US Patent 8371291 Flow modification device

An air flow device includes a flow passage having opposite ends. The flow passage (30) is divided into a plurality of sequential portions between the ends including an inlet portion (42) extending into the flow passage (30) from an inlet end (34) an outlet portion (36) disposed at the opposite end of the flow passage (30) from the inlet portion (34), and at least one intermediate passage portion (44) between the inlet passage portion and the outlet passage portion. Each of a plurality of divider sets are positioned in a different sequential portion of the passage to divide that passage portion into a predetermined number of additional passages. At least one of the additional passages is smaller than at least one of the preceding passages.