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 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 core assembly for a heat exchanger includes a plurality of parting sheets defining a plurality of fluid passages including a plurality of first fluid passages and a plurality of second fluid passages arranged in an alternating arrangement, wherein each of the plurality of parting sheets comprises a thickness of about 0.016?. Also included is a plurality of first fluid passage fins disposed between the plurality of parting sheets within each of the plurality of first fluid passages. Further included is a plurality of second fluid passage fins disposed between the plurality of parting sheets within each of the plurality of second fluid passages. Yet further included is a plurality of closure bars disposed between respective pairs of the plurality of parting sheets.

Abstract: A heat exchanger assembly includes a core assembly having air passages that are closed off on at least one side by a closure bar. A reinforcing bar is received within a channel of the closure bar to create an interface with substantially no gaps that may accumulate moisture within the core assembly. The prevention of moisture accumulation at the interface between the reinforcing bar and the closure bar prevents potential damage caused by freezing.

Abstract: A heat exchanger assembly includes a core assembly having air passages that are closed off on at least one side by a closure bar. A reinforcing bar is received within a channel of the closure bar to create an interface with substantially no gaps that may accumulate moisture within the core assembly. The prevention of moisture accumulation at the interface between the reinforcing bar and the closure bar prevents potential damage caused by freezing.