Heat exchanger with varied louver angles

Abstract

A heat exchanger assembly includes spaced apart tubes and a fin. The fin extends between and in thermal contact with adjacent tubes. The fin defines a planar portion between adjacent tubes. The planar portion defines a louver. The louver defines an axis about which the louver is rotated relative to the planar portion when the louver is formed. A middle portion of the louver is rotated about the axis to a first angle. A top portion of the louver is rotated about the axis to a second angle greater than the first angle such that the louver angle is varied along the axis. The louver may be characterized along the axis by a continuous transition of angle from the first angle to the second angle. A bottom portion of the louver may be rotated about the axis to a third angle greater than the first angle.

We claim: 
     
         1 . A heat exchanger assembly comprising:
 a plurality of parallel spaced apart tubes configured to convey coolant therethrough; and   a fin extended between and in thermal contact with adjacent tubes, wherein the fin defines a planar portion between the adjacent tubes, the planar portion defines a louver, the louver defines an axis about which the louver is rotated relative to the planar portion when the louver is formed, and a middle portion of the louver is rotated about the axis to a first angle, wherein   a top portion of the louver is rotated about the axis to a second angle greater than the first angle such that the louver angle is varied along the axis.   
     
     
         2 . The assembly in accordance with  claim 1 , wherein the louver is characterized along the axis by a continuous transition of angle from the first angle to the second angle. 
     
     
         3 . The assembly in accordance with  claim 1 , wherein a bottom portion of the louver is rotated about the axis to a third angle greater than the first angle. 
     
     
         4 . The assembly in accordance with  claim 3 , wherein the third angle is substantially equal to the second angle. 
     
     
         5 . The assembly in accordance with  claim 3 , wherein the louver is characterized along the axis by a continuous transition of angle from the second angle to the first angle, and from the first angle to the third angle. 
     
     
         6 . The assembly in accordance with  claim 5 , wherein the third angle is substantially equal to the second angle. 
     
     
         7 . The assembly in accordance with  claim 1 , wherein a first louver defines a first axis offset from the planar portion in first direction, and a second louver defines a second axis offset from the planar portion in a second direction opposite the first direction. 
     
     
         8 . The assembly in accordance with  claim 1 , wherein the fin includes a first planar portion adjacent to a second planar portion, and the fin is configured to define a radiused portion so the first planar portion is parallel to the second planar portion.