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Korremla, Shiva K. Sainoju. "Experimental investigation of steady state heat transfer phenomenon in Pontiac G6 vehicle exhaust system." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2007. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
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Wiemeler, Dirk. "Aero acoustic on automotive exhaust systems." Thesis, Lyon, INSA, 2013. http://www.theses.fr/2013ISAL0018.
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Dans les systèmes d'échappement automobile, les sources de bruit d'origine aéro-acoustique représentent une partie importante du contenu fréquentiel, objectivement et subjectivement identifiable. De robustes procédures de tests ont été mises en place mais la simulation du contenu du bruit n'a pas encore fait ses preuves dans les processus de développement au quotidien. Cette thèse montre que le bruit aéro-acoustique provenant de sources type dipôle est dominant pour ce qui concerne les systèmes automobiles. La simulation des écoulements à l'origine de ces bruits spécifiques combinée avec les outils de calculs acoustiques classiques est très lourde voir tout simplement impossible. Le but de cette thèse est d'analyser la loi d'échelle pour des modèles de sources compactes, permettant de déterminer l'émission de la puissance acoustique selon différentes configurations géométriques "simples" et généralement répandues (par ex. tube perforé, diaphragme placé dans un tube…) basées sur des données empiriques. Il est démontré à l'aide de simulations que son utilisation est simple et que la précision de ces modèles de sources est satisfaisante si l'on ne s'écarte pas trop des géométries déjà analyséesOn automotive exhaust systems aero acoustic noise is a dominant and critical noise content, which is clearly objectively and subjectively detectable. Robust test procedures are established but the simulation of this noise content has not gained ground in the real life development processes. This thesis shows that the dominating characteristic of the aero acoustic noise of automotive systems is dipole noise. The simulation of these specific noise sources with classical computational areo acoustics is very cumbersome or even just impossible. The aim of the thesis is a review of the scaling law approach for compact source models, enabling the determination of the sound power emission of discret configurations based on empirical data. Application simulations show that the use of these source models is simple and that the accuracy is acceptable within the geometry limits analysed
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Bell, Arthur. "The effect of fuel formulation on the exhaust emissions of spark ignition engines." Thesis, Link to the online version, 2006. http://hdl.handle.net/10019.1/1335.
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Glenn, Bradley C. "Coordinated control of the turbo electrically assisted variable geometry turbocharged diesel engine with exhaust gas recirculation." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1127225590.
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Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xv, 178 p.; also includes graphics (some col.). Includes bibliographical references (p. 153-158). Available online via OhioLINK's ETD Center
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Bateebe, Irene. "Investigation of Probable Pollution from Automobile Exhaust Gases in Kampala City, Uganda : To Assess the current automobile exhaust gas emission levels and characterize the emissions from different automobile types." Thesis, KTH, Energiteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-92013.
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It is estimated that transport sources in developing countries contribute about 4% of the global fossil carbon dioxide versus 18% by industrialized countries. The cost of urban air pollution is estimated to be 2% of GDP in developed countries and more than 5% in developing countries. With an annual vehicle registration growth of over 30% in 2008 and a population growth rate of 6%, the number of automobiles in Kampala city of Uganda is expected to continue growing exponentially. Most of the vehicles used are imported into the country when quite old with worn out engines and low energy efficiencies. As a result, such vehicles profusely emit exhaust gases which may be harmful to both human health and the environment. Controlling pollution from the transport sector is vital to improving the quality of air and protecting public health. The objective of this dissertation was to determine the level of pollution from automobile exhaust gases in Kampala City and its impacts on human health and the environment. The study involved the analysis of tail pipe emissions using a gas analyser. It covered mini buses, motorcycles and personal vehicles which constitute 92% of the Kampala vehicle parc. It was established that the main types of exhaust gases from the automobiles were CO2, NOx, CO, NO and HC. The findings estimated the highest level of NOx tail pipe emissions at 0.15 mg/m3, HC emissions at 2.59 mg/m3, CO at 110 mg/m3 and 286.6 mg/m3 for CO2. The reported ambient air emissions were estimated at 0.18 ppm, 14000 ppm and 1.3 ppm corresponding to NO2, CO2 and CO, respectively. The study further investigated the impact of four mitigation methods on emission levels using the LEAP model. The impact of increasing penetration of city buses, introduction of tail pipe emission standards and hybrid cars and improvement of vehicle fuel economy were investigated. It was found that if left unabated, the emissions will continue to grow with the increasing number of motor vehicles. Implementation of the proposed mitigation methods resulted in a reduction in the GWP reduced by 52%, 51%, 17% and 8.5%, respectively. It is recommended that a comprehensive motor vehicle pollution control program be designed to implement the proposed NEMA vehicle emission standards. Establishment of an integrated transport system promoting the growth in number of city buses should be made a priority to reduce on emission levels and enable the decongestion of Kampala city.
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Bachman, William Hendricks. "Towards a GIS-based modal model of automobile exhaust emissions." Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/21762.
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Dohanich, Francis Albert. "On-Road Remote Sensing of Motor Vehicle Emissions: Associations between Exhaust Pollutant Levels and Vehicle Parameters for Arizona, California, Colorado, Illinois, Texas, and Utah." Thesis, University of North Texas, 2003. https://digital.library.unt.edu/ark:/67531/metadc5524/.
