Abstract: A heat exchanger includes a first regenerator core and a second regenerator core and a four-way valve coupled to a cold section of the first regenerator core and to a cold section of the second regenerator core. The four-way valve directs input air to the first regenerator core or to the second regenerator core. A high-temperature passive check valve is coupled to a hot section of the first regenerator core and to a hot section of the second regenerator core. The high-temperature passive check valve comprises an inlet header coupled to the hot section of the first regenerator core or the second regenerator core, a valve poppet coupled to a valve stem and a valve seat located on a surface parallel to a surface of the valve poppet. Air entering the inlet header moves the valve poppet away from the valve seat, creating an opening through which air passes.

Abstract: A heat exchanger includes a first regenerator core and a second regenerator core and a four-way valve coupled to a cold section of the first regenerator core and to a cold section of the second regenerator core. The four-way valve directs input air to the first regenerator core or to the second regenerator core. A high-temperature passive check valve is coupled to a hot section of the first regenerator core and to a hot section of the second regenerator core. The high-temperature passive check valve comprises an inlet header coupled to the hot section of the first regenerator core or the second regenerator core, a valve poppet coupled to a valve stem and a valve seat located on a surface parallel to a surface of the valve poppet. Air entering the inlet header moves the valve poppet away from the valve seat, creating an opening through which air passes.

Abstract: Passenger cabin ventilation air outlets located in the cabin ceiling blow air downward toward the passengers. An outlet for this location utilizes a series of high velocity jets exiting from a narrow ceiling nozzle to entrain cabin air to form a broad slow moving single jet. Three rows of slots are utilized, the outer rows to initially produce a wide air jet, and the center row to draw the outer jets back together outside of the nozzle. The center jets coalesce the outer jets into a slower moving total air stream.