Dust mobilization and transport in the northern Sahara during SAMUM 2006 – a meteorological overview

Many pharmaceutical industries all around the world are facing the problem of dust mobilization during the productive process of medicines. This mobilization can be dangerous for the safety of the operators working in the factory and for the safety of the factory itself. It is therefore necessary to develop predictive models to simulate and forecast dust mobilization. The Quantum Electronics and Plasma Physics (QEP) Research Group of the University of Rome Tor Vergata has developed a facility to experimentally replicate dust mobilization in different critical conditions in an enclosed environment. The measurements performed with diagnostics available in the facility, provide the boundary conditions to run numerical simulations and to validate mobilization models . Even if the initial field of application of this novel facility is dust mobilization is nuclear fusion, the methodology developed can be used for the medicine industry, for the agribusiness and others. The authors will present the experimental and numerical results discussing new applications.

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Response of dust emissions in southwestern North America to 21st century trends in climate, CO<sub>2</sub> fertilization, and land use: implications for air quality

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-57-2021 ◽

2021 ◽

Vol 21 (1) ◽

pp. 57-68

Author(s):

Yang Li ◽

Loretta J. Mickley ◽

Jed O. Kaplan

Keyword(s):

Land Use ◽

New Mexico ◽

Air Quality ◽

North America ◽

Human Health ◽

21St Century ◽

Fine Dust ◽

Co2 Fertilization ◽

Dust Emissions ◽

Dust Mobilization

Abstract. Climate models predict a shift toward warmer and drier environments in southwestern North America. The consequences of such a shift for dust mobilization and dust concentration are unknown, but they could have large implications for human health, given the connections between dust inhalation and disease. Here we link a dynamic vegetation model (LPJ-LMfire) to a chemical transport model (GEOS-Chem) to assess the impacts of future changes in three factors – climate, CO2 fertilization, and land use practices – on vegetation in this region. From there, we investigate the impacts of changing vegetation on dust mobilization and assess the net effect on fine dust concentration (defined as dust particles less than 2.5 µm in diameter) on surface air quality. We find that surface temperatures in southwestern North America warm by 3.3 K and precipitation decreases by nearly 40 % by 2100 in the most extreme warming scenario (RCP8.5; RCP refers to Representative Concentration Pathway) in spring (March, April, and May) – the season of greatest dust emissions. Such conditions reveal an increased vulnerability to drought and vegetation die-off. Enhanced CO2 fertilization, however, offsets the modeled effects of warming temperatures and rainfall deficit on vegetation in some areas of the southwestern US. Considering all three factors in the RCP8.5 scenario, dust concentrations decrease over Arizona and New Mexico in spring by the late 21st century due to greater CO2 fertilization and a more densely vegetated environment, which inhibits dust mobilization. Along Mexico's northern border, dust concentrations increase as a result of the intensification of anthropogenic land use. In contrast, when CO2 fertilization is not considered in the RCP8.5 scenario, vegetation cover declines significantly across most of the domain by 2100, leading to widespread increases in fine dust concentrations, especially in southeastern New Mexico (up to ∼ 2.0 µg m−3 relative to the present day) and along the border between New Mexico and Mexico (up to ∼ 2.5 µg m−3). Our results have implications for human health, especially for the health of the indigenous people who make up a large percentage of the population in this region.

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Development of a Hybrid Turbulent Particle Dispersion Model and Implementation in the Gasflow Code

Volume 4: Structural Integrity; Next Generation Systems; Safety and Security; Low Level Waste Management and Decommissioning; Near Term Deployment: Plant Designs, Licensing, Construction, Workforce and Public Acceptance ◽

10.1115/icone16-48681 ◽

2008 ◽

Author(s):

Zhanjie Xu ◽

John R. Travis ◽

Wolfgang Breitung

Keyword(s):

Dispersion Model ◽

Separated Flow ◽

Particle Dispersion ◽

Turbulent Dispersion ◽

Vacuum Vessel ◽

Dispersion Models ◽

Proposed Model ◽

Dust Mobilization ◽

Decaying Turbulence ◽

Turbulent Particle Dispersion

Dust mobilization in a vacuum vessel is one of the key issues endangering the security of the International Thermonuclear Experimental Reactor (ITER), in case of Loss of Vacuum Accidents (LOVA). The turbulent behavior of particles in turbulent flows has to be modeled for successful numerical simulations about particle mobilization. In this study a Lagrangian approach is adopted to formulate the particle transport especially for dust-dilute flows mostly encountered in the vacuum vessel of ITER. Based on the logic frame of the approach and the used Computational Fluid Dynamic (CFD) computer code in the study, a hybrid turbulent particle dispersion model is proposed. The hybrid model features both a deterministic separated flow (DSF) model and a stochastic separated flow (SSF) model, which are two popular turbulent dispersion models applied in particle simulations, and takes the advantages of the both models. The proposed model is implemented into the particle model of the CFD code successfully and the simulation results are verified against experimental data. The verifications manifest the validities of the proposed model. In this paper general information about the work of dust mobilization is introduced and the particle turbulent dispersion models are reviewed briefly at first. The hybrid model is then proposed based on the SSF model. An experiment about particle dispersions in an advective wind channel flow with decaying turbulence in the streamwise direction is reviewed in the third section. In the following section about model verification, the decaying turbulence parameters in the channel flow are verified against experimental data as the first step, the parameters about the particle dispersions in the verified flow field are then verified against the data. The work is concluded finally.

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Development of a Hybrid Turbulent Particle Dispersion Model and Implementation in the Gasflow Code

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.2983142 ◽

2008 ◽

Vol 131 (1) ◽

Author(s):

Zhanjie Xu ◽

John R. Travis ◽

Wolfgang Breitung

Keyword(s):

Dispersion Model ◽

Separated Flow ◽

Particle Dispersion ◽

Turbulent Dispersion ◽

Vacuum Vessel ◽

Dispersion Models ◽

Proposed Model ◽

Dust Mobilization ◽

Decaying Turbulence ◽

Turbulent Particle Dispersion

Dust mobilization in a vacuum vessel is one of the key issues endangering the security of the International Thermonuclear Experimental Reactor (ITER) in case of loss of vacuum accidents. The turbulent behavior of particles in turbulent flows has to be modeled for successful numerical simulations about particle mobilization. In this study a Lagrangian approach is adopted to formulate the particle transport especially for dust-dilute flows mostly encountered in the vacuum vessel of ITER. Based on the logic frame of the approach and the used computational fluid dynamics (CFD) computer code in the study, a hybrid turbulent particle dispersion model is proposed. The hybrid model features both a deterministic separated flow model and a stochastic separated flow (SSF) model, which are two popular turbulent dispersion models applied in particle simulations, and takes the advantages of the both models. The proposed model is implemented into the particle model of the CFD code successfully and the simulation results are verified against the experimental data. The verifications manifest the validities of the proposed model. In this paper general information about the work of dust mobilization is introduced and the particle turbulent dispersion models are reviewed briefly at first. The hybrid model is then proposed based on the SSF model. An experiment about particle dispersions in an advective wind channel flow with decaying turbulence in the streamwise direction is reviewed in the third section. In the following section about model verification, the decaying turbulence parameters in the channel flow are verified against the experimental data as the first step, and the parameters about the particle dispersions in the verified flow field are then verified against the data. The work is concluded finally.

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