Heat exchanger including cross channel communication

A method, the method comprising:

• forming a first flow channel of a heat exchanger, the first flow channel having a first flow channel inlet and a first flow channel outlet;
• forming a second flow channel of the heat exchanger, the second flow channel having a second flow channel inlet and a second flow channel outlet;
• and
• separating the first flow channel from the second flow channel with a fin, wherein the fin is a wavy fin defining a series of peaks and valleys along a length of the fin, the peaks and valleys configured to change the direction of flow through the first flow channel or the second flow channel, wherein:
• a first portion of the length of the fin defines a first solid fin portion that does not define any apertures,
• a second portion of the length of the fin defines a first porous fin portion defining a plurality of randomly distributed apertures,
• the first porous fin portion allows a fluid to flow between the first flow channel and the second flow channel if one of the first flow channel inlet or second flow channel inlet becomes constricted through a buildup of foreign object debris,
• the first porous fin portion is located such that a vector defined by a momentum of fluid flowing in the first flow channel or the second flow channel intersects with the wavy fin at a center of the first porous fin portion,
• the first porous fin portion extends downstream along a length of the wavy fin from a first end of the first porous fin portion to a second end of the first porous fin portion, wherein the center of the first porous fin portion is downstream of a local peak or valley of the wavy fin,
• the first end of the first porous fin portion is aligned with a peak or a valley of the wavy fin,
• the first solid fin portion is disposed along a relatively straight length of the fin, and
• a second porous fin portion is displaced from the first porous fin portion by a second solid fin portion.