Rolls-Royce plc

There is disclosed an exhaust nozzle 30 for a gas turbine engine, comprising an exhaust structure 32 and a flap 34 configured to bound a passageway 36 through the exhaust structure. The flap 34 is coupled to the exhaust structure in a linkage arrangement configured to move the flap by compound translation and rotation with a single degree of freedom between a first orientation corresponding to a maximum throat area of the passageway and a second orientation corresponding to a minimum throat area of the passageway.

There is provided a method of monitoring the health of an asset. The method comprises obtaining a measured value of an input parameter representing an operational state of the asset, determining, based on the value, a residual that represents the behaviour of the asset, providing the determined residual to an encoder model to map the determined residual to a data point in a feature space, determining a distance of the data point relative to a cluster of data points in the feature space, wherein the cluster of data points are determined by the encoder based on residuals representing nominally healthy assets, and in response to the determined distance exceeding a predetermined distance threshold, generating an abnormal asset behaviour prediction.

There is provided a method of monitoring the health of an asset. The method comprises providing an input representing the behaviour of the asset to an encoder model to map the input to a data point in a feature space, wherein the encoder model is configured to cause data points relating to measured values of input parameters acquired from the asset at a similar time to cluster in feature space, determining a distance of the data point relative to a cluster of data points in feature space, where the cluster of data points are determined by the encoder based on inputs representing the asset over a first time period, and in response to the determined distance exceeding a predetermined distance threshold, generating an abnormal asset behaviour prediction.

There is provided a method of training an encoder model to map inputs representing nominally healthy assets to a cluster of data points. The method comprises providing an input representing a behaviour of an asset at a first point in time to the encoder model undergoing training to map the input to a data point in the feature space, wherein the encoder model is intended to cause data points relating to measured values of input parameters acquired from the same asset at similar time to cluster in feature space, providing the data point to a decoder model, to determine a reconstructed input, determining a difference between the input, and the reconstructed input, and training the encoder model based on the determined difference to map inputs representing nominally healthy assets acquired at similar times to a cluster of data points.

A fuel system for a gas turbine engine (103) is disclosed. The fuel system is configured to combust hydrogen fuel and comprises a fuel conduit (228), a first fuel pump (226) configured to operate on liquid hydrogen within the fuel conduit (228) and a second fuel pump (230) downstream in hydrogen fuel flow of the first fuel pump (226). The first fuel pump comprises one of a side channel and a regenerative pump (226) and the second fuel pump comprises a centrifugal pump (230). Methods of operation, a gas turbine engine comprising the fuel system, and an aircraft comprising the gas turbine engine are also disclosed.

A climatic test conditioning apparatus (100) for conditioning a gas turbine engine (10) for climatic testing comprises a base (110) and an inflatable wall (120) connected to the base (110). The inflatable wall (120) has at least one port for at least partial inflation and deflation of the inflatable wall (120). The at least partially inflated inflatable wall (120) and base (110) define a volume (140) that envelopes the gas turbine engine (10). Also disclosed is a system and method for climatic test conditioning a gas turbine engine (10).

A method (200) for scanning a plurality of components (102). The method (200) includes providing an imaging beam source (108), an imaging beam receiver (114), and a support platform (104). The support platform (104) is configured to rotate and/or revolve relative to the imaging beam source (108) and the imaging beam receiver (114) about one or more axes. The method (200) further includes disposing the plurality of components (102) on the support platform (104). The plurality of components (102) is positioned in a gap (118) between a first geometrical figure (120) and at least one second geometrical figure (122) in a configuration that reduces the variation in material thickness penetrated at different relative angles of rotation and/or revolution. The first geometrical figure (120) and the at least one second geometrical figure (122) are concentric.

A fuel system for a hydrogen fuelled gas turbine engine (201). The fuel system comprises a main hydrogen fuel line (206) configured to provide hydrogen fuel to a combustor (203) of the gas turbine engine (201) and a closed loop heat exchange fluid line (207) comprising a heat exchange fluid. The fuel system further comprises a first heat exchanger (208) configured to exchange heat between gas turbine engine compressor bleed air and heat exchange fluid in the heat exchange fluid line (207), a second heat exchanger (209) downstream of the first heat exchanger (208) in heat exchange fluid flow configured to exchange heat between the heated heat exchange fluid and hydrogen in the main hydrogen fuel line, and a third heat exchanger (215) downstream in main hydrogen fuel flow of the second heat exchanger (209) in main hydrogen fuel flow configured to exchange heat between a further engine fluid and heated hydrogen fuel.

A fuel system for a hydrogen fuelled gas turbine engine (201). The fuel system comprises a main hydrogen fuel line (206) configured to provide hydrogen fuel to a combustor (203) of the gas turbine engine (201) and a closed loop heat exchange fluid line (207) comprising a heat exchange fluid. The fuel system further comprises a first heat exchanger (208) configured to exchange heat between gas turbine engine compressor bleed air and heat exchange fluid in the heat exchange fluid line (207), a second heat exchanger (209) downstream of the first heat exchanger (208) in heat exchange fluid flow configured to exchange heat between the heated heat exchange fluid and hydrogen in the main hydrogen fuel line, and a third heat exchanger (215) downstream in main hydrogen fuel flow of the second heat exchanger (209) in main hydrogen fuel flow configured to exchange heat between a further engine fluid and heated hydrogen fuel.

A gas turbine engine (10) including a rear attachment (400) comprising: a plurality of angularly distributed rotational pylon connections (221, 222, 223) for coupling to a wing pylon (200) and defining a pylon connection angular extent; a plurality of angularly distributed engine connections (121, 122, 123) for coupling to a rear mount structure (117) of the gas turbine engine 10 and defining an engine connection angular extent; and a link structure extending between the pylon connections (221, 222, 223) and the engine connections (121, 122, 123); wherein the link structure, pylon connections (221, 222, 223) and engine connections (121, 122, 123) are configured to transfer a roll torque from the rear mount structure (117) to the wing pylon (200); and wherein a ratio of the engine connection angular extent to the pylon connection angular extent is at least 1.75.