Abstract: An electric propulsion unit comprising a housing, an AC motor, a beta rod, a propeller, a governor, an inverter, and a controller. The AC motor is disposed within the housing and includes bearings supported inside the housing, a hollow motor shaft rotatably coupled to the housing by the bearings, a stator which is supported by the housing, and a rotor which is mounted to the hollow motor shaft. The beta rod is axially translatable inside the hollow motor shaft. The propeller is mechanically coupled to the hollow motor shaft. The propeller includes propeller blades having an adjustable pitch angle which depends on an axial position of the beta rod. The governor is configured to adjust a pitch angle of the propeller blades by actuating axial translation of the beta rod. The controller is disposed inside the housing and configured to control the pitch angle of the propeller blades.

Abstract: Active fluid control systems and related methods are disclosed. A disclosed example active fluid control system includes a plurality of plenums coupled together to define a fluid flow passageway, and a plurality of fluidic actuators coupled to outer surfaces of respective ones of the plenums. The fluidic actuators define actuator inlets and actuator outlets. The fluid flow passageway defined by the plenums to fluidly couple the fluidic actuators and a pressurized fluid supply source. The plenums are configured to couple to an aircraft structure supporting an aerodynamic surface to enable the actuator outlets to be mounted to the aerodynamic surface. The fluidic actuators are configured to provide the pressurized fluid to the aerodynamic surface to modify an aerodynamic characteristic of the aerodynamic surface.

Abstract: An electric propulsion unit comprising a housing, an AC motor, a beta rod, a propeller, a governor, an inverter, and a controller. The AC motor is disposed within the housing and includes a plurality of bearings supported inside the housing, a hollow motor shaft rotatably coupled to the housing by the plurality of bearings, a stator which is supported by the housing, and a rotor which is mounted to the hollow motor shaft. The beta rod is axially translatable inside the hollow motor shaft. The propeller is mechanically coupled to the hollow motor shaft. The propeller includes propeller blades having an adjustable pitch angle which depends on an axial position of the beta rod. The governor is configured to adjust a pitch angle of the propeller blades by actuating axial translation of the beta rod. The inverter is disposed within the housing and connected to receive DC power for conversion into AC power.

Abstract: Filtration apparatus are disclosed. An example filtration apparatus includes a housing including a plurality of walls defining a cavity, a filter located in the cavity, and a cleanout system coupled to the housing. The cleanout system includes a cleanout passageway between an outer surface of the housing and the filter. The cleanout system includes a cleanout inlet accessible from the outer surface of the housing and a cleanout outlet in fluid communication with the filter. The cleanout system enables removal of particulate from the filter without removing the filter from the housing.

Abstract: Example active flow control systems and methods for aircraft are described herein. An example an active flow control system includes a plenum, a plurality of nozzles fluidly coupled to the plenum, configured to eject high pressure air across a control surface, a compressor to supply pressurized air to the plenum, an electric motor to drive the compressor, and a control system to determine an amount of power input to the electric motor, determine a current speed of the electric motor, and determine a fault has occurred in the active flow control system based on the current speed of the electric motor.

Abstract: Cleanout systems are disclosed. An example environmental control system includes an exhaust plenum to exhaust cooling fluid from a heat exchanger outlet of a heat exchanger, and a cleanout system coupled to the exhaust plenum adjacent the heat exchanger outlet. The cleanout system includes a cleanout passageway to fluidly couple a cleanout inlet accessible from an outer surface of the exhaust plenum and a cleanout outlet in fluid communication with the heat exchanger outlet. The cleanout system is to enable removal of particulate from the heat exchanger without disassembling the heat exchanger from the exhaust plenum or an air intake.

Abstract: Filtration apparatus are disclosed. An example filtration apparatus includes a housing including a plurality of walls defining a cavity, a filter located in the cavity, and a cleanout system coupled to the housing. The cleanout system includes a cleanout passageway between an outer surface of the housing and the filter. The cleanout system includes a cleanout inlet accessible from the outer surface of the housing and a cleanout outlet in fluid communication with the filter. The cleanout system enables removal of particulate from the filter without removing the filter from the housing.

Abstract: Cleanout systems are disclosed. An example environmental control system includes an exhaust plenum to exhaust cooling fluid from a heat exchanger outlet of a heat exchanger, and a cleanout system coupled to the exhaust plenum adjacent the heat exchanger outlet. The cleanout system includes a cleanout passageway to fluidly couple a cleanout inlet accessible from an outer surface of the exhaust plenum and a cleanout outlet in fluid communication with the heat exchanger outlet. The cleanout system is to enable removal of particulate from the heat exchanger without disassembling the heat exchanger from the exhaust plenum or an air intake.

Abstract: Active fluid control systems and related methods are disclosed. A disclosed example active fluid control system includes a plurality of plenums coupled together to define a fluid flow passageway, and a plurality of fluidic actuators coupled to outer surfaces of respective ones of the plenums. The fluidic actuators define actuator inlets and actuator outlets. The fluid flow passageway defined by the plenums to fluidly couple the fluidic actuators and a pressurized fluid supply source. The plenums are configured to couple to an aircraft structure supporting an aerodynamic surface to enable the actuator outlets to be mounted to the aerodynamic surface. The fluidic actuators are configured to provide the pressurized fluid to the aerodynamic surface to modify an aerodynamic characteristic of the aerodynamic surface.