Flow Properties of a Supersonic Turbulent Boundary Layer with Wall Roughness
Academic Article
Overview
Identity
Additional Document Info
Other
View All
Overview
abstract
An experimental study of the influence of surface roughness on the mean and turbulent flow properties of a high-speed (M = 2.9, Re/m = 2.0107) turbulent boundary layer flow was performed. Six wall topologies, including a smooth and five rough surfaces consisting of three random sand-grain plates and two uniformly machined plates (ks+ = 100-570), were tested. Mean flow measurements included surveys of the velocity and density. Turbulence quantities included direct measurements of the kinematic velocity turbulence intensities, mass flux turbulence intensities, the kinematic Reynolds shear stress, the compressible Reynolds shear stress and the density-transverse-velocity fluctuation correlation. The trends in the mean flow, observed for incompressible flow, were found to hold for the present study when Van Driest II scaling was used. Kinematic statistical turbulent flow properties were found to scale by local mean quantities. Conversely, turbulent flow statistical properties with an explicit thermodynamic dependence did not scale by local mean quantities and had a strong linear dependence on roughness height. Roughness was found to extend the region where inner scaling held toward larger values of y+ for the compressible Reynolds shear stress, the x- and y-velocity component turbulence intensities, the x-component of the mass flux turbulence intensity, and the density-transverse-velocity correlation.