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On-road remote sensing has the ability to operate in real-time, and under real world conditions, making it an ideal candidate for detecting gross polluters on major freeways and thoroughfares. In this study, remote sensing was employed to detect carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxide (NO). On-road remote sensing data taken from measurements performed in six states, (Arizona, California, Colorado, Illinois, Texas, and Utah) were cleaned and analyzed. Data mining and exploration were first undertaken in order to search for relationships among variables such as make, year, engine type, vehicle weight, and location. Descriptive statistics were obtained for the three pollutants of interest. The data were found to have non-normal distributions. Applied transformations were ineffective, and nonparametric tests were applied. Due to the extremely large sample size of the dataset (508,617 records), nonparametric tests resulted in "p" values that demonstrated "significance." The general linear model was selected due to its ability to handle data with non-normal distributions. The general linear model was run on each pollutant with output producing descriptive statistics, profile plots, between-subjects effects, and estimated marginal means. Due to insufficient data within certain cells, results were not obtained for gross vehicle weight and engine type. The "year" variable was not directly analyzed in the GLM because "year" was employed in a weighted least squares transformation. "Year" was found to be a source of heteroscedasticity; and therefore, the basis of a least-squares transformation. Grouped-years were analyzed using medians, and the results were displayed graphically. Based on the GLM results and descriptives, Japanese vehicles typically had the lowest CO, HC, and NO emissions, while American vehicles ranked high for the three. Illinois, ranked lowest for CO, while Texas ranked highest. Illinois and Colorado were lowest for HC emissions, while Utah and California were highest. For NO, Colorado ranked highest with Texas and Arizona, lowest.
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Grillo, Federico. "Structure and reactivity of model oxides related to automobile exhaust catalysis." Thesis, Cardiff University, 2007. http://orca.cf.ac.uk/56181/.
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In this thesis, different ceria and barium oxide based model systems, related to automobile exhaust catalysis, are studied, with the aim of characterizing their structure and reactivity. Chapter 1 is an introduction to the relevance of surface science studies and its cross links with heterogeneous catalysis. The knowledge of a process at atomic scale, which can ultimately be achieved through surface science, can help to improve the design and performance of a material. A description of the techniques used is presented in Chapter 2. The studies of ceria based systems are described in Chapter 3. An introduction to the ceria and oxygen storage capacity (OSC) in ceria containing materials is given. Oxygen adsorption investigations on a CeO2(111) single crystal are presented in the second part. Finally, the preparation and characterisation of CeO2-X layers on a Cu(111) single crystal and, how preparation conditions dictate the ceria overlayer structure and oxidation state, is presented. Chapter 4 concerns the study of oxidised barium layers related to NSR (NOx Storage and Reduction). This involves the preparation of BaOx layers on a Pt(111) single crystal and BaO(100) layers on a Cu(111) single crystal. These layers were exposed to both in situ mixed NO and O2 gases and premixed NO and O2 gases. In the case of BaO(100)/Cu(111), during the latter experiments, nitrite groups could be observed to form on the surface. The preparation of NSR model systems Pt/BaO*/a-Al2O 3(0001) and BaO*/Pt/ct-Al2O3(0001) using traditional, wet chemistry, methods is described in Chapter 5. The model systems were characterised using XPS and air AFM. Finally, the same techniques were used to evaluate NOx storage capabilities of those model systems. Chapter 6 summarises the conclusions.
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Jones, Isabel Zoe. "A surface science study of automobile exhaust gas reactions on palladium." Thesis, University of Reading, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298639.
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Rongchai, Kanchit. "The High Temperature Condensation Particle Counter (HT-CPC) : a new instrument for a measurement of solid particulate matter." Thesis, University of Cambridge, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708259.
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Sayle, Thi Xuan Tran. "Computer simulation studies of the metal-oxide support in automobile exhaust catalysis." Thesis, University of Bath, 1993. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336167.
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Lui, Wing-man, and 呂穎雯. "A study on the effectiveness of air pollution control policy on motor vehicles in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B45013147.
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Valleron, Arthur. "Etude et optimisation de capteurs de gaz a base de dioxyde d’etain en conditions d’une ligne d’echappement automobile." Thesis, Saint-Etienne, EMSE, 2011. http://www.theses.fr/2011EMSE0613/document.
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Cette étude est dédiée à l’optimisation de capteurs chimiques de gaz de type résistifs à base de dioxyde d’étain (SnO2) pour l’application en ligne d’échappement automobile. Les capteurs sont élaborés par la technique de sérigraphie qui permet la production en masse de capteurs robustes sur substrat alumine. En vue de l’application automobile visée, les capteurs ont été optimisés par l’ajout d’une couche protectrice poreuse déposée sur l’élément sensible de SnO2. Le comportement de ces capteurs a été étudié en fonction de différents paramètres, comme la température et la vitesse des gaz, représentatifs de conditions d’échappement automobile. De plus, une modélisation « simple » de la réponse électrique des capteurs en fonction de la concentration d’un ou plusieurs gaz polluants cibles a été proposéeThis study is dedicated to the optimization of chemical gas sensors based on resistive type tin dioxide (SnO2) for automotive exhaust application. The sensors were produced by screen-printing technique which allows mass production of robust sensors on alumina substrate. In regards of the automotive application, the sensors were optimized by adding a porous protective layer deposited on the sensing element SnO2. The behaviour of this type of gas sensors was studied depending on gas parameters such as gas temperature and velocity, representative of real operation conditions. In addition, a “simple” modelisation of the electrical response of sensors depending on the concentration of one or more gaseous targets is proposed
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Van, Vuuren Christiaan Michael. "Modelling of internal combustion engine intake and exhaust processes." Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52343.
