Journal ArticleDOI
Criteria for the selection of stochastic models of particle trajectories in turbulent flows
TLDR
In this paper, the relationships between the various criteria are examined for a very general class of models and it is shown that most of the criteria are equivalent and also how a model can be designed to satisfy these criteria exactly and to be consistent with inertial-subrange theory.Abstract:
Many different random-walk models of dispersion in inhomogeneous or unsteady turbulence have been proposed and several criteria have emerged to distinguish good models from bad. In this paper the relationships between the various criteria are examined for a very general class of models and it is shown that most of the criteria are equivalent. It is also shown how a model can be designed to satisfy these criteria exactly and to be consistent with inertial-subrange theory. Some examples of models that obey the criteria are described. As an illustration some calculations of dispersion in free-convective conditions are presented.read more
Citations
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Modelling the dispersion of aerial pollutants from agricultural buildings — an evaluation of computational fluid dynamics (CFD)
TL;DR: In this paper, the authors explored some of the computational modelling methods available to predict near field concentrations of a pollutant emitted from a building opening. But the modelling approaches used here are restricted in application to effectively weightless particles, such as a low concentration pollutant gas.
Journal ArticleDOI
Micromixing modelling of concentration fluctuations in inhomogeneous turbulence in the convective boundary layer
TL;DR: In this article, a model based on the interaction-by-exchange-with-the-conditional-mean (IECM) approach is formulated to calculate concentration fluctuation statistics for a line source and a point source in inhomogeneous and non-Gaussian turbulence in the convective boundary layer.
Journal ArticleDOI
Determination of the coefficients of Langevin models for inhomogeneous turbulent flows by three-dimensional particle tracking velocimetry and direct numerical simulation
TL;DR: In this article, a direct numerical simulation (DNS) code has been developed and experimental results have been compared with results of this DNS code, based on these, coefficients of the Langevin model have been determined and physical consequences for Langevin modeling and turbulent dispersion have been explained.
Journal ArticleDOI
Large-eddy simulation and Lagrangian stochastic modeling of passive scalar dispersion in a turbulent boundary layer
TL;DR: In this article, a large-eddy simulation with the dynamic Smagorinsky-Germano subgrid scale (SGS) model is used to study the passive scalar dispersion in a turbulent boundary layer.
Journal ArticleDOI
Geometry and violent events in turbulent pair dispersion
TL;DR: In this paper, the statistics of Lagrangian pair dispersion in a homogeneous isotropic flow are investigated by means of direct numerical simulations, where the focus is on deviations from the Richardson eddy-diffusivity model and in particular on the strong fluctuations experienced by tracers.
References
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Journal ArticleDOI
An Introduction to Probability Theory and Its Applications.
Journal ArticleDOI
Turbulence Structure in the Convective Boundary Layer
TL;DR: In this paper, a boundary layer experiment conducted over a flat site in northwestern Minnesota is discussed, where wind and temperature fluctuations near the ground were measured with AFCRL's fast-response instrumentation on a 32 m tower with MRU probes attached at five different heights to the tethering cable of a 1300 m2 kite balloon.
Book
Theory and Applications of Stochastic Differential Equations
Zeev Schuss,Robert O'Malley +1 more
TL;DR: Presents theory, sources, and applications of stochastic differential equations of Ito's type; those containing white noise; and the role of partial differential equations in this context.