The invention is a tangential entry, premixing fuel injector (10) for the combustion chamber (30) of a turbine engine. The injector includes a pair of arcuate scrolls (18) defining the radially outer boundary of a mixing chamber (28) and a pair of air entry slots (36) for admitting a stream of primary combustion air tangentially into the mixing chamber. The scrolls also include an axially distributed array of primary fuel injection passages (42) for injecting a primary fuel into the primary air stream. A flame stabilizing fuel injector centerbody (46) includes an impingement and transpiration cooled outlet nozzle (50) for introducing secondary fuel and secondary air into the combustion chamber. The nozzle (50) includes an impingement plate(74) with an array of impingement ports (76) and a tip cap (104) with an array of discharge passages (106).

Abstract: A tangential entry premixing fuel injector (10) for a gas turbine engine combustor includes a pair of offset scrolls (18) whose ends define a pair of entry slots (36) for admitting primary combustion air tangentially into a mixing chamber (28) bounded by the scrolls (18) and by longitudinally spaced endplates (14, 16). An array of fuel injection passages (42) extends along the length of the slots. The passage array is configured to inject a primary fuel nonuniformly along the length of the air entry slots and to control the fuel penetration depth d in proportion to slot height H. The injector also includes a flame disgorging centerbody (48) having a bluff tip (54) longitudinally aligned with the injector's discharge plane (22) and a secondary fuel conduit (80) extending through the centerbody for discharging a secondary combustible fluid, preferably gaseous fuel, through a series of fuel discharge openings (84) in the tip (54).

Abstract: An extractive distillation agent used for the distillation of propylene oxide contaminated with water, acetone, acetaldehyde and methanol and consisting essentially of ethylene glycol monomethyl ether is fed to an extractive distillation column within about 2 to about 15 stages from the top of the tower to obtain an overhead distillate fraction consisting of essentially anhydrous propylene oxide contaminated with reduced quantities of acetone, acetaldehyde and methanol, and a heavier bottoms distillation fraction containing substantially all of the ethylene glycol monomethyl ether, water and acetone and some of the methanol introduced into the distillation column.