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Thesis (MScEng)--University of Stellenbosch, 2001.ENGLISH ABSTRACT: This thesis is concerned with unsteady, one-dimensional flow, which closely mimics those found in the manifolds of internal combustion engines. The physical equations describing problems of this nature are presented and some of the important concepts introduced. These equations and concepts were verified by comparison to published results. The Method of Characteristics (MaC) for unsteady one-dimensional flow with friction and heat transfer was used to analyse the gas flow through the inlet and exhaust systems of an engine. The theoretical derivation of unsteady gas dynamic boundary conditions is presented and the integration with the unsteady pipe flow explained. A simulation flow model was developed to analyse the flow by using the Mae. Thisflow model was then incorporated into an engine simulation program, ESA,to simulate internal combustion engines and to predict the performance of a specific engine. A cam-profile model and an in-cylinder thermodynamic model are used to complete the ESAsoftware. Experimental work was done on a modified Nissan Z24/NA20 engine to evaluate the simulation model. The manifolds of the Nissan Z24/NA20 were modified to isolate one of the cylinders for a proper single cylinder model. More experimental work was done on a Volkswagen 1.6£ 8-valve and a 1.6£ 20-valve engine to obtain performance data on two inlet manifolds developed using the ESAsoftware. Performance data and pressure traces in the inlet manifold of the Nissan Z24/NA20 were recorded for comparison with the ESA software. Good correspondence was found between tested and modelled data and the differences varied between ±5% on engine performance data and pressure wave frequency predictions, and ± 10% on pressure pulse amplitudes.
AFRIKAANSE OPSOMMING: Hierdie tesis handeloor bestendige, eendimensionele vloei, wat die gasvloei in spruitstukke van binnebrandenjins naboots. Die nodige vergelykings wat hierdie tipe probleme beskryf asook van die belangrikste konsepte, word bespreek. Hierdie vergelykings en konsepte is met behulp van gepubliseerde data geverifieer. Die Metode van Karakteristieke (MVK) vir bestendige, eendimensionle vloei met wrywing en warmte oordrag, is gebruik om die gasvloei deur inlaat en uitlaat sisteme van 'n enjin te analiseer. Die teoretiese afleiding van bestendige gasdinamiese randvoorwaardes asook hul integrasie met die bestendige pypvloei, word verduidelik. 'n Simulasie vloeimodel is ontwikkelom die vloei met behulp van die metode van karakteristieke te analiseer. Hierdie vloeimodel is deel van 'n omvattende enjinsimulasie program, ESA. Dit word gebruik om binnebrandenjins te simuleer en enjinwerkverrigting te voorspel. 'n Nokprofielmodel en 'n termodinamiese ontbrandingsmodel word gebruik om die enjinsimulasie program af te rond. Eksperimentele toetse op 'n gemodifiseerde Nissan Z24/NA20 enjin is gebruik om die simulasie model te evalueer. Die spruitstukke van die Nissan Z24/NA20 is aangepas om een van die silinders te isoleer om so 'n geskikte enkelsilindermodel te skep. Verdere eksperimentele toetse is gedoen op Volkswagen 1.6£8- klep en 1.6£ 20-klep enjins. Werkverrigtingsdata is verkry op twee nuwe inlaatspruitstukke wat met behulp van die ESAsagteware ontwerp is. Werkverrigtingsdata en drukverdelingsdata in die inlaatspruitstuk van die Nissan Z24/NA20is aangeteken om te vergelyk met die resultate van die ESAsagteware. Goeie ooreenstemming is verkry tussen toets- en gemoduleerde data. Die verskille varieer tussen ±5% op enjin werkverrigtingsdata en drukpulsfrekwensie voorspellings, en ± 10%op drukpuls-amplitudes.
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Clarkson, Rory John. "A theoretical and experimental study of automotive catalytic converters." Thesis, Coventry University, 1995. http://curve.coventry.ac.uk/open/items/cb5d72be-4f37-c710-5e08-df9c44201b6f/1.
