Arrangement of pedestals of varying aspect ratio for dual-wall cooling of an airfoil

An airfoil including an arrangement of pedestals of varying aspect ratio for dual-wall cooling, the airfoil comprising:

• a spar having a pressure side wall and a suction side wall meeting at a leading edge and a trailing edge of the airfoil, each of the pressure side wall and the suction side wall including raised features on an outer surface thereof, an interior of the spar including one or more coolant cavities;
• a pressure side coversheet overlying the pressure side wall, an inner surface of the pressure side coversheet being in contact with the raised features on the outer surface of the pressure side wall, thereby defining pressure side flow pathways between the pressure side wall and the pressure side coversheet, the pressure side flow pathways being in fluid communication with the one or more coolant cavities;
• and
• a suction side coversheet overlying the suction side wall, an inner surface of the suction side coversheet being in contact with the raised features on the outer surface of the suction side wall, thereby defining suction side flow pathways between the suction side wall and the suction side coversheet, the suction side flow pathways being in fluid communication with the one or more coolant cavities,
• wherein the raised features on the outer surface of the pressure side wall and/or the suction side wall include an arrangement of pedestals, each pedestal comprising an aspect ratio in a range from 1:1 to 5:1, the pedestals in the arrangement having a cross-sectional shape selected from the group consisting of hexagonal and hexangular, and
• wherein the aspect ratio of the pedestals is varied within the arrangement.