A gas turbine engine is disclosed having a tip clearance control system. The tip clearance control system has a cabin blower system, a casing arranged in use about a rotor of a gas turbine engine and a fluid delivery passage. The cabin blower system having a cabin blower compressor arranged in use to compress fluid used in a cabin of an aircraft and to compress fluid conducted via the fluid delivery passage into heat exchange with the casing.

A variable speed pumping system, for an aircraft, comprising: a first electrical machine, the first electrical machine comprising an electrical machine rotor shaft mechanically connected to an engine of the aircraft and electrical machine stator coils; an electric pump motor-generator, the electric pump motor-generator comprising an electric pump rotor shaft mechanically connected to the electrical machine rotor shaft via a one way drive arrangement and electric pump stator coils; wherein the electric pump rotor shaft is mechanically connected to a fluid pumping system.

The present invention provides a multi-stage compressor for a gas turbine engine. The compressor has: a first outer casing, a second outer casing radially outward of the first outer casing, and a first bleed plenum one or more second bleed plenums located between the first and second outer casings and arranged to receive, in use, bleed flows of compressed air from respective stages of the compressor and to send the bleed flows to respective ports in the second outer casing. The first bleed plenum overlaps the, or each, second bleed plenum such that the, or each, second bleed plenum fluidly communicates with its port via a respective duct which, on extending between an off-take from the second bleed plenum to the port, passes through the first bleed plenum. The, or each, duct is configured to accommodate relative movement between the first and second outer casings.

The present invention provides a multi-stage compressor for a gas turbine engine. The compressor has: a first outer casing, a second outer casing radially outward of the first outer casing, and a first bleed plenum one or more second bleed plenums located between the first and second outer casings and arranged to receive, in use, bleed flows of compressed air from respective stages of the compressor and to send the bleed flows to respective ports in the second outer casing. The first bleed plenum overlaps the, or each, second bleed plenum such that the, or each, second bleed plenum fluidly communicates with its port via a respective duct which, on extending between an off-take from the second bleed plenum to the port, passes through the first bleed plenum. The, or each, duct is configured to accommodate relative movement between the first and second outer casings.

A blower assembly for providing air to an airframe system, including a rotor configured to be mechanically coupled to a spool of a gas turbine engine and a flow modifier configured to receive and/or direct flow to the rotor; wherein the blower assembly is configured to permit relative movement between the rotor and the flow modifier to move between: a compressor configuration in which the rotor is configured to be driven to rotate by the spool and to receive and compress air from the gas turbine engine, and discharge the compressed air for supply to the airframe system; and a turbine configuration in which the rotor is configured to receive air from an external air source to drive the spool to rotate.

Exhaust nozzles for outflow valves (OFVs) that are usefully employed in aircraft pressurization systems include an upstream solid (e.g., cylindrical) wall section and a downstream solid exhaust wall section fixed to the upstream solid wall section. The downstream solid exhaust wall section includes a circumferential portion defining a series of air intake perforations. A pair of vortex generators may also be provided upstream of the series of air intake perforations. The air intake perforations and optional vortex generators thereby allow air from the ambient pressure environment to be introduced into the boundary layer of pressurized air discharged by the OFV in the interior of the perforated region of the downstream solid exhaust wall section of the nozzle thereby reducing adverse pressure gradients therewithin which in turn results in a more attached air flow and hence less perceived noise.

A ram air system includes a ram air inlet, a ram air outlet, a conduit fluidly coupling the ram air inlet to the ram air outlet, and a relief port disposed within the conduit. A method of controlling a ram air system includes disposing a relief port within a conduit of the ram air system, wherein the conduit fluidly couples a ram air inlet to a ram air outlet in order to minimize or otherwise reduce drag, and to control unstable airflow that can otherwise cause resonant instability.

A ram air system includes a ram air inlet, a ram air outlet, a conduit fluidly coupling the ram air inlet to the ram air outlet, and a relief port disposed within the conduit. A method of controlling a ram air system includes disposing a relief port within a conduit of the ram air system, wherein the conduit fluidly couples a ram air inlet to a ram air outlet in order to minimize or otherwise reduce drag, and to control unstable airflow that can otherwise cause resonant instability.

An airplane is provided. The airplane includes a pressurized volume and an air conditioning system. The pressurized volume provides a first medium. The air conditioning system includes a heat exchanger and a compressor. The heat exchanger transfers heat from a second medium to the first medium. The compressor receives the second medium. The compressor is upstream of the heat exchanger in a flow path of the second medium.

An airplane is provided. The airplane includes a pressurized volume and an air conditioning system. The pressurized volume provides a first medium. The air conditioning system includes a heat exchanger and a compressor. The heat exchanger transfers heat from a second medium to the first medium. The compressor receives the second medium. The compressor is upstream of the heat exchanger in a flow path of the second medium.