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In response to the increasingly widespread use of catalytic converters for meeting automotive exhaust emission regulations considerable attention is currently being directed towards improving their performance. Experimental analysis is costly and time consuming. A desirable alternative is computational modelling. This thesis describes the development of a fully integrated computational model for simulating monolith type automotive catalytic converters. Two commercial CFD codes, PHOENICS and STAR-CD, were utilised to implement established techniques for modelling the flow field in catalyst assemblies. To appraise the accuracy of the flow field predictions an isothermal steady flow rig was designed and developed. A selection of axisymmetric inlet diffusers and 180o expansions were tested, with the velocity profile across the monolith, the wall static pressure distribution along the inlet section and the total pressure drop across the assembly being measured. These datum sets were compared with predictions using a variety of turbulence models and solution algorithms. The closest agreement was achieved with a two-layer near wall approach, coupled to the fully turbulent version of the RNG k-ε model, and a nominally second order differencing scheme. Even with these approaches the predicted velocity profiles were too flat, the maximum velocity being as much as 17.5% too low. Agreement on pressure drops was better, the error being consistently less than 10%. These results illustrate that present modelling techniques are insufficiently reliable for accurate predictions. It is suggested that the major reason for the relatively poor performance of these techniques is the neglecting of channel entrance effects in the monolith pressure drop term. Despite these weaknesses it was possible to show that the model reproduces the correct trends, and magnitude of change, in pressure drop and velocity distributions as the catalyst geometry changes. The PHONETICS flow field model was extended to include the heat transfer, mass transfer and chemical reactions associated with catalysts. The methodology is based on an equivalent continuum approach. The result is a reacting model capable of simulating the three-dimensional distribution of solid and gas temperatures, species concentrations and flow field variables throughout the monolith mat and the effects that moisture has on the transient warm-up of the monolith. To assess the reacting model’s accuracy use was made of published light-off data from a catalyst connected to a test bed engine. Comparison with predicted results showed that the model was capable of reproducing the correct type, and time scales, of temperature and conversion efficiency behaviour during the warm-up cycle. From these predictions it was possible to show that the flow distribution across the monolith can significantly change during light-off. Following the identification, and subsequent modelling, of the condensation and evaporation of water during the warm-up process it was possible to show that, under the catalyst conditions tested, these moisture effects do not affect light-off times. Conditions under which moisture might affect light-off have been suggested. Although the general level of model accuracy may be acceptable for studying many catalyst phenomena, known deficiencies in the reaction kinetics used, errors in the flow field predictions, uncertainty over many of the physical constants and necessary model simplifications mean that accurate quantitative predictions are still lacking. Improving the level of accuracy will require a systematic experimental approach followed by model refinements.
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Sturgess, M. "Selective catalytic reduction for light-duty diesel engines using ammonia gas." Thesis, Coventry University, 2012. http://curve.coventry.ac.uk/open/items/aa3c644b-15fd-429a-b457-a831d44c5dce/1.
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This thesis describes an investigation into the spatial species conversion profiles of a Cu-zeolite SCR under engine conditions at low exhaust gas temperatures; this was then compared with a CFD model that models the catalyst via a porous medium measuring 5 x 5 x 91 cells assuming a uniform cross-sectional flow distribution. Species conversion rates were sampled at fixed points in the axial direction. The analysis of the spatial conversion profiles is a more rigorous method in assessing the ability of a mathematical model to predict the experimental data. It can also assist in the optimisation of the catalyst size, minimising packaging requirements and manufacturing costs. The experiments were undertaken on a light-duty diesel engine at a speed of 1500rpm, and at a load of 6bar BMEP; this provided exhaust gas temeraqtures between 200 and 220°C. NO2:NOx ratios were controlled by changing the size and position of the diesel oxidation catalyst, the inlet NH3: NOx ratio was also also varied, ammonia gas was used instead of urea for the purposes of simlicity. The advantage of testing on an actual engine over lab-babed studies is that the conditions such as exhaust gas composition are more realistic. A 1D CFD model was constructed using the ‘porous medium approach’ with kinetics obtained from open literature. Results from the simulations were then compared with the experimental data for the same engine conditions. It was observed that the majority of the NOx conversion took place in the first half of the brick for all NH3: NOx ratios investigated, and that the formation of N2O via NO2 and ammonia had the same influence as the ‘fast’ SCR reaction just after the inlet, which the CFD model failed to predict for the base case analyses. The influence of the inlet ammonia on the model was also noticed to be greater than in the experiments. Simple transient analyses were also undertaken on the short SCR bricks for NO2: NOx ratios of 0.6 and 0.07, and it was observed that the response time to steady-state was noticeably higher in the experiments than in the model. Modifications made to the model, including decreasing the influence of the ‘fast’ SCR reaction, and the addition of an empirical term onto the ammonia adsorption provided a noticeably better agreement for different NH3: NOx injection ratios. The desorption kinetics in the model were also altered by increasing the strength of the bonding of the ammonia onto the adsorption sites. This improved the transient agreement between the model and the experiments, but reduced the steady-state concentrations at the exit of the brick for all NH3:NOx ratios investigated.
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Kelly, Kenneth John. "The effects of fuels and test cycles on light-duty vehicle exhaust emissions." Ohio : Ohio University, 1998. http://www.ohiolink.edu/etd/view.cgi?ohiou1176490219.
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Sarshar, Zahra. "Hydrocarbon trap adsorbents for reducing cold-start emissions of automotive exhaust." Thesis, Université Laval, 2008. http://www.theses.ulaval.ca/2008/25807/25807.pdf.
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Toral, del Rio Maria Isabel. "An analysis of the influence of phosphorus poisoning on the exhaust emission after treatement systems of light-duty diesel vehicles." Thesis, Nelson Mandela Metropolitan University, 2007. http://hdl.handle.net/10948/697.
