Abstract: A diffuser pipe has a tubular body defining a pipe center axis extending therethrough. The tubular body includes a first portion extending in a generally radial direction from an inlet of the tubular body, a second portion extending in a generally axial direction and terminating at a pipe outlet, and a bend portion fluidly linking the first portion and the second portion. The tubular body has a length defined between the inlet and the pipe outlet. The tubular body has cross-sectional profiles defined in a plane normal to the pipe center axis. An area of the cross-sectional profile at the pipe outlet is at least 20% greater than an area of the cross-sectional profile at a point upstream from the pipe outlet a distance corresponding to 10% of the length of the tubular body.

Abstract: There is described herein methods and systems for detecting a shaft event, such as a shaft shear, a shaft decoupling, and/or a shaft failure in a gas turbine engine. The method comprises determining a detection threshold as a set of threshold values for a spool speed of a first spool of the engine and a load transfer through a shaft of a second spool of the engine different from the first spool, the set of threshold values varying throughout a flight envelope, the detection threshold defining, for each spool speed value, at least one load transfer value beyond which a shaft event is detected. Operation values of the spool speed and the load transfer are obtained during operation of the engine, and the operation values are compared to the detection threshold. The shaft event is detected when the operation values are below the detection threshold.

Abstract: There is described herein methods and systems for detecting a shaft event, such as a shaft shear, a shaft decoupling, and/or a shaft failure in a gas turbine engine. The method comprises determining a detection threshold as a set of threshold values for a spool speed of a first spool of the engine and a load transfer through a shaft of a second spool of the engine different from the first spool, the set of threshold values varying throughout a flight envelope, the detection threshold defining, for each spool speed value, at least one load transfer value beyond which a shaft event is detected. Operation values of the spool speed and the load transfer are obtained during operation of the engine, and the operation values are compared to the detection threshold. The shaft event is detected when the operation values are below the detection threshold.

Abstract: An inlet guide assembly for a turbine receiving a pulsed flow, including a duct having an internal volume, and an inlet port, first outlet nozzle and second outlet nozzle each communicating with the internal volume. The inlet port is configured to receive at least part of the pulsed flow. The first and second outlet nozzles each define a respective nozzle area communicating between the internal volume and a flow path of the turbine. The first and second outlet nozzles are spaced from one another with the first outlet nozzle located closer to the inlet port than the second outlet nozzle relative to a flow direction through the duct, the nozzle area of the first outlet nozzle being smaller than the nozzle area of the second outlet nozzle. A compound engine assembly and method of introducing a pulsed flow into a flow path of a turbine are also discussed.

Abstract: An inlet guide assembly for a turbine receiving a pulsed flow, including a duct having an internal volume, and an inlet port, first outlet nozzle and second outlet nozzle each communicating with the internal volume. The inlet port is configured to receive at least part of the pulsed flow. The first and second outlet nozzles each define a respective nozzle area communicating between the internal volume and a flow path of the turbine. The first and second outlet nozzles are spaced from one another with the first outlet nozzle located closer to the inlet port than the second outlet nozzle relative to a flow direction through the duct, the nozzle area of the first outlet nozzle being smaller than the nozzle area of the second outlet nozzle. A compound engine assembly and method of introducing a pulsed flow into a flow path of a turbine are also discussed.