Author: Yan Wang
Publisher:
ISBN:
Category :
Languages : en
Pages : 209
Book Description
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.
Modeling the Evolution of Vehicle Exhaust Plume Near Road and in Laboratory Dilution Systems Using the CTAG Model
Author: Yan Wang
Publisher:
ISBN:
Category :
Languages : en
Pages : 209
Book Description
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.
Publisher:
ISBN:
Category :
Languages : en
Pages : 209
Book Description
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.
Modelling of Vehicle Exhaust Plumes Using Lattice Gas Methods
Author: R. D. Kingdon
Publisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 19
Book Description
Publisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 19
Book Description
Modelling of Vehicle Exhaust Plume Using Lattice Gas Methods : a Feasibility Study
Author: R. D. Kingdom
Publisher:
ISBN:
Category : Plumes (Fluid dynamics)
Languages : en
Pages : 19
Book Description
Publisher:
ISBN:
Category : Plumes (Fluid dynamics)
Languages : en
Pages : 19
Book Description
Modelling Urban Vehicle Emissions
Author: M. Khare
Publisher: Computational Mechanics
ISBN:
Category : Nature
Languages : en
Pages : 240
Book Description
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.
Publisher: Computational Mechanics
ISBN:
Category : Nature
Languages : en
Pages : 240
Book Description
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.
Fundamentals of Environmental Discharge Modeling
Author: Lorin R. Davis
Publisher: CRC Press
ISBN: 1351446622
Category : Science
Languages : en
Pages : 178
Book Description
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.
Publisher: CRC Press
ISBN: 1351446622
Category : Science
Languages : en
Pages : 178
Book Description
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.
Automobile Exhaust Emission Testing
Author: H. Klingenberg
Publisher: Springer Science & Business Media
ISBN: 3642802435
Category : Science
Languages : en
Pages : 412
Book Description
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.
Publisher: Springer Science & Business Media
ISBN: 3642802435
Category : Science
Languages : en
Pages : 412
Book Description
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.
Emission Control Modeling
Author:
Publisher:
ISBN: 9780768007527
Category : Technology & Engineering
Languages : en
Pages : 103
Book Description
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.
Publisher:
ISBN: 9780768007527
Category : Technology & Engineering
Languages : en
Pages : 103
Book Description
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.
Measurements Within the Exhaust Plume of a Passenger Car Under Real-atmospheric Dilution and On-road Driving Conditions
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Exhaust Systems' Models Investigation by Theoretical Group Methods
Author: Jörg Volkmann
Publisher: Cuvillier Verlag
ISBN: 3867274223
Category :
Languages : en
Pages : 153
Book Description
Publisher: Cuvillier Verlag
ISBN: 3867274223
Category :
Languages : en
Pages : 153
Book Description
Measurements Within the Exhaust Plume of a Passenger Car Under Real-atmospheric Dilution and On-road Driving Conditions
Author: Sibylle von Löwis of Menar
Publisher:
ISBN:
Category :
Languages : en
Pages : 105
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 105
Book Description