The development of three-dimensional wall jet

Detailed flow field measurements were performed in the near and intermediate field of the three-dimensional wall jet exiting a round jet. It was found that the profiles of the mean streamwise and lateral velocity are approximately self-similar in the region 25less than or equal tox/Dless than or equal to40. The profiles of the turbulent Reynolds stresses required longer to become self-similar, as expected, but seem to be self-similar by x/Dapproximate to40: The mean streamwise vorticity contours on cross-stream planes in the wall jet also changed until x/Dapproximate to40 indicating that the large-scale structures that contribute to these measurements are still evolving to this Point in the flow. The change in the orientation of the two regions of counter rotating vorticity on each side of the jet centreline in the region 15less than or equal tox/Dless than or equal to40can be used to explain the change in the jets lateral growth rate observed in this region.