Multifurcating heat exchanger with independent baffles

A heat exchanger core 102 includes a plurality of unit cells 108 coupled together to define a first passageway (110, fig 2) for a first fluid flow within an interior volume and a second passageway (114) for a second fluid flow at an exterior surface. Each unit cell includes a plurality of first openings 130 into the interior volume and forms the second passageway between the plurality of unit cells. The assembly is shaped to combine and divide the first fluid in the first passageway portion and combine and split the second fluid in the second passageway portion during heat exchange between the first and second fluids. Each second passageway portion receives the second fluid from three other second passageway portions. The heat exchanger further includes at least one baffle 105 in at least one of the first passageway or the second passageway to route the first fluid flow independently from the second fluid flow. A heat exchanger where the at least one baffle is arranged to independently block the first passageway without blocking the second passageway is also claimed.