NEAR-WALL FLOW IN A 3-DIMENSIONAL BOUNDARY-LAYER ON THE ENDWALL OF A 30-DEGREES BEND

Turbulence measurements are reported on the three-dimensional turbulen t boundary layer along the centerline of the flat endwall in a 30 degr ees bend. Profiles of mean velocities and Reynolds stresses were obtai ned down to y(+) approximate to 2 for the mean flow and y(+) approxima te to 8 for the turbulent stresses. Mean velocity data collapsed well on a simple law-of-the-wall based on the magnitude of the resultant ve locity. The turbulence intensity and turbulent shear stress magnitude both increased with increased three-dimensionality. The ratio of these two quantities, the a(1) structure parameter, decreased in the centra l regions of the boundary layer and showed profile similarity for y(+) < 50. The shear stress vector angle lagged behind the velocity gradie nt vector angle in the outer region of the boundary layer, however the re was an indication that the shear stress vector tends to lead the ve locity gradient vector close to the wall.