A passenger cabin air distribution system includes a ventilation system and an ejector-diffuser. The ventilation system is operable to provide a conditioned air. The ejector-diffuser is positioned to receive a flow of the conditioned air from the ventilation system. The ejector-diffuser includes an induction unit and a diffuser section. The induction unit includes a secondary inlet in communication with a cabin air from a passenger cabin and is configured to mix the flow of the conditioned air with an induced flow of the cabin air into a mixed air. The diffuser section includes a discharge to eject the mixed air to the passenger cabin. The diffuser section is shaped to provide for efficient mixing with low backpressure in order to maintain the low motive pressure in the nozzle.

A method of determining and controlling a weight flow in an environmental control system includes sensing, using a turbine inlet temperature sensor, a turbine inlet temperature. A turbine inlet pressure is sensed using a turbine inlet pressure sensor. A turbine outlet pressure is sensed using a turbine outlet pressure sensor. A rotational shaft speed of a shaft is sensed using a rotational shaft speed sensor. The sensed turbine inlet temperature, the sensed turbine inlet pressure, the sensed turbine outlet pressure, and the sensed rotational shaft speed are received by a controller. A flow coefficient is determined by the controller using the turbine inlet pressure, the turbine outlet pressure, the shaft speed, and a Turbine Flow Coefficient Map. A weight flow through the turbine is determined by the controller using the flow coefficient, the turbine inlet temperature, a nozzle area, and the turbine inlet pressure.

An aircraft environmental control system includes means for mixing and conditioning bleed air from a bleed air input and recirculation air from an aircraft interior to provide mixed, conditioned air to the aircraft interior. The system also includes a first contaminant removal device and a second contaminant removal device arranged in a path of at least part of the recirculation air, prior to the means for mixing and conditioning, and a valve (SV1) arranged to alternate flow of recirculation air through the first and second contaminant removal devices.

Apparatus and methods for providing a desired volumetric conditioned airflow rate and for reducing noise level, airflow recirculation and airflow separation are disclosed. An example apparatus includes a nozzle housing having a pair of opposing sidewalls and a front and back wall that define an airflow passage. The airflow passage has a centerline extending between the inlet and the outlet and has a plurality of cross-sections taken perpendicular to the centerline that collectively define a smooth contour along a length of the airflow passage. The cross-sections each have a thickness between the front and back wall that is greater at side edges than at the centerline. The thickness of the cross-sections decreases along a length of at least a first portion of the nozzle housing. A width of each of the cross-sections between the sidewalls increases along the length of at least the first portion of the nozzle housing.

A manned or unmanned aircraft has a main body with a circular shape and a circular outer periphery. One or more rotor blades extend substantially horizontally outward from the main body at or about the circular outer periphery. In addition, one or more counter-rotation blades extend substantially horizontally outward from said main body at or about the circular outer periphery, but vertically offset from the main rotor blades.

An aircraft cabin blower system comprises a cabin blower including a compressor configured to provide air to a cabin of the aircraft; a variable drive system configured to drive the compressor and including an electric variator and a summing gearbox; and a main transmission configured, when operating in a blower mode, to receive mechanical power from a gas turbine engine and input mechanical power to the summing gearbox in a forward direction; and configured, when operating in a starter mode, to receive mechanical power from the summing gearbox and input mechanical power to the gas turbine engine. The aircraft cabin blower system further includes a first one-way rotation device adapted to permit free rotation of the main transmission in the forward direction and to prevent rotation of the main transmission in a reverse direction opposite to the forward direction.

This disclosure describes at least embodiments of an aircraft monitoring system for an electric or hybrid airplane. The aircraft monitoring system can be constructed to enable the electric or hybrid aircraft to pass certification requirements relating to a safety risk analysis. The aircraft monitoring system can have different subsystems for monitoring and alerting of failures of a component, such as a battery pack, a motor controller, and/or a motors. The failures that pose a greater safety risk may be monitored and indicated by one or more subsystems without use of programmable components.

A metamaterial-based substrate (meta-substrate) for piezoelectric energy harvesters. The design of the meta-substrate combines kirigami and auxetic topologies to create a high-performance platform including preferable mechanical properties of both metamaterial morphable structures. The creative design of the meta-substrate can improve strain-induced vibration applications in structural health monitoring, internet-of-things systems, micro-electromechanical systems, wireless sensor networks, vibration energy harvesters, and other applications whose efficiency is dependent on their deformation performance. The meta-substrate energy harvesting device includes a meta-material substrate comprising an auxetic frame having two kirigami cuts and a piezoelectric element adhered to the auxetic frame by means of a thin layer of elastic glue.

A disclosed drive assembly for an auxiliary power unit includes a first drive shaft driven by an auxiliary power unit, a second drive shaft driven by a first electric motor, a differential gear system including a ring gear driven by the second drive shaft, a and planet gears supported within a carrier attached to the ring gear. The first drive shaft and an output shaft are coupled to the planet gears and a generator is driven by the output shaft. The electric motor and the auxiliary power unit combine to drive the output shaft.

An air cycle machine includes an air inlet connected to an air cycle compressor. Air downstream of the air cycle compressor is connected to be delivered across a first turbine. The air cycle compressor is driven by the first turbine through a shaft. Air downstream of the first turbine is connected to a second turbine. The second turbine is connected to deliver air downstream. The second turbine is connected with a second shaft to drive a fan rotor. The fan rotor delivers a source of air across a primary heat exchanger positioned between the inlet and the air cycle compressor. The air cycle compressor and the first turbine are formed of a metal. The second turbine and the fan rotor are formed of non-metallic materials.