Abstract: A gas turbine engine has a core engine including: a compressor, combustion equipment which receives compressed air from the compressor, a circumferential row of nozzle guide vanes, and a turbine. The nozzle guide vanes defines a throat receiving hot working gases from the combustion equipment into the turbine. The gas turbine engine further has an air system which is switchably operable between an on-position which opens a diversion pathway along which a portion of the compressed air exiting the compressor bypasses the combustion equipment to join the hot working gases at re-entry holes located between the nozzle guide vanes and a rotor at the front of the turbine, thereby increasing the semi-dimensional mass flow ?(T30)0.5/(P30) of the core engine at the exit of the compressor, and an off-position which closes the diversion pathway, thereby decreasing the semi-dimensional mass flow of the core engine at the exit of the compressor.

Abstract: A gas turbine engine includes a turbine and a turbine cooling arrangement. The turbine includes a turbine rotor surrounded by a static rotor track liner, and a nozzle guide vane downstream of the rotor in a core main gas flow path. The cooling arrangement includes a first air duct that provides cooling airflow to a rotor track liner cooling plenum and a second air duct that provides a cooling airflow to the nozzle guide vane. A common manifold is upstream in the cooling airflow of the ducts and provides cooling air to the ducts. A two-way valve modulates air provided to the ducts from the manifold. The valve is operates in a first or second mode. In the first mode, air flow to the first duct is relatively high and airflow to the second duct is relatively low compared to where the valve is operated in the second mode.

Abstract: A gas turbine engine has a core engine including: a compressor, combustion equipment which receives compressed air from the compressor, a circumferential row of nozzle guide vanes, and a turbine. The nozzle guide vanes defines a throat receiving hot working gases from the combustion equipment into the turbine. The gas turbine engine further has an air system which is switchably operable between an on-position which opens a diversion pathway along which a portion of the compressed air exiting the compressor bypasses the combustion equipment to join the hot working gases at re-entry holes located between the nozzle guide vanes and a rotor at the front of the turbine, thereby increasing the semi-dimensional mass flow ?(T30)0.5/(P30) of the core engine at the exit of the compressor, and an off-position which closes the diversion pathway, thereby decreasing the semi-dimensional mass flow of the core engine at the exit of the compressor.

Abstract: A gas turbine engine includes a turbine and a turbine cooling arrangement. The turbine includes a turbine rotor surrounded by a static rotor track liner, and a nozzle guide vane downstream of the rotor in a core main gas flow path. The cooling arrangement includes a first air duct that provides cooling airflow to a rotor track liner cooling plenum and a second air duct that provides a cooling airflow to the nozzle guide vane. A common manifold is upstream in the cooling airflow of the ducts and provides cooling air to the ducts. A two-way valve modulates air provided to the ducts from the manifold. The valve is operates in a first or second mode. In the first mode, air flow to the first duct is relatively high and airflow to the second duct is relatively low compared to where the valve is operated in the second mode.

Abstract: The present disclosure relates to a vortex reducer (100) for a bleed flow (104) in an axial turbomachine comprising a rotor disc (113). The vortex reducer may comprise one or more guide channels (122) arrangeable adjacent to a first side (113a) of the rotor disc to at least partially de-swirl the bleed flow. The vortex reducer may further comprise a passage (130) connecting the first side of the rotor disc to a high pressure flow source capable of providing flow (134) to the first side of the rotor disc to mix with the bleed flow on the first side of the rotor disc.

Abstract: A gas turbine engine has in flow series a compressor section, a combustor, and a turbine section. The engine includes a turbine section rotor disc, and a stationary wall forward of a front face or rearward of a rear face of the rotor disc. The wall defines a cavity between the stationary wall and the rotor disc, and has a plurality of air entry nozzles through which cooling air can be delivered into the cavity at an inlet swirl angle. The engine further includes a cooling air supply arrangement which accepts a flow of compressed air and supplies the compressed air to the nozzles for delivery into the cavity. The cooling air supply arrangement and the nozzles are configured such that the inlet swirl angle of the air delivered into the cavity can be varied between a first inlet swirl angle and a second inlet swirl angle.

