Patent ID: 7527087

Claim:
A heat exchanger, comprising: a first end tank; a second end tank opposite the first end tank; a plurality of first tubes in fluid communication with the first and second end tanks, the plurality of first tubes adapted to have a first fluid flow therethrough; a plurality of second tubes in fluid communication with the first and second end tanks, the plurality of second tubes adapted to have a second fluid, different from the first fluid, flow therethrough; a plurality of fins disposed between the first and second tubes, with the first and second tubes and the fins being generally coplanar relative to each other; an inlet and an outlet on the first end tank for the first fluid flow; an inlet on the first end tank and an outlet on the second end tank for the second fluid flow; and means for performing a passive bypass function including at least one of: a passageway formed within each of the plurality of first tubes and having partitions which divide the passageway; or at least one of the first tubes, second tubes or a plurality of third tubes having a hydraulic diameter other than that of the other tubes; wherein at least one of the first fluid or second fluid is a radiator fluid.