Download or read book Modeling the Evolution of Vehicle Exhaust Plume Near Road and in Laboratory Dilution Systems Using the CTAG Model written by Yan Wang and published by . This book was released on 2013 with total page 209 pages. Available in PDF, EPUB and Kindle. Book excerpt: There are a growing number of people living or spending substantial time near major roadways, being exposed to elevated traffic-related pollutants. Due to their adverse health effect, it is imperative to reduce the uncertainties in the traffic emission inventory and characterize the spatial and temporal impacts of pollutants on near-road air quality, which is critical to assessing human exposure. This dissertation presents the development and applications of an environmental turbulent reacting flow model, the Comprehensive Turbulent Aerosol Dynamics and Gas Chemistry (CTAG) model. CTAG is designed to simulate the transport and transformation of multiple air pollutants in various environments. For near-road applications, CTAG couples the major turbulent mixing processes with gas-phase chemistry and aerosol dynamics. CTAG demonstrates that significant improvement in predicting the spatial gradients of pollutants near roadways can be achieved by detailed treatment of turbulence characteristics. It is commonly assumed that the NO2/NOx ratio by volume for most roadways is 5%. However, this dissertation is the first to show that this assumption may not be suitable for most roadways, especially those with a high fraction of heavy-duty truck traffic. It also illustrates that the dynamics of exhaust plumes are highly sensitive to vehicle-induced turbulence, sulfuric acid induced nucleation, and condensation of organic compounds. It simulates, for the first time, the multi-scale aerosol dynamics and microenvironmental air quality by introducing a multi-scale structure to generate the processed on-road particle emissions. It implies that roadway and surrounding infrastructure designs can affect near-road air quality. CTAG can be used to improve the regulatory model in assessing the air quality in near-road environments. The turbulent reacting flows inside the fabricated dilution systems are also investigated since they are essential to most emission testing procedures and share the same mechanisms with the atmospheric dilution. CTAG investigates the effects of the dilution parameters and illustrates that turbulence plays a crucial role in mixing the exhaust with the dilution air, and the strength of nucleation dominates the level of particle emissions. A potential unifying parameter, the dilution rate of exhaust, is found to play an important role in new particle formation. Using the CTAG model, urban planners have the potential to develop strategies to reduce the uncertainties associated with dilution samplings and define a standardized dilution sampling methodology for characterizing emissions from multiple combustion sources.

Download or read book Modelling of Vehicle Exhaust Plumes Using Lattice Gas Methods written by R. D. Kingdon and published by . This book was released on 1991 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modelling of Vehicle Exhaust Plume Using Lattice Gas Methods a Feasibility Study written by R. D. Kingdom and published by . This book was released on 1991 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modelling Urban Vehicle Emissions written by M. Khare and published by Computational Mechanics. This book was released on 2001 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vehicular air pollution poses the main threat to urban air quality and is therefore one of the major components of urban air quality studies. Air quality models can play an effective role in the efficient management of such pollution.

Download or read book Fundamentals of Environmental Discharge Modeling written by Lorin R. Davis and published by CRC Press. This book was released on 2018-05-04 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book examines engineering and mathematical models for documenting and approving mechanical and environmental discharges. The author emphasizes engineering design considerations as well as applications to waste water and atmospheric discharges. Chapters discuss: the fundamentals of turbulent jet mixing, dilution concepts, and mixing zone concepts diffuser configurations and head loss calculations different modeling techniques and accepted models - discussed in detail with theoretical background, restrictions, input, output, and examples Lagrangian and the EPA UM 2-dimensional diffuser model the PLUMES interface Eulerian integral methods, EPA UDKHG 3-dimensional diffuser model, and PDSG surface discharge model empirical techniques, RSB diffuser model, the CORMIX family of models for both diffusers and surface discharge numerical methods with a discussion of shelf commercial models Gaussian atmospheric plume models Fundamentals of Environmental Discharge Modeling includes numerous case studies and examples for each model and problem.

