Structured elements and methods of use

A method of distributing the flow of a fluid stream within a process unit, the method comprising:

• passing the fluid stream through a plurality of structured elements in the process unit, each structured element comprising one or more interconnected unit cells, each unit cell having a frame with a three-dimensional polyhedron structure and a plurality of faces, wherein the faces include a combination of open faces, partially open faces and closed faces, and wherein the frame, the partially open faces and the closed faces each have a plurality of differently-shaped asperities disposed on the surfaces thereof;
• and
• contacting the fluid stream with the structured elements as the fluid stream flows through the structured elements, such that the fluid steam is subdivided into substreams.