PERSPECTIVE - ON THE NEAR WALL SIMILARITY OF 3-DIMENSIONAL TURBULENT BOUNDARY-LAYERS

The possible existence of a ''law-of-the-wall'' similarity velocity profile for 3-D boundary layers was investigated using nine different proposed relations with the data from nine experiments carried out in 3-D turbulent boundary layers. Both for pressure driven and shear-driven flows, the ''law-of-the-wall'' relation of Johnston for the local freestream velocity direction component best applies. Although not well described by any relation, the crosswise velocity component of pressure-driven flows and shear-driven flows is best represented by Mager's relation and Chandrashekhar and Swamy equation, respectively.