Rough Surfaces

In fluid dynamics, we’re often concerned with flow moving past a solid surface — air past an airplane wing, water past fish scales, oil between moving parts — and those surfaces are rarely perfectly smooth. Rough surfaces affect the flow near them, sometimes in unexpected ways. Here, researchers show a rough surface’s effect on the eddies of the atmospheric boundary layer. Put differently, this poster shows how buildings, trees, and other features influence the lowest layer of the atmosphere. From the tiny gaps between buildings to the eddies towering many times higher, the turbulence reflects roughness’s effects. (Image credit: J. Kostelecky and C. Ansorge)