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Climate change has become a discussion topic of exponentially increasing urgency and importance amoung world leaders of all disciplines. These changes are brought about by the emission of so-called Greenhouse gases from various human activities. The primary cause of CO2 emissions is the burning of the Earth’s supply of nonrenewable natural fossil fuels like coal, oil and natural gas. The world first agreed on the prevention of “dangerous” climatic changes at the Earth Summit in 1992. The Kyoto Protocol of 1997 was the first step toward protection of the atmosphere and prescribes restrictions on emission pollutants. Since then the vehicle gas emissions are being controlled by means of different gas emissions norms, like the European Union Norm in Europe. The automotive manufacturers and suppliers are collectively working on reducing overall vehicle emissions. They are focusing on several different emission limiting possibilities, for example improved engine design, special fuel development and exhaust gas treatment systems. The exhaust gas treatment process requires continuous controlling and management of the exhaust gas emissions while driving a vehicle. Certain factors such as high emission temperatures have a negative influence on the life span of these systems. Their functionality and durability is also known to be reduced by the presence of chemical poisoning species like sulphur, phosphorus, zinc and calcium. The chemical poisoning species are produced during combustion of fuel and engine oil. They are therefore contained in the exhaust emissions and can poison the catalyst when passing over it. Phosphorous poisoning is particularly problematic and should be reduced considerably. This study involves the investigation of the phosphorous poisoning process and aims to provide clarity regarding the influences of different fuel and oil compositions on the severity of the process. Engine oil and biodiesel are two major sources of phosphorous poisoning. The phosphorus contained in biodiesel fuel is a natural component and can be minimized during the refining procedure. In contrast to others studies, the biodiesel fuel used during this project was SME (Soya Methyl Ester) with a 20% biodiesel content. This choice of fuel was made because of the increasingly important role that this type of biodiesel is playing in the European market and the future tendency to increase the percentage of biodiesel in the mixture with standard diesel fuel. The phosphorus contained in engine oil is a necessary additive to retain the antioxidant and anti-wear properties of the oil. This study examined the poisoning influences from the most commonly used phosphorus containing oil additive, Zinc Dithiophosphates (ZDDP), as well as a Zn-free, phosphorus containing anti-wear oil additive. This formulation provides information about the phosphorus poisoning process as caused by the engine oil in the absence of Zn in the oil additives. The results show how the phosphorus content in biodiesel fuel affects the functionality of the exhaust gas treatment systems and the importance of reducing the permitted content of phosphorus contained in the fuel. Reducing the phosphorus content in the fuel will conserve the functionality of the exhaust gas treatment systems during their operational life and thereby protect the environmental from emission pollutants. It also provides insight into the differences in the poisoning processes when the phosphorus deposited on the catalyst comes from biodiesel fuel and when it comes from the engine oil. Finally the results also illustrate the influence of different phosphorous forms contained in engine oil additives on the catalyst poisoning process. This information could be used for the development of new oil additive formulations.
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Louw, Andre. "Investigating the benefits of using selected lean techniques at a South African exhaust manufacturer-a case study." Thesis, Nelson Mandela Metropolitan University, 2010. http://hdl.handle.net/10948/1518.
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This study investigates the implementation of supermarket-based scheduling of parts at a South African exhaust manufacturing plant. The study firstly investigates the requirements the manufacturer had to contend with in ensuring a valuable contract was won. The nature of the contract is such that it warrants building of a new facility. The design of the facility and the manufacturing processes is of importance as some Lean techniques are employed during these early stages. The research takes the form of a case study and data is collected mainly through interviews with staff, but also from direct observations on the shop-floor. Interviews were conducted with: - key project leaders responsible for the original design and commissioning of the facility; - production managers and technical staff currently operating the plant; and - shop-floor personnel involved in daily production and logistics operations within the plant. The as-built facility and procedures are compared with literature found on the topic of Lean manufacturing. Various findings are recorded, both on conforming to and not conforming to typical Lean theory. Potential changes are suggested in the following areas: - a Pull strategy is proposed to coincide with the appointment of a so-called pacemaker station; - a pacemaker would need to be further supported by a production leveling strategy; - although quality delivered to the customer is reported as very high, potential improvements are still possible by introducing an "at source" approach to reduce rework; and - finally, a Total Productive Maintenance (TPM) program will serve to reduce downtime even further.
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Athavale, Jayati Deepak. "Evaluation of Internal Fin Geometry for Heat Transfer Enhancement in Automobile Exhaust Energy Harvesting Systems." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/54017.
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Thermoelectric generators (TEGs) are currently being explored for their potential in harvesting energy from automobile exhaust. TEGs in form of an appropriate TEG- Heat exchanger module can utilize the temperature difference between the hot exhaust gases and the automobile coolant and convert it into electrical voltage. The amount of power is anticipated to be a few hundred watts depending on the temperature gradient and the material of the TEGs.
The focus of this study is increasing the hot side heat transfer for improved performance of the thermoelectric generators using two different internal fins — louvered fins and herringbone wavy fins. The multi-louvered fins basically have 'multi flat plate' behavior and will enhance the heat transfer by deflecting the air from its original path and aligning it with the plane of the louvers. Herringbone fins are used to lengthen the path of airflow allowing for greater residence time and better mixing of the flow. They also provide for greater wetted surface area achieving higher heat transfer. The flow and heat transfer behavior inside the exhaust pipe test section with internal fins is modeled using commercial numerical software.
