Abstract: An outflow valve is provided. The outflow valve includes a frame and a first door rotatably coupled to the frame. The first door has a first side opposite a second side and a bellmouth. The bellmouth is defined by a super-ellipse, with a major axis of the super-ellipse substantially parallel to the second side and a minor axis of the super-ellipse substantially perpendicular to the second side. The outflow valve also includes a second door rotatably coupled to the frame. The first door and the second door are substantially simultaneously movable between at least a first position and a second position.

Abstract: An outflow valve is provided. The outflow valve includes a frame and a first door rotatably coupled to the frame. The first door has a first side opposite a second side and a bellmouth. The bellmouth is defined by a super-ellipse, with a major axis of the super-ellipse substantially parallel to the second side and a minor axis of the super-ellipse substantially perpendicular to the second side. The outflow valve also includes a second door rotatably coupled to the frame. The first door and the second door are substantially simultaneously movable between at least a first position and a second position.

Abstract: A gas distribution system may include a gas mass flow sensor with a resistive element configured to be heated, a thermally conductive shell surrounding the resistive element and heat-transfer control elements. The shell may include a leading surface oriented substantially orthogonal to a direction of gas flow. The heat-transfer control elements may be positioned to focus heat transfer from the resistive element through the leading surface of the shell so that a rate of heat transfer is independent from the variations in flow configuration.

Abstract: A gas distribution system may include a gas mass flow sensor with a resistive element configured to be heated, a thermally conductive shell surrounding the resistive element and heat-transfer control elements. The shell may include a leading surface oriented substantially orthogonal to a direction of gas flow. The heat-transfer control elements may be positioned to focus heat transfer from the resistive element through the leading surface of the shell so that a rate of heat transfer is independent from the variations in flow configuration.

Abstract: An environmental control system (ECS) for an aircraft may include a mixing diffuser configured to admit a stream of cold air and a stream of hot air and a reheater-condenser fluidly coupled with an output end of the mixing diffuser. The mixing diffuser may include a diffuser cone with a plurality of holes configured to allow passage of hot air into the stream of cold air so that the cold air and the hot air are combined to produce a mixed airstream. The reheater-condenser may include mixing tabs configured to produce further mixing of the mixed airstream.

Abstract: A bleed valve assembly for discharging bleed air into a gas turbine engine bypass plenum includes a bleed flow duct, a bleed valve, and a flow deflector. The bleed flow duct is contoured such that it delivers uniformly flowing bleed air to the flow deflector when the bleed valve is in the open position. The flow deflector has a plurality of openings formed therein. Each opening fluidly communicates the bleed air flow passage with the bypass plenum and is oriented at a discharge angle such that bleed air is discharged from each opening in a direction that does not have a vector component in the direction in which air is flowing in the bypass plenum.

Abstract: A waterjet propulsion apparatus having a five blade rotor and an eight blade stator that are located within housing sections that define a water flowpath. The housing and hub are designed such that in operation a nonuniform loading arises on the rotor blades whereby greater pressure impinges on the tip area of the rotor blade than at the hub area of the rotor blade. This configuration increases the efficiency of the waterjet while minimizing negative effects of cavitation.

Abstract: An air turbine starter is provided that includes a check valve assembly for placement between a first environment, at least a portion of which is at a first pressure (P1), and a second environment, at least a portion of which is at a second pressure (P2), wherein the difference between the first and second pressures generate a pressure force (Fp). The check valve assembly comprises a valve element disposed between the valve seat and the valve body, the valve element capable of being acted upon by a gravitational force (Fw), a viscous force of the fluid to be communicated between the gearbox assembly and the starter housing (Fv), a buoyancy force of the valve element (Fb), and the pressure force on the valve element (Fp), the valve element further configured to translate axially to a closed position when P2<P1 and Fw<Fv+Fb+Fp.

Abstract: A waterjet propulsion apparatus having a five blade rotor and an eight blade stator that are located within housing sections that define a water flowpath. The housing and hub are designed such that in operation a nonuniform loading arises on the rotor blades whereby greater pressure impinges on the tip area of the rotor blade than at the hub area of the rotor blade. This configuration increases the efficiency of the waterjet while minimizing negative effects of cavitation.