Abstract: A method of extending the lifetime of brazed primary hot inlet wavy fin structures of aircraft heat exchangers includes inserting slots in the fins. The slots increase the mechanical compliance of the fins as well as act as crack arrestors should a thermally induced fracture occur. In an embodiment, the slots are inserted by EDM.

Abstract: A plate fin heat exchanger is configured to receive hot flow from a hot source and cool flow from a cool source. The plate fin heat exchanger includes a plurality of plates arranged in parallel to define a plurality of flow passages therebetween, and a set of closure bars arranged at a first side of the plurality of plates to seal a first set of the flow passages against ingress of the hot flow, thereby directing the hot flow into a second set of the flow passages. Each respective closure bar includes an inner core formed of a first material having a first coefficient of thermal expansion and an outer cladding arranged about the inner core, the outer cladding formed of a second material having a second coefficient of thermal expansion. The first coefficient of thermal expansion is less than the second coefficient of thermal expansion.

Abstract: A plate fin heat exchanger is configured to receive hot flow from a hot source and cool flow from a cool source. The plate fin heat exchanger includes a plurality of plates arranged in parallel to define a plurality of flow passages there between, and a set of closure bars arranged at a first side of the plurality of plates to seal a first set of the flow passages against ingress of the hot flow, thereby directing the hot flow into a second set of the flow passages. Each respective closure bar includes an inner core formed of a first material having a first coefficient of thermal expansion and an outer cladding arranged about the inner core, the outer cladding formed of a second material having a second coefficient of thermal expansion. The first coefficient of thermal expansion is less than the second coefficient of thermal expansion.

Abstract: A plate fin heat exchanger includes a plate fin core having a plurality of plates defining a set of hot air passages extending from a hot air inlet region of the plate fin core to a hot air outlet region of the plate fin core and a set of cool air passages extending from a cool air inlet region of the plate fin core to a cool air outlet region of the plate fin core. The plate fin heat exchanger further includes a mounting flange circumscribing the cool air outlet region. At least a portion of the mounting flange has a plurality of heat transfer structures that extend into a flow path of cooling air exiting the cool air outlet region of the plate fin core.

Abstract: A heat exchanger includes a plurality of first fluid passages configured to receive a first stream and a plurality of second fluid passages each formed between two first fluid passages. Each first fluid passage includes a first plate and a second plate parallel to the first plate. The first plate and second plate are connected by two closure bars. The first fluid passage also includes a fin pack having a plurality of fins connected to the first and second plate, and configured for the first stream to flow around the fins. The fins have a cross-sectional profile that is bowed at non-operational temperatures and is configured to flex under a thermal load without exceeding the tensile or fatigue strength of the fin. Each second fluid passage is configured to receive a second stream and is configured to allow heat to indirectly exchange between the first stream and the second stream.

Abstract: A plate fin heat exchanger includes a plurality of finned cold layers configured to conduct a first fluid, and a plurality of finned warm layers configured to conduct a second fluid. The finned warm layers include an inlet side and an outlet side. A first portion of fins of at least one finned warm layer of the plurality of finned warm layers includes a plurality of aligned peaks and valleys defining a wave configuration for each fin of the first portion of fins. An upstream leading edge of the first portion of fins begins at a point of the wave configuration that is at least one of the peaks and valleys.

Abstract: In one aspect, a plate fin heat exchanger is provided. The heat exchanger includes a plurality of finned cold layers configured to conduct a first fluid and a plurality of finned warm layers configured to conduct a second fluid. The finned warm layers include an inlet side, an outlet side, a first portion of fins at the inlet side, and a second portion of fins at the outlet side.

Abstract: A method of extending the lifetime of brazed primary hot inlet wavy fin structures of aircraft heat exchangers includes inserting slots in the fins. The slots increase the mechanical compliance of the fins as well as act as crack arrestors should a thermally induced fracture occur. In an embodiment, the slots are inserted by EDM.

Abstract: A plate fin heat exchanger includes a plate fin core having a plurality of plates defining a set of hot air passages extending from a hot air inlet region of the plate fin core to a hot air outlet region of the plate fin core and a set of cool air passages extending from a cool air inlet region of the plate fin core to a cool air outlet region of the plate fin core. The plate fin heat exchanger further includes a mounting flange circumscribing the cool air outlet region. At least a portion of the mounting flange has a plurality of heat transfer structures that extend into a flow path of cooling air exiting the cool air outlet region of the plate fin core.

Abstract: A plate fin heat exchanger is configured to receive hot flow from a hot source and cool flow from a cool source. The plate fin heat exchanger includes a plurality of plates arranged in parallel to define a plurality of flow passages there between, and a set of closure bars arranged at a first side of the plurality of plates to seal a first set of the flow passages against ingress of the hot flow, thereby directing the hot flow into a second set of the flow passages. Each respective closure bar includes an inner core formed of a first material having a first coefficient of thermal expansion and an outer cladding arranged about the inner core, the outer cladding formed of a second material having a second coefficient of thermal expansion. The first coefficient of thermal expansion is less than the second coefficient of thermal expansion.

Abstract: A check valve (10) includes a valve housing (14) having at least one valve opening (16). At least one petal (12) is located in the valve housing (14) and is configured to substantially cover the at least one valve opening (16) when the at least one petal (12) is in a closed position. The at least one petal (12) is rotable about a hinge axis (22) toward an open position thereby allowing fluid to flow through the at least one valve opening (16). The check valve (10) includes at least one compliant petal stop (24), (36) to prevent rotation of the at least one petal (12) beyond the open position.

Abstract: A check valve (10) includes a valve housing (14) having at least one valve opening (16). At least one petal (12) is located in the valve housing (14) and is configured to substantially cover the at least one valve opening (16) when the at least one petal (12) is in a closed position. The at least one petal (12) is rotable about a hinge axis (22) toward an open position thereby allowing fluid to flow through the at least one valve opening (16). The check valve (10) includes at least one compliant petal stop (24), (36) to prevent rotation of the at least one petal (12) beyond the open position.