Download or read book Automobile Exhaust Emission Testing written by H. Klingenberg and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: Differing legislation between the countries or unions of countries involved in pollution reduction has turned gas measuring technology into such an extremely extensive and complex field that only a few specialists in environmental agencies and the automobile industry have a grasp of it. This book is intended as an overview of the basics of exhaust gas measuring technology describing the interrelation between emissions, immissions and the effects of pollutants. It aims to provide experts and students alike with an understanding of the interrelationships and details within this field. The results presented are based on the experience gathered by the author during work spanning more than two decades in the automobile industry.

Download or read book Emission Control Modeling written by and published by . This book was released on 2001 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: Collection of papers from the 2001 SAE World Congress, held March 5-8 in Detroit, Michigan. Papers cover a range of computer modeling applications to emissions systems design. Topics covered include heat management, fluid flow modeling (1D as well as 3D), durability analysis, muffler and catalyst performance, and integration of emission systems to engine performance and control. Paper topics are: microkinetics modeling of catalytic converters; on a model-based control of a three-way catalytic converter; an integrated powertrain (IPT) model - stage 2, systems integration, supervisory control and simulation of emissions control technology; 1D unsteady flows with chemical reactions in the exhaust duct-system of SI engines - predictions and experiments; a modular numerical simulation tool predicting catalytic converter light-off by improved modeling of thermal management and conversion characteristics; the solution for steady state temperature distribution in monolithic catalytic converters; optimum gas design and durability analysis of catalytic converter assembly; numerical analysis of the exhaust gas flow and heat transfer in a close-coupled catalytic converter system during warm-up; and three-dimensional numerical study on the pulsating flow inside an automotive muffler with complicated flow path.

Download or read book Measurements Within the Exhaust Plume of a Passenger Car Under Real atmospheric Dilution and On road Driving Conditions written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Exhaust Systems Models Investigation by Theoretical Group Methods written by Jörg Volkmann and published by Cuvillier Verlag. This book was released on 2007 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurements Within the Exhaust Plume of a Passenger Car Under Real atmospheric Dilution and On road Driving Conditions written by Sibylle von Löwis of Menar and published by . This book was released on 2007 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Microscopic Vehicle Emission Modelling written by Hajar Hajmohammadi Hosseinabadi and published by . This book was released on 2019 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vehicle emission models are widely used to estimate air pollution from road transport. This estimation can then be considered for transport management and traffic control policies, to quantify their impacts on urban air quality. The focus of this study is to investigate the relationship between vehicle dynamics and tailpipe emission by statistical methods. These methods are: log- polynomial and classified log-polynomial model based on acceleration and deceleration, lagged regression and transfer function model based on time series analysis, gear-based emission model based on estimated transmission gear components, and the general additive model for location, scale and shape (GAMLSS) based on spline functions. The dataset for this study is second-by-second emission laboratory measurements of four different vehicle types while following a driving cycle recorded in urban, suburban and motorway areas of London. The vehicles can be categorized by size (compact and saloon), fuel type (petrol and diesel) and transmission type (manual and automatic). For each vehicle type, CO2, CO and NOx emissions are estimated in each second of driving by the speed profile as the main explanatory variable. The six emission models developed in this study are: Log-polynomial (LP), classified log-polynomial (CLP), lagged regression (LR), transfer function (TF), gear-based and GAMLSS. These are evaluated using the BIC, total emission recovery and statistical time series analysis of the residuals. The GAMLSS model consistently has the best BIC values for all vehicle and emission types, while the recovery ratio of this model is within 1% for all vehicle types. In addition, statistical analysis of the ACF/PACF time series plots shows that the GAMLSS emission model is clearer from the significant lags compared to the parametric models (LP, TF, Gear-based, gear-based and CLP). Among the parametric models, the classified models represent the emission relationship better than others. The best BIC values (after GAMLSS) were achieved by the gear- based and the CLP emission models. These results indicate that the GAMLSS approach which uses spline functions and flexible error structure performs better than the other models investigated here. This model is validated by 10- fold cross-validation approach which shows that the prediction power of the GAMLSS emission model exceeds that of the parametric models. The models are evaluated by the BIC values, total emission recovery and analysis of the residuals. Based on these criteria, the GAMLSS emission model is the most effective, especially for CO and NOx emission modelling. This model is then validated by the K-fold cross-validation process. The suggestion for future research is to evaluate the performance of the developed models with track and real driving emission (RDE) tests. The calibrated model then will be implemented to a traffic microsimulation, where different transportation management and traffic policies can be simulated and evaluated by their impacts on air quality.