The thermal and flow behavior through both these internal fins depends to a large extent on geometric parameters and fin arrangement. Optimization of the fin design is considered to determine the configuration that provides highest heat transfer while providing least pressure drop across the pipe length. The heat transfer and pressure drop characteristics are compared to the baseline flow without any fin enhancement.Master of Science
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Thompson, Megan Elizabeth Dove. "Fabrication and Testing of a Heat Exchanger Module for Thermoelectric Power Generation in an Automobile Exhaust System." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/19233.
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Thermoelectric generators (TEGs) are currently a topic of interest in the field of energy harvesting for automobiles. In applying TEGs to the outside of the exhaust tailpipe of a vehicle, the difference in temperature between the hot exhaust gases and the automobile coolant can be used to generate a small amount of electrical power to be used in the vehicle. The amount of power is anticipated to be a few hundred watts based on the temperatures expected and the properties of the materials for the TEG. This study focuses on developing efficient heat exchanger modules for the cold side of the TEG through the analysis of experimental data. The experimental set up mimics conditions that were previously used in a computational fluid dynamics (CFD) model. This model tested several different geometries of cold side sections for the heat exchanger at standard coolant and exhaust temperatures for a typical car. The test section uses the same temperatures as the CFD model, but the geometry is a 1/5th scaled down model compared to an full-size engine and was fabricated using a metal-based rapid prototyping process. The temperatures from the CFD model are validated through thermocouple measurements, which provide the distribution of the temperatures across the TEG. All of these measurements are compared to the CFD model for trends and temperatures to ensure that the model is accurate. Two cold side geometries, a baseline geometry and an impingement geometry, are compared to determine which will produce the greater temperature gradient across the TEG.
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Lakkis, Sari. "New Gas Sensor for Exhaust Emissions of Internal Combustion Engines." Thesis, Versailles-St Quentin en Yvelines, 2014. http://www.theses.fr/2014VERS0064/document.
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L’analyse des gaz d’échappement des moteurs à combustion interne a été traditionnellement réalisée en laboratoires en utilisant des analyseurs de gaz en vrac avec des équipements coûteux. Afin de créer un système capable de réaliser le travail de ces analyseurs, un capteur pouvant détecter plusieurs gaz simultanément est indispensable pour en mesurer la concentration. En effet, utiliser un capteur pour chaque gaz est couteux et peut amener à des procédures complexes d’analyse en raison des différentes technologies utilisées. De plus, l’utilisation de multiples capteurs donne lieu à une perte de ressources financières et humaines. Pour pallier ce problème, une approche alternative proposée dans cette thèse consiste à utiliser un seul capteur pour l’analyse simultanée des différents gaz. Cette approche contribue à réduire la complexité des analyses, la taille et la collecte de données des mesures de gaz mentionnés précédemment. Elle permet également la baisse du coût de l’ensemble du système des mesures.Cette thèse présente la conception, la méthodologie et le développement d’une nouvelle approche pour la mesure de la concentration de gaz utilisant le traitement d’images numériques à travers la modélisation du mélange des couleurs d’émission de lumière dans le tube de décharge de gaz. L’application du modèle inverse permet d’obtenir le pourcentage de chaque gaz dans un mélange contenant jusqu'à quatre gaz connaissant la couleur d’émission du mélange et la couleur d’émission de chaque gaz. Nous discutons aussi le potentiel de certaines méthodes quant à leurs propriétés de miniaturisation et leurs limites. Une comparaison entre les différents capteurs miniaturisés est réalisée en termes suivant la sensibilité, la sélectivité, le coût et d’autres conditions. Pour atteindre les objectifs de recherche, les problèmes techniques rencontrés tels que la modélisation de mélange des couleurs, l’étalonnage de capteurs pour l’acquisition d’images, et le traitement des erreurs de mesures ont été identifiés et des solutions ont été proposéesGases represent one of the most important key measurands in many industrial and domestic activities. The need to detect single gas or a group of gases at the same time varies from one application to another. One of the most important applications of gas sensing is in the concentration measurement of exhaust emissions in internal combustion engines. The variety of gases emitted by these engines and the necessity for a precise measurement of their concentrations are the major incentives for researchers to develop gas sensors that are not only limited to a certain type of gases but to a variety of gases. The most interest gases include CO, NO, NO2, NH4, SO2, CO2, CH4 and other hydrocarbons. These gases can be harmful to human health if present beyond a certain concentration. The analysis of exhaust emissions of internal combustion engines has traditionally been achieved in laboratories using bulk gas analyzers and costly equipments. In order to create a system which can do the work of these analyzers, a sensor that can measure the concentration of multiple gases at the same time is needed. Instead of using a sensor for each gas which is costly and introduce another complexity to the analysis procedure due to the different technologies that are used in the detection of different types of gases. This directly translates into loss of financial and human resources that could otherwise be productively used. In an effort to remedy this situation, this dissertation proposes an alternate approach that uses one sensor to analyze multiple gases simultaneously. This has a significant potential in reducing the aforementioned complexity, size and data collection tasks, and at the same time can lower the cost of the overall system.This dissertation presents the design, methodology, and development of a new method for gas concentration measurement using digital image processing through modeling the color mixing of light emissions in gas discharge tube. The application of the inverse model allows us to get the percentages of each gas in a mixture of up to four gases knowing already the color of emission of the whole mixture and the color of emission of each gas alone. It also discusses the miniaturization potential of some of the methods that are promising in the ability of their miniaturization but suffer from different problems. A comparison is also done among the miniaturized sensors in terms of different parameters like sensitivity, selectivity, cost and other terms. In achieving the research objectives, major technical challenges such as color mixing modeling, imaging sensor calibration, and measurements’ error handling have been successfully identified and addressed
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Johnson, Kent Charles. "Quantitative assessment on in-use emissions from on-road diesel vehicles." Diss., UC access only, 2009. http://proquest.umi.com/pqdweb?index=134&did=1974971641&SrchMode=1&sid=1&Fmt=7&retrieveGroup=0&VType=PQD&VInst=PROD&RQT=309&VName=PQD&TS=1270570208&clientId=48051.
