US Patent 11555659 Multi-scale heat exchanger core

A heat exchanger core includes a first side, a second side, a third side, and a fourth side. A first layer includes a first width extending in a first direction, a first length extending in a second direction, a first height extending in a third direction, and a first plurality of passages, which extend from an inlet to an outlet. A second layer includes a second width extending in the first direction, a second length extending in the second direction, a second height extending in the third direction, and a second plurality of passages extending from the first side to the second side. The first and second plurality of passages are adjacent to one another. The first and second plurality of passages include a sinusoidal profile in the third direction and a sinusoidal profile in the first direction.