Download or read book Exhaust Emission from Cars in Service written by D. M. Colwill and published by . This book was released on 1985 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Air Quality Impacts of Vehicle Emissions on the Urban Environment written by Jonathan M. Wang and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Human exposure to vehicle emissions and traffic-related air pollution is a major concern with the increasing population living near major roadways and in urban areas. Although there has been a growing interest in near-road measurements and deployment of near-road monitoring networks, isolating and quantifying vehicle emissions from these measurements have always been a challenge. Emission factors has proven to be a method that is invaluable in targeting vehicle emissions while normalizing for the effects of local dilution and dispersion. Algorithms were developed to automatically capture and calculate emission factors from exhaust plumes from vehicles. The individual plume emission factor method utilized high time resolution measurements and provided insight on inter-fleet emission dynamics and trends, providing mean emission factors for the downtown Toronto on-road fleet, co-emitted pollutants from various emitter groups, relative contributions from heavy emitters, and compared well with real-world emission factors from past studies. Additionally, discrepancies were observed between past laboratory and the measured real-world emission factors, with differences upwards of an order of magnitude for the more dynamic pollutants such as particle number concentration. Temporal variation in emission factors were also observed diurnally, weekday vs. weekend, and seasonally, where influences were found to be from changes in fleet make-up, fuel composition, and ambient conditions. A simplified daily-integrated emission factor method was subsequently applied to nearly two years of continuous measurements made at three near-road sites with varying site and fleet characteristics, as well as different meteorological conditions. Emission factors proved to be a useful metric in normalizing the site differences, and provided insight on inter- and intra- fleet emissions characteristics.

Download or read book Effect of Load Simulation on Auto Emissions and Model Performance written by Peter A. Gabele and published by . This book was released on 1983 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study was undertaken to examine the accuracy of an automobile emission rate model and the water brake dynamometer procedure used in the model's development. Using wheel torque-meters, actual road loads were recorded and later simulated with the vehicle on an electric dynamometer. Emissions results from tests using this load simulation were compared with results from tests using water brake simulation. Emission results were also compared to values predicted using the EPA's Automobile Exhaust Emission Modal Analysis Model.

Download or read book Emissions from Vehicles Tailpipe and Vehicle Re entrained Road Dust written by Dongzi Zhu and published by . This book was released on 2010 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emissions from transportation are some of the largest sources of urban air pollution. Transportation emissions originate from both the engine-through combustion processes and non-tailpipe re-suspended road dust emissions induced by vehicle travel on unpaved and paved roads. Gaseous and particulate emissions from transportation sources have negative impacts on human health, visibility and may influence the global radiation balance. Fugitive dust emissions originating from vehicle travel on paved and unpaved roads constitute a significant fraction of the PM10 in many areas of the western US impacting their attainment status of National Ambient Air Quality Standards. The research used three novel instrument platforms developed at the Desert Research Institute. The In-Plume Emissions Test Stand (IPETS) was designed to provide characterization of exhaust emissions from in-use individual vehicles or engines by analyzing air as close as 1 m from the exhaust port. Real-world emission factors can be quantified by in-plume measurements and provide more realistic measures for emission inventories, source modeling, and receptor modeling than certification measurements. The Testing Re-entrained Aerosol Kinetic Emissions from Roads (TRAKER) provides an effective alternate approach to the EPA AP-42 road dust emissions estimation techniques by sampling 1000s of km of roads versus isolated 3 m sections. The Portable Deposition Monitoring Platform (PDMP incorporates PM and meteorological instruments to characterize the downwind change in particle concentrations to define depositional losses in different environments. The research outcome provides important knowledge for understanding diesel engine emissions, road dust emissions and aerosol deposition process near road sources.

Download or read book Microscale Emissions Modeling System written by Jeffrey Brian Gerfen and published by . This book was released on 2002 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Review of Emission Factors and Models for Road Vehicle Non exhaust Particulate Matter written by P. G. Boulter and published by . This book was released on 2005 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: