Abstract: There is disclosed a centrifugal compressor including an impeller rotatable about an axis and a diffuser downstream of the impeller. The diffuser has walls delimiting flow passages. Plasma actuators are positioned adjacent the walls and are operatively connectable to a source of electricity. The plasma actuators have a first electrode, a second electrode, and a dielectric layer therebetween. The first electrode is upstream of the second electrode. The first electrode is exposed to the flow passage. The second electrode is shielded from the flow passage by the dielectric layer. The plasma actuators are operable to generate an electric field through the dielectric layer. The plasma actuators are located closer to inlets of the flow passage than to outlets of the flow passages. A method of operating the compressor is disclosed.

Abstract: Systems and Methods are described for testing engine performance in-flight in an aircraft having a first engine and a second engine. The method comprises operating the first engine at a first power level in an output speed governing mode, operating the second engine at a second power level greater than the first power level in a core speed governing mode concurrently with the first engine operating at the first power level in the output speed governing mode, and performing an engine performance test on the second engine while the second engine is at the second power level in the core speed governing mode.

Abstract: A method and system for monitoring a temperature of a gas turbine engine are described. The method comprises obtaining individual sensor readings from functioning temperature sensors of a sensor array, where a number of the functioning temperature sensors is less than a total number of temperature sensors in the sensor array; applying correction factors to the individual sensor readings of the functioning temperature sensors based on deviations of the individual sensor readings from a total average temperature of all the temperature sensors in the array, to obtain corrected individual sensor readings; and determining a corrected total average temperature as a sum of the corrected individual sensor readings divided by the number of functioning temperature sensors.

Abstract: Systems and methods for operating a rotorcraft engine are described herein. Measurements indicative of at least one of current temperature and current pressure at an inlet of the engine are obtained from at least one sensor while the rotorcraft is in flight. At least one current inlet loss is determined from the measurements. Current available engine power of the rotorcraft engine is determined based on the at least one current inlet losses. A visual indication of the current available engine power is produced via a flight display.

Abstract: A compressor diffuser for a gas turbine engine includes a plurality of diffuser passages including a first portion having a radial component, a second portion having an axial component, and a curved portion fluidly connecting the first portion and the second portion. The diffuser passages having a throat located within the first portion thereof, and including a first subset of passages and a second subset of passages. The throats of the first subset of passages have a first throat area that is different than a throat area of the throats of the second subset of passages.

Abstract: A system and method for detecting inlet temperature distortion of an engine are described. The method comprises obtaining an outside air temperature from at least one first sensor, obtaining an inlet temperature of the engine from at least one second sensor, determining an inlet temperature distortion based on a difference between the outside air temperature and the inlet temperature, comparing the inlet temperature distortion to a threshold, and issuing an alert when the inlet temperature distortion exceeds the threshold.

Abstract: There is disclosed a centrifugal compressor including an impeller rotatable about an axis and a diffuser downstream of the impeller. The diffuser has walls delimiting flow passages. Plasma actuators are positioned adjacent the walls and are operatively connectable to a source of electricity. The plasma actuators have a first electrode, a second electrode, and a dielectric layer therebetween. The first electrode is upstream of the second electrode. The first electrode is exposed to the flow passage. The second electrode is shielded from the flow passage by the dielectric layer. The plasma actuators are operable to generate an electric field through the dielectric layer. The plasma actuators are located closer to inlets of the flow passage than to outlets of the flow passages. A method of operating the compressor is disclosed.

Abstract: A compressor diffuser for a gas turbine engine includes a plurality of diffuser passages including a first portion having a radial component, a second portion having an axial component, and a curved portion fluidly connecting the first portion and the second portion. The diffuser passages having a throat located within the first portion thereof, and including a first subset of passages and a second subset of passages. The throats of the first subset of passages have a first throat area that is different than a throat area of the throats of the second subset of passages.