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Yeung, Kit-choi James, and 楊傑材. "A study of the air pollution situation and its effects in urban Hong Kong caused by land-based transport." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31952501.
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魏海然 and Hoi-yin Ngai. "The effect of private car policies on air quality." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31255267.
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Walsh, Patrick McKay. "Plug-in Hybrid Electric Vehicle Supervisory Control Strategy Considerations for Engine Exhaust Emissions and Fuel Use." Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/32534.
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Defining key parameters for a charge sustaining supervisory (torque split) control strategy as well as an engine and catalyst warm-up strategy for a Split Parallel Architecture Extended-Range Electric Vehicle (SPA E-REV) is accomplished through empirically and experimentally measuring vehicle tailpipe emissions and energy consumption for two distinct control strategies. The results of the experimental testing and analysis define how the vehicle reduces fuel consumption, petroleum energy use and greenhouse gas emissions while maintaining low tailpipe emissions. For a SPA E-REV operating in charge sustaining mode with the engine providing net propulsive energy, simply operating the engine in regions of highest efficiency does not equate to the most efficient operation of the vehicle as a system and can have adverse effects on tailpipe emissions. Engine and catalyst warm-up during the transition from all-electric charge depleting to engine-dominant charge sustaining modes is experimentally analyzed to evaluate tailpipe emissions. The results presented are meant to define key parameters for a high-level torque-split strategy and to provide an understanding of the tradeoffs between low energy consumption and low tailpipe emissions.
The literature review gives a background of hybrid and plug-in hybrid vehicle control publications including tailpipe emissions studies, but does not include experimental results and comparisons of supervisory strategies designed for low fuel consumption and low tailpipe emissions the SPA E-REV architecture. This paper details the high-level control strategy chosen for balancing low energy consumption and low tailpipe emissions while the engine is operating. Vehicle testing data from a chassis dynamometer is presented in support of the research.Master of Science
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DI, CUNTO JULIO C. "Estudo da resistencia a corrosao de acos inoxidaveis para uso na parte fria dos sistemas de exaustao de veiculos." reponame:Repositório Institucional do IPEN, 2005. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11366.
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Made available in DSpace on 2014-10-09T12:51:09Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T14:01:23Z (GMT). No. of bitstreams: 1 11249.pdf: 6810896 bytes, checksum: d6d7eb3261a4e010e1840b22fdcc9f8a (MD5)
Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Yamin, A. K. M. "Pulsating flow studies in a planar wide-angled diffuser upstream of automotive catalyst monoliths." Thesis, Coventry University, 2012. http://curve.coventry.ac.uk/open/items/e82aae35-8737-48e2-b73d-4758a88f5e1a/1.
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Automotive catalytic converters are used extensively in the automotive industry to reduce toxic pollutants from vehicle exhausts. The flow across automotive exhaust catalysts is distributed by a sudden expansion and has a significant effect on their conversion efficiency. The exhaust gas is pulsating and flow distribution is a function of engine operating condition, namely speed (frequency), load (flow rate) and pressure loss across the monolith. The aims of this study are to provide insight into the development of the pulsating flow field within the diffuser under isothermal conditions and to assess the steady-state computational fluid dynamics (CFD) predictions of flow maldistribution at high Reynolds numbers. Flow measurements were made across an automotive catalyst monolith situated downstream of a planar wide-angled diffuser in the presence of pulsating flow. Cycle-resolved Particle Image Velocimetry (PIV) measurements were made in the diffuser and hot wire anemometry (HWA) downstream of the monoliths. The ratio of pulse period to residence time within the diffuser (J factor) characterises the flow distribution. During acceleration the flow remained attached to the diffuser walls for some distance before separating near the diffuser inlet later in the cycle. Two cases with J ~ 3.5 resulted in very similar flow fields with the flow able to reattach downstream of the separation bubbles. With J = 6.8 separation occurred earlier with the flow field resembling, at the time of deceleration, the steady flow field. Increasing J from 3.5 to 6.8 resulted in greater flow maldistribution within the monoliths; steady flow producing the highest maldistribution in all cases for the same Re. The oblique entry pressure loss of monoliths were measured using a one-dimensional steady flow rig over a range of approach Reynolds number (200 < Rea < 4090) and angles of incidence (0o < α < 70o). Losses increased with α and Re at low mass flow rates but were independent of Re at high flow rates being 20% higher than the transverse dynamic pressure. The flow distribution across axisymmetric ceramic 400 cpsi and perforated 600 cpsi monoliths were modelled using CFD and the porous medium approach. This requires knowledge of the axial and transverse monolith resistances; the latter being only applicable to the radially open structure. The axial resistances were measured by presenting uniform flow to the front face of the monolith. The transverse resistances were deduced by best matching CFD predictions to measurements of the radial flow profiles obtained downstream of the monolith when presented with non-uniform flow at its front face. CFD predictions of the flow maldistibution were performed by adding the oblique entry pressure loss to the axial resistance to simulate the monolith losses. The critical angle approach was used to improve the predictions, i.e. the oblique entry loss was limited such that the losses were assumed constant above a fixed critical angle, αc. The result showed that the perforated 600 cpsi monolith requires the entrance effect to be restricted above αc = 81o, while the losses were assumed constant above αc = 85o for the ceramic 400 cpsi monolith. This might be due to the separation bubble at the monolith entrance being restricted by the smaller hydraulic diameter of the perforated monolith thus limiting the oblique entry loss at the lower incidence angle.
