Investigation of the diffusion in turbulent shear flow
Abstract
Corrsin's Independence Hypothesis (1959) in statistical turbulence theory as applied to homogeneous uniform flow is discussed, and the hypothesis is extended to a flow with uniform shear gradient. This problem has intrinsic importance in the study of diffusion of pollutants in the lower atmosphere surface layer. By use the Eulerian space-time correlation data measured in the atmospheric surface layer under unstable conditions, parameters for the extended hypotheses are obtained. A diffusion model for this turbulent shear flow is proposed, based on the concept of turbulent diffusivities and the dispersion tensor. A set of equations is obtained for the diffusivity tensor and dispersion tensor in terms of the statistical correlation tensors of the Lagrangian velocity field. The solutions of these equations together with the diffusion equations can be expressed as a multinormal distribution function using the initial condition of instantaneous point source.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1977
- Bibcode:
- 1977PhDT........87H
- Keywords:
-
- Atmospheres;
- Contaminants;
- Diffusion;
- Shear Flow;
- Turbulence;
- Atmospheric Models;
- Euler Equations Of Motion;
- Lower Atmosphere;
- Fluid Mechanics and Heat Transfer