Abstract: This invention concerns a system for cooling components in a gas turbine engine, the gas turbine engine including a compressor for driving a primary gas flow to a combustor and a turbine arranged to be driven by combustion gases from the combustor, wherein the system includes: an annular cooling flow passage arranged for fluid communication between the compressor and the turbine, the flow passage having a first inlet arranged to receive gas from the primary gas flow downstream of compressor, and a second inlet located upstream of the first inlet, wherein the annular cooling flow passage has at least one internal wall for guiding airflow from the first inlet towards the airflow from the second inlet, the airflow from the first and second inlets coalesce within the annular flow passage prior to passing along the passage in a direction from the compressor to the turbine.

Abstract: A clearance control device including a segment having a passage to deliver fluid towards a component rotating past the segment. Also a fluid flow device having a first fluid path coupled to the passage and a second fluid path that is decoupled from the passage. A first plasma generator is located in the fluid flow device that directs fluid towards the first fluid path; a second plasma generator is located in the fluid flow device that directs fluid towards the second fluid path; and a control arrangement is configured to alternately energize the first and second plasma generators at an energizing frequency to deliver fluid to the passage at a frequency coincident with the passing frequency of the component.

Abstract: A fuel system for a gas turbine engine, the gas turbine engine including a combustor having a pilot fuel injector and a main fuel injector, the fuel system including first and second variable flow fuel pumps configured to provide metered fuel flow to the pilot injector, and the main injector respectively; first and second variable speed electric motors configured to drive respective first and second fuel pumps; wherein each of the electric motors includes a polyphase motor including a stator having concentrated windings.

Abstract: This invention concerns a system for cooling components in a gas turbine engine, the gas turbine engine including a compressor for driving a primary gas flow to a combustor and a turbine arranged to be driven by combustion gases from the combustor, wherein the system includes: an annular cooling flow passage arranged for fluid communication between the compressor and the turbine, the flow passage having a first inlet arranged to receive gas from the primary gas flow downstream of compressor, and a second inlet located upstream of the first inlet, wherein the annular cooling flow passage has at least one internal wall for guiding airflow from the first inlet towards the airflow from the second inlet, the airflow from the first and second inlets coalesce within the annular flow passage prior to passing along the passage in a direction from the compressor to the turbine.

Abstract: A clearance control device including a segment having a passage to deliver fluid towards a component rotating past the segment. Also a fluid flow device having a first fluid path coupled to the passage and a second fluid path that is decoupled from the passage. A first plasma generator is located in the fluid flow device that directs fluid towards the first fluid path; a second plasma generator is located in the fluid flow device that directs fluid towards the second fluid path; and a control arrangement is configured to alternately energise the first and second plasma generators at an energising frequency to deliver fluid to the passage at a frequency coincident with the passing frequency of the component.

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: It is known there is ingestion of hot gas flow 35 from an annular flow 36 in gas turbine engines. This flow 35 is prevented from attaching to the disc by coolant flow 32 passing through gaps in lock plates 28, 29 by creation of a barrier layer. In order to regulate and enhance this effect spacer protrusions 31 are provided between ends of lock plates 28, 29. In such circumstances the gap 30 is controlled and therefore the rate of leakage flow 32 regulated for best cooling effect. This cooling effect and cooling flow 32 can be further enhanced by providing chutes 39 for presentation of the coolant flow 32.

Abstract: A seal arrangement 32 between a turbine shroud seal segments 38,40 in a gas turbine engine. The arrangement 32 comprises facing slots 34, 36 provided respectively in the segments 38,40 with offset spaces 42, 44 provided between the segments 38,40. A strip 46 is cemented into the slot 36 such that the flow path 50 passes through the space 42, around the free end of the strip 46, and out through the offset space 44, thereby providing a longer flow path.