PAHs in the Fraser River basin: a critical appraisal of PAH ratios as indicators of PAH source and composition

Engines and nanoparticles: a review

Evaluation of sediment contamination by polycyclic aromatic hydrocarbons in the Gironde estuary

https://research.birmingham.ac.uk/portal/files/11961623/Estimation_of_the_Contribution_of_Road_Traffic_Emissions_V3_PostPrint.pdf

Estimation of the contribution of road traffic emissions to particulate matter concentrations from field measurements: A review

The development of four-stroke, spark-ignition engines that are designed to inject gasoline directly into the combustion chamber is an important worldwide initiative of the automotive industry. The thermodynamic potential of such engines for significantly enhanced fuel economy, transient response and cold-start hydrocarbon emission levels has led to a large number of research and development projects that have the goal of understanding, developing and optimizing gasoline direct-injection (GDI) combustion systems. The processes of fuel injection, spray atomization and vaporization, charge cooling, mixture preparation and the control of in-cylinder air motion are all being actively researched, and this work is reviewed in detail and analyzed. The new technologies such as high-pressure, common-rail, gasoline injection systems and swirl-atomizing gasoline fuel injectors are discussed in detail, as these technologies, along with computer control capabilities, have enabled the current new examination of an old objective; the direct-injection, stratified-charge (DISC), gasoline engine. The prior work on DISC engines that is relevant to current GDI engine development is also reviewed and discussed.

The fuel economy and emission data for actual engine configurations are of significant importance to engine researchers and developers. These data have been obtained and assembled for all of the available GDI literature, and are reviewed and discussed in detail. The types of GDI engines are arranged in four classifications of decreasing complexity, and the advantages and disadvantages of each class are noted and explained. Emphasis is placed upon consensus trends and conclusions that are evident when taken as a whole. Thus the GDI researcher is informed regarding the degree to which engine volumetric efficiency and compression ratio can be increased under optimized conditions, and as to the extent to which unburned hydrocarbon (UBHC), NOx and particulate emissions can be minimized for specific combustion strategies. The critical area of GDI fuel injector deposits and the associated effect on spray geometry and engine performance degradation are reviewed, and important system guidelines for minimizing deposition rates and deposit effects are presented. The capabilities and limitations of emission control techniques and aftertreatment hardware are reviewed in depth, and areas of consensus on attaining European, Japanese and North American emission standards are compiled and discussed.

All known research, prototype and production GDI engines worldwide are reviewed as to performance, emissions and fuel economy advantages, and for areas requiring further development. The engine schematics, control diagrams and specifications are compiled, and the emission control strategies are illustrated and discussed. The influence of lean-NOx catalysts on the development of late-injection, stratified-charge GDI engines is reviewed, and the relative merits of lean-burn, homogeneous, direct-injection engines as an option requiring less control complexity are analyzed. All current information in the literature is used as the basis for discussing the future development of automotive GDI engines.

Automotive Spark-Ignited Direct-Injection Gasoline Engines

The relation between polycyclic aromatic compounds in diesel fuels and exhaust particulates

Diesel particulate emissions: The role of unburned fuel

Determination of burning velocity by double ignition in a closed vessel

Traffic-related emissions represent a major component of airborne pollution. Historically, dynamometer testing has been most widely used to estimate vehicle emission rates, and these emission rates, in turn, have been used as inputs when modeling traffic-related air quality impacts. However, such conventional drive cycle testing is not considered strictly representative of vehicles under real driving conditions. Therefore, in recent years, significant scientific effort has been focused on the measurement and analysis of real-world vehicle emissions. Here, the use of vehicle emissions monitoring methods (e.g., in-situ methods such as tunnel, inverse dispersion, and remote sensing studies, and in-traffic measures such as probe vehicle and “car chaser” studies) to provide real-world emission estimates is reviewed and discussed in detail. Advantages and disadvantages are identified for the different vehicle emissions monitoring methods, both relative to dynamometer-based approaches and each other. Potential a...

Real-World Vehicle Exhaust Emissions Monitoring. Review and Critical Discussion

A typical building consists of a number of rooms; often with windows of different size and failure pressure and obstructions in the form of furniture and decor, separated by partition walls with interconnecting doorways. Consequently, the maximum pressure developed in a gas explosion would be dependent upon the individual characteristics of the building. In this research, a large-scale experimental programme has been undertaken at the DNV GL Spadeadam Test Site to determine the effects of vent size and congestion on vented gas explosions. Thirty-eight stoichiometric natural gas/air explosions were carried out in a 182 m 3 explosion chamber of L/D = 2 and K A  = 1, 2, 4 and 9. Congestion was varied by placing a number of 180 mm diameter polyethylene pipes within the explosion chamber, providing a volume congestion between 0 and 5% and cross-sectional area blockages ranging between 0 and 40%. The series of tests produced peak explosion overpressures of between 70 mbar and 3.7 bar with corresponding maximum flame speeds in the range 35–395 m/s at a distance of 7 m from the ignition point. The experiments demonstrated that it is possible to generate overpressures greater than 200 mbar with volume blockages of as little as 0.57%, if there is not sufficient outflow through the inadvertent venting process. The size and failure pressure of potential vent openings, and the degree of congestion within a building, are key factors in whether or not a building will sustain structural damage following a gas explosion. Given that the average volume blockage in a room in a UK inhabited building is in the order of 17%, it is clear that without the use of large windows of low failure pressure, buildings will continue to be susceptible to significant structural damage during an accidental gas explosion.

Gordon E. Andrews

Papers

The relation between polycyclic aromatic compounds in diesel fuels and exhaust particulates

Diesel particulate emissions: The role of unburned fuel

Determination of burning velocity by double ignition in a closed vessel

Real-World Vehicle Exhaust Emissions Monitoring. Review and Critical Discussion

The effect of vent size and congestion in large-scale vented natural gas/air explosions