Showing papers by "National Waste & Recycling Association published in 2001"
TL;DR: In this paper, the dynamics and turbulent evolution of a stratified shear layer are explored through direct numerical simulation, and large and small-scale anisotropy are examined by comparing spectra for the longitudinal and transverse correlation coefficients, RMS velocity components and velocity and temperature derivatives during the time when turbulence is most intense.
Abstract: The dynamics and turbulent evolution of a stratified shear layer are explored through direct numerical simulation. Turbulence is instigated through the most unstable asymptotic linear Kelvin-Helmholtz (KH) eigenmode at Richardson number Ri = 0.05 and Reynolds number Re = 2000 (Ri and Re are defined below). The primary 2D KH vortex succumbs to 3D motions in a manner consistent with earlier findings. The shear-layer Reynolds number ReL (defined below) grows to ReL ≈ 2.4 × 104 as the layer expands and small length-scale motions develop. Large- and small-scale anisotropy are examined by comparing 1) spectra for the longitudinal and transverse correlation coefficients, 2) RMS velocity components and 3) velocity and temperature derivatives during the time when turbulence is most intense. The mean shear produces a tendency toward streamwise axisymmetric, as opposed to isotropic, turbulent flow; however, departures from streamwise axisymmetry due to stratification are evident in the dissipation fields (i.e., at small scales).
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