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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Turbulent dispersion in cloud-topped boundary layers
TL;DR: In this paper, the dispersion of a passive tracer in the form of Lagrangian particles for four kinds of atmospheric boundary layers: 1) a dry convective boundary layer (for reference), 2) a "smoke" cloud boundary layer in which the turbulence is driven by radiative cooling, 3) a stratocumulus topped boundary layer and 4) a shallow cumulus capped boundary layer.
Journal ArticleDOI
Inverse dispersion modelling highlights the efficiency of slurry injection to reduce ammonia losses by agriculture in the Po Valley (Italy)
TL;DR: In this article, the performance of two inverse dispersion models to quantify ammonia fluxes has been evaluated using a sonic anemometer to characterise the atmospehric turbulence and provided the necessary inputs for the inverse models.
Journal ArticleDOI
CTBT radioxenon monitoring for verification: today’s challenges
TL;DR: New methodologies for backtracking nuclide detections improved the capability to locate sources and corroborate the role of radioxenon monitoring, and the importance of atmospheric transport modelling is demonstrated both for completely understanding the civilian background and for explaining peak concentrations and abnormal events.
Journal ArticleDOI
Fluid particle dispersion in homogeneous turbulent shear flow
Peiqing Shen,P. K. Yeung +1 more
TL;DR: In this article, the dispersion of Lagrangian fluid particle pairs in homogeneous turbulent shear flow is studied by a direct numerical simulation using 256×1282 grid points, and the effects of initial particle positions and pair separation on displacement and dispersion statistics are examined in relation to classical theory.
Journal ArticleDOI
Prediction of Extrathoracic Aerosol Deposition using RANS-Random Walk and LES Approaches
TL;DR: In this paper, the RANS-RSM model is used to obtain the mean carrier flow field, whereas turbulent fluid velocities are defined through a stochastic continuous random walk (CRW) model based on the normalized Langevin equation.
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.