Measurements of turbulence moments in boundary layers over transversely grooved surfacesWind tunnel measurements of second, third, and fourth order turbulence moments in turbulent boundary layers over d-types and k-types of grooved and smooth surfaces are discussed. The near-wall turbulence structure is found to vary with the spanwise aspect ratio. For decreasing height, the third moment of the normal velocity fluctuations is shown to become negative over crop canopies and model plant canopies, although not in smooth, two-dimensional, sandgrain or gravel roughness. The instantaneous motions related to the flux of shear stress near the wall in smooth and transversely grooved surfaces are shown to be opposite in sign to those in three-dimensional roughness.
Document ID
19880026900
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Bandyopadhyay, P. R. (NASA Langley Research Center Hampton, VA, United States)
Watson, R. D. (NASA Langley Research Center Hampton, VA, United States)