Abstract: The present disclosure relates to a vortex reducer (100) for a bleed flow (104) in an axial turbomachine comprising a rotor disc (113). The vortex reducer may comprise one or more guide channels (122) arrangeable adjacent to a first side (113a) of the rotor disc to at least partially de-swirl the bleed flow. The vortex reducer may further comprise a passage (130) connecting the first side of the rotor disc to a high pressure flow source capable of providing flow (134) to the first side of the rotor disc to mix with the bleed flow on the first side of the rotor disc.

Abstract: A gas turbine engine has in flow series a compressor section, a combustor, and a turbine section. The engine includes a turbine section rotor disc, and a stationary wall forward of a front face or rearward of a rear face of the rotor disc. The wall defines a cavity between the stationary wall and the rotor disc, and has a plurality of air entry nozzles through which cooling air can be delivered into the cavity at an inlet swirl angle. The engine further includes a cooling air supply arrangement which accepts a flow of compressed air and supplies the compressed air to the nozzles for delivery into the cavity. The cooling air supply arrangement and the nozzles are configured such that the inlet swirl angle of the air delivered into the cavity can be varied between a first inlet swirl angle and a second inlet swirl angle.

Abstract: Provision of flow control arrangements which can be switched from high flow restriction to low flow restriction or vice versa are desirable. It is known to use switched vortex valves comprising a vortex chamber having a diverter portion which jets a through flow into either radial presentation to an outlet or tangential presentation with differential flow restrictions. Typically deflection is through cross flows presented from control ports as determined by mechanically actuated and controlled valves. Sensors are required to determine pressure differentials in order to actuate these moving part valves. By providing association between the control ports and an outlet path along with appropriate configuration and sizing of the flow regulators switching states can be provided through the cross flows presented via the flow regulators between the high and low through flow restriction. The flow regulators generally comprise orifice restrictors, diffusers/venturi arrangements or vortex throttles.

Abstract: A rotor assembly for a gas turbine engine, the rotor assembly comprises at least two rotors defining a cavity therebetween. A first rotor defines a cooling air inlet in its radially inward portion. A second rotor defines a cooling air outlet in its radially outward portion, such that the cooling air passes radially outwardly through the cavity.

Abstract: A flow control system comprises includes a fluidic control device having a main fluid path for a flow of fluid through the device, and a control fluid path for a control flow of fluid through the device. At least part of the control fluid path coincides with at least part of the main fluid path to control the flow of fluid out of the fluidic control device. A valve is associated with the control fluid path. The valve is movable between an open condition to allow fluid to flow along the control fluid path to effect the aforesaid control of the fluid flow out of the fluidic control device, and a closed condition to inhibit or prevent fluid flow along the control fluid path.

Abstract: Provision of flow control arrangements which can be switched from high flow restriction to low flow restriction or vice versa are desirable. It is known to use switched vortex valves comprising a vortex chamber having a diverter portion which jets a through flow into either radial presentation to an outlet or tangential presentation with differential flow restrictions. Typically deflection is through cross flows presented from control ports as determined by mechanically actuated and controlled valves. Sensors are required to determine pressure differentials in order to actuate these moving part valves. By providing association between the control ports and an outlet path along with appropriate configuration and sizing of the flow regulators switching states can be provided through the cross flows presented via the flow regulators between the high and low through flow restriction. The flow regulators generally comprise orifice restrictors, diffusers/venturi arrangements or vortex throttles.

Abstract: Loss reduction apparatus for a fluid transfer system includes a fluid device. The fluid device defines a first fluid path along which a greater part of a fluid flows in a first condition, and a second fluid path along which a greater part of the fluid flows in a second condition. The apparatus is arranged so that when a leak occurs at a location in the system, the leak causes a relative reduction in fluid pressure at the location, which moves the device from the first condition to the second condition.

Abstract: A rotor assembly for a gas turbine engine, the rotor assembly comprises at least two rotors defining a cavity therebetween. A first rotor defines a cooling air inlet in its radially inward portion. A second rotor defines a cooling air outlet in its radially outward portion, such that the cooling air passes radially outwardly through the cavity.