2D Particle Transport in a Full Dilution Tunnel of Diesel Vehicle Emissions

Current EU legislation establishes particulate-mass emission limits for diesel vehicles, but limits on particle number emissions are also under consideration due to concerns about the adverse health effects of fine particles. We study the turbulent transport of light-duty diesel exhaust particles in a standard emission facility.JRC.H.4-Transport and air qualit

Individual mobility: From conventional to electric cars

The aim of this report is twofold. First, to analyse individual (driver) mobility data to obtain fundamental statistical parameters of driving patterns for both conventional and electric vehicles. In doing so, the information contained in large mobility datasets is condensed into compact and concise descriptions through modelling observed (experimental) distributions of mobility variables by expected theoretical distributions. Specifically, the stretched exponential distribution is shown to model rather accurately the distribution of single-trips and their duration, and the scale-invariant power-law with exponential cut-off the daily mobility length, the distance travelled per day. We argue that the theoretical-distribution parameters depend on the road-network topology, terrain topography, traffic, points of interest, and individual activities. Data from conventional vehicles suggest three approximate daily driving patterns corresponding to weekday, Saturday and Sunday driving, the latter two being rather similar. Work trips were found to be longer than average and of longer duration. The second aim is to ascertain, via the limited electric-vehicle data available from the EU-funded Green eMotion project, whether the behaviour of drivers of conventional vehicles differs from the behaviour of drivers of electric vehicles. The data suggest that electric vehicles are driven for shorter distances and shorter duration. Data from the Green eMotion project showed that the median real-life energy consumption of a typical segment A, small-sized, electric car, for example the Mitsubishi i-MiEV and its variants, is 186 Wh/km with a spread of 55 Wh/km. The real-driving energy consumption (per km) was determined to be approximately 38% higher than the type-approved consumption. Moreover, we found considerable dependence of the energy consumed on the ambient temperature. The median winter energy consumption per kilometre was higher than the median summer consumption by approximately 40%. The data presented in this report can be fundamental for subsequent analyses of infrastructure requirements for electric vehicles and assessments of their potential contribution to energy, transport, and climate policy objectives.JRC.F.8-Sustainable Transpor

The Friction Coefficient of Fractal Aggregates in the Continuum and Transition Regimes

A methodology is introduced for friction-coefficient calculations of fractal-like aggregates that relates the friction coefficient to a solution of the diffusion equation. Synthetic fractal aggregates were created with a cluster-cluster aggregation algorithm. Their fiction coefficients were obtained from gas molecule-aggregate collision rates that were calculated with the COMSOL Multiphysics software. Results were compared and validated with literature values. The effect of aggregate structure on dynamical properties of the aggregate, in particular mobility, was also studied. Both the fractal dimension and the fractal prefactor are required to characterize fully an aggregate.JRC.F.8-Sustainable Transpor

Data Collection and Reporting Guidelines for European electro-mobility projects

Analysis of the data collected from electro-mobility projects has shown that only in very limited cases, the data reported were of enough quality and/or comprehensive enough to allow a meaningful and complete analysis. Various types of data are sometimes missing, making it almost impossible to analyse them correctly. The objective of this report is to provide guidance to publicly funded European Electro-mobility Projects on what and how to monitor and report. Detailed description of the necessary monitored elements and those which are considered as optional due to the complexity or expense involved in collecting them, is included, as well some ideas on quality control and on data collection. An extensive stakeholder consultation has taken place before the release of this report.JRC.F.6-Energy Technology Policy Outloo

Theoretical Investigation of Volatile Removal Efficiency of Particle Number Measurement Systems

Euro 5/6 light-duty vehicle emissions regulation introduced non-volatile particle number emission measurements. The particle number measurement system consists of a volatile removal unit followed by a particle number counter with a 50% cut-point diameter at 23 nm. The volatile removal unit must achieve a >99% concentration reduction of a monodisperse aerosol of tetracontane (CH3(CH2)38CH3) particles of diameter =30 nm with inlet concentration =104 cm-3. In this paper the evaporation of tetracontane particles in the volatile removal unit is investigated theoretically. The temperature and the residence time in the evaporation tube are discussed, as well as the possibility of nucleation events of evaporated particles at the exit of the evaporation tube. In addition, sulfuric acid nucleation at the evaporation tube exit is analyzed. Theoretical calculations are, finally, compared to experimental data. Our main conclusion is that the volatile removal efficiency requirements of the legislation can be easily met. However, as some experimental measurements showed, the removal efficiency might differ for large particle sizes and high concentrations; thus, the results of particle number counters with a 50% cut-point diameter less than 23 nm should be interpreted with care.JRC.DDG.H.4-Transport and air qualit

Resuspension of Small Particles by Turbulent Flow

Abstract not availableJRC.(STI)-Institute For Safety Technolog

Aerosol Dynamics

Airborne particulate matter (PM) contains different chemical components, its size ranging from few nanometers to several hundred micrometers (Hinds, 1999). It is apparent that particulate matter is not a single pollutant, and its mass includes a mixture of numerous pollutants distributed differently at different sizes. Particle size is an essential parameter that determines the chemical composition, optical properties, deposition of particles, and their inhalation in the human respiratory tract (Hinds, 1999; Friedlander, 2000; Seinfeld and Pandis, 2006; Lazaridis, 2011). Particle size is specified by the particle diameter, , which is most commonly expressed in micrometers. Particles represent a very small fraction, less than 0.0001%, of the total aerosol mass or volume (Drossinos and Housiadas, 2005). The gas phase influences mainly the particle flow through hydrodynamic forces.JRC.F.6-Energy systems evaluatio

Time Evolution of the Aggregate Fractal Dimension from Langevin Dynamics

Combustion-generated solid nanoparticles are often fractal-like aggregates (clusters) of smaller units taken to be spherical primary particles, monomers. The aggregate mass exhibits a power-law dependence on a characteristic size, usually identified with the radius of gyration. The power-law exponent is the aggregate fractal dimension. We investigate the non-equilibrium Brownian particle dynamics by solving the Langevin equations for a system of interacting aggregates in three dimensions. Our objective is to study the time evolution of the aggregate fractal dimension as an indicator of the varying aggregate morphology.JRC.H.4-Transport and air qualit

Calculation of Aggregate Friction Coefficient From Active Surface

The hydrodynamic behaviour of fractal-like soot aggregates suspended in a viscous fluid is of considerable importance for their transport and depositional properties. The calculation of the drag force on a fractal aggregate consisting of primary spherules, henceforth called monomers, involves solving numerically Stokes equation for a low Reynolds number steady flow past the aggregate (Filippov, 2000). Analytical treatments usually require simplifying assumptions like aggregate spherical symmetry.JRC.DDG.H.4-Transport and air qualit

Aerosol flows

See attached documentJRC.H.4-Transport and air qualit