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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Journal ArticleDOI
Relationship between the Vertical Velocity Skewness and Kurtosis Observed during Sea-Breeze Convection
TL;DR: In this paper, sound detection and ranging (sodar) measurements in well-developed, almost steady convective conditions are selected and analyzed to investigate the relationship between skewness and kurtosis.
Journal ArticleDOI
The influence of an anisotropic Langevin dispersion model on the prediction of micro- and nanoparticle deposition in wall-bounded turbulent flows
TL;DR: In this article, a simple method is proposed to implement a three-dimensional stochastic dispersion model based on the Langevin equation in the Fluent ® commercial code, complemented by the simulation of Brownian effects and available numerical data obtained using either an eddy lifetime model or a simple Langevin model.
Journal ArticleDOI
Stochastic Models for the Kinematics of Moisture Transport and Condensation in Homogeneous Turbulent Flows
Paul A. O'Gorman,Tapio Schneider +1 more
TL;DR: In this paper, a one-dimensional stochastic model was developed in which the Lagrangian velocities of air parcels are independent Ornstein-Uhlenbeck (Gaussian colored noise) processes.
Journal ArticleDOI
Lagrangian modelling of plankton motion: From deceptively simple random walks to Fokker–Planck and back again
TL;DR: In this article, the movement of plankton, either by turbulent mixing or their own inherent motility, can be simulated in a Lagrangian framework as a random walk, which leads to radically different macroscale dynamics as expressed in their corresponding Fokker-Planck equations.
Journal ArticleDOI
Lagrangian Stochastic Modelling of Dispersion in the Convective Boundary Layer with Skewed Turbulence Conditions and a Vertical Density Gradient: Formulation and Implementation in the FLEXPART Model
TL;DR: In this article, a correction for the vertical gradient of air density has been incorporated into a skewed probability density function formulation for turbulence in the convective boundary layer, and a related drift term for Lagrangian stochastic dispersion modelling has been derived based on the well-mixed condition.
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.