MODULAR HEAT EXCHANGER FOR AN AIRCRAFT POWERPLANT

An apparatus is provided for an aircraft powerplant. This apparatus includes a heat exchanger (20). The heat exchanger (20) includes a frame (22), a plurality of heat exchanger cores (24), a first flowpath (96) and a second flowpath (98). The frame (22) extends circumferentially about an axis (26). The frame (22) includes a plurality of receptacles (48) within an interior of the frame (22). Each of the heat exchanger cores (24) is housed within a respective one of the receptacles (48). The first flowpath (96) extends in a first direction across the heat exchanger (20) and through the plurality of heat exchanger cores (24). The second flowpath (98) extends in a second direction across the heat exchanger (20) and through the plurality of heat exchanger cores (24).