Abstract: Methods and apparatus are provided for predicting ice formation on and shedding from blades of an air cycle machine (“ACM”) turbine. The method comprises generating operational condition data representative of ACM turbine operating conditions using a software model of the ACM, determining an amount of ice formation on the blades of the ACM turbine, and determining an amount of ice shed from the blades of the ACM turbine. The apparatus comprises means for generating operational condition data representative of ACM turbine operating conditions using a software model of the ACM, means for determining an amount of ice formation on the blades of the ACM turbine, and means for determining an amount of ice shed from the blades of the ACM turbine. In some embodiments, the means and apparatus may also involve predicting ACM wear, based at least in part on the predicted ice formation and shedding.

Abstract: An environmental control system for an aircraft cabin includes a plurality of electrically-driven ported shroud cabin air compressors, each cabin air compressor compressing ram air received from the aircraft exterior, a heat exchange circuit comprising a primary heat exchanger receiving airflow from at least one of the cabin air compressors, and the secondary heat exchanger supplying airflow to the aircraft cabin, and an air cycle machine comprising a compressor adapted to receive airflow from the primary heat exchanger and supply compressed air to the secondary heat exchanger. The environmental control system may further comprise an air recirculation system, having an aft recirculation fan adapted to receive a portion of recirculation air from the aircraft cabin, and a recirculation heat exchanger, disposed in the heat exchange circuit in series with the primary and secondary heat exchangers, and adapted to receive airflow from the aft recirculation fan.

Abstract: A compressor ported shroud takes bearing compressed air from the shroud of the compressor before it is completely compressed and delivers it to foil bearings. The compressed air has a lower pressure and temperature than compressed outlet air. The lower temperature of the air means that less air needs to be bled off from the compressor to cool the foil bearings. This increases the overall system efficiency due to the reduced mass flow requirements of the lower temperature air. By taking the air at a lower pressure, less work is lost compressing the bearing cooling air.

Abstract: A flow adjustment member may be provided in a turbine nozzle to limit the flow therethrough. Turbine nozzle flow is an important performance characteristic that may be difficult to control by conventional drilling or machining manufacturing methods. The turbine nozzle has a flow adjustment member protruding into a nozzle passage, thereby reducing airflow through the nozzle passage. The turbine nozzle according to the present invention provides simple and convenient adjustment of the flow that may be allowed to pass through a turbine nozzle onto a turbine wheel of a turbo machine.