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Estimate of vegetation efficiency on reducing dust concentration produced by a surface coal mine

Řezníček, Hynek, Beneš, Luděk (2019)

Programs and Algorithms of Numerical Mathematics

A new vegetative barrier can help to reduce dust concentration in a surface coal mine neighbourhood. The project reports about quantification of this effect. An air flow field is computed together with the dust transport driven by it using an in-house CFD solver. The 2D cuts of a real geometry of Bílina coal mine in north Bohemia are used. The vegetation is modelled as horizontally homogeneous porous medium which slows the air flow inside. An influence on turbulence and filtering the dust particles...

Estimates based on scale separation for geophysical flows.

François Jauberteau, Roger Temam (2002)

RACSAM

The objective of this work is to obtain theoretical estimates on the large and small scales for geophysical flows. Firstly, we consider the shallow water problem in the one-dimensional case, then in the two-dimensional case. Finally we consider geophysical flows under the hydrostatic hypothesis and the Boussinesq approximation. Scale separation is based on Fourier series, with N models in each spatial direction, and the choice of a cut-off level N1 < N to define large and small scales. We...

Fast Singular Oscillating Limits and Global Regularity for the 3D Primitive Equations of Geophysics

Anatoli Babin, Alex Mahalov, Basil Nicolaenko (2010)

ESAIM: Mathematical Modelling and Numerical Analysis

Fast singular oscillating limits of the three-dimensional "primitive" equations of geophysical fluid flows are analyzed. We prove existence on infinite time intervals of regular solutions to the 3D "primitive" Navier-Stokes equations for strong stratification (large stratification parameter N). This uniform existence is proven for periodic or stress-free boundary conditions for all domain aspect ratios, including the case of three wave resonances which yield nonlinear " 2 1 2 dimensional" limit equations...

Heavy tailed durations of regional rainfall

Harry Pavlopoulos, Jan Picek, Jana Jurečková (2008)

Applications of Mathematics

Durations of rain events and drought events over a given region provide important information about the water resources of the region. Of particular interest is the shape of upper tails of the probability distributions of such durations. Recent research suggests that the underlying probability distributions of such durations have heavy tails of hyperbolic type, across a wide range of spatial scales from 2 km to 120 km. These findings are based on radar measurements of spatially averaged rain rate...

Mathematical Modeling of Atmospheric Flow and Computation of Convex Envelopes

A. Caboussat (2011)

Mathematical Modelling of Natural Phenomena

Atmospheric flow equations govern the time evolution of chemical concentrations in the atmosphere. When considering gas and particle phases, the underlying partial differential equations involve advection and diffusion operators, coagulation effects, and evaporation and condensation phenomena between the aerosol particles and the gas phase. Operator splitting techniques are generally used in global air quality models. When considering organic aerosol...

Multiple spatial scales in engineering and atmospheric low Mach number flows

Rupert Klein (2005)

ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique

The first part of this paper reviews the single time scale/multiple length scale low Mach number asymptotic analysis by Klein (1995, 2004). This theory explicitly reveals the interaction of small scale, quasi-incompressible variable density flows with long wave linear acoustic modes through baroclinic vorticity generation and asymptotic accumulation of large scale energy fluxes. The theory is motivated by examples from thermoacoustics and combustion. In an almost obvious way specializations of this...

Multiple spatial scales in engineering and atmospheric low Mach number flows

Rupert Klein (2010)

ESAIM: Mathematical Modelling and Numerical Analysis

The first part of this paper reviews the single time scale/multiple length scale low Mach number asymptotic analysis by Klein (1995, 2004). This theory explicitly reveals the interaction of small scale, quasi-incompressible variable density flows with long wave linear acoustic modes through baroclinic vorticity generation and asymptotic accumulation of large scale energy fluxes. The theory is motivated by examples from thermoacoustics and combustion. In an almost obvious way specializations of...

Currently displaying 21 – 40 of 53