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Hyland, Jackie. "The health and socioeconomic impact of traffic-related air pollution in Scotland." Thesis, University of St Andrews, 2017. http://hdl.handle.net/10023/11734.
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Traffic-related air pollution harms health, so whilst it would be advantageous to improve air quality, the socioeconomic impact of air pollution mitigation in Scotland is not fully understood. Evidence from research literature, current regulatory and policy directives and a socioeconomic analysis are required to assess the true health impact. This thesis presents the first health and socioeconomic analysis of traffic-related air pollution and health for Scotland. A critique of the literature was undertaken to determine the evidence base and the strength of evidence in terms of association and causation, between air pollution and ill health. The evidence was subsequently applied in epidemiological studies of Scottish residents, to assess the actual impact on health in Scotland. The perception of barriers and incentives for change were investigated to understand behavioural influences. Recent policy development in Scotland was reviewed, and a socioeconomic analysis of a proposed air pollution strategy in Scotland, was undertaken. The evidence from 30 cohort studies and nine literature reviews demonstrated a link between poor air quality, mortality and respiratory ill health, but the results for other health conditions were inconsistent. The links were associative rather than causal and therefore might be attributable to other factors other than air pollution. Furthermore, epidemiological studies on Scottish populations did not show health effects from traffic-related air pollution. The socioeconomic analysis suggested that an initial investment of between £27m and £44m to introduce Low Emission Zones (LEZ), and an effective active travel programme, might result in a saving of £38m in terms of Years of Life Lost (YLL) and reduction in sickness absence. It is unlikely that the Clean Air For Scotland Strategy will deliver improved air quality and health without substantial investment, better alignment of planning, and a greater public engagement to support public and active transport options.
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Bongiovanni, Alessandro. "Etude des effets promoteurs dans les réactions catalytiques de dépollution par l'argent et l'or." Doctoral thesis, Universite Libre de Bruxelles, 2007. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210682.
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La catalyse hétérogène influe sur la cinétique des réactions chimiques pour favoriser la formation de produits souhaités. Appliquée à la dépollution atmosphérique, elle permet de réduire considérablement l'émission de polluants. Son plus grand succès public est d'ailleurs sans conteste le pot catalytique pour les moteurs à essence. Malgré ce succès, beaucoup reste à faire pour améliorer la dépollution à basse température et pour des conditions d'utilisations très différentes telles que celles imposées par les moteurs Diesel et "lean burn".Lors de ce travail nous nous sommes intéressés à ces sujets. Tout d'abord, nous avons étudié l'effet du SO2 sur la réduction catalytique sélective des NOx sur des catalyseurs Ag/Al2O3 dans les conditions des moteurs Diesel. Le dioxyde de soufre est reconnu comme un poison de catalyseurs. Dans cette thèse, nous avons étudié un effet promoteur du SO2. Les catalyseurs qui ont fait l’objet de ce travail ont été préparés au laboratoire. Nous avons fait varier différents paramètres tels que la température, la nature de l'hydrocarbure ou encore la concentration de SO2 afin de mieux cerner cet effet promoteur. Nous avons mis en évidence que cet effet promoteur est observable lorsque le propène est utilisé comme réducteur, alors qu'avec le propane il s'agit plutôt d'un effet négatif du SO2.
Le deuxième sujet étudié dans ce travail est l'oxydation du CO sur des catalyseurs Au/TiO2, soit préparés au laboratoire, soit fournis comme référence du World Gold Council. Ces catalyseurs offrent l’avantage de pouvoir oxyder le CO à basse température, ce qui pourrait résoudre le problème de la pollution liée au démarrage à froid des automobiles. Ces catalyseurs subissent une désactivation que nous avons analysée par spectroscopie infrarouge (DRIFT et FTIR). Une étude XPS-SIMS de catalyseurs ayant des activités différentes nous a permis de mettre en évidence des concentrations de sodium différentes sur ces catalyseurs. Dans cette thèse, nous nous sommes plus particulièrement intéressés à l'influence du potassium. Pour mettre en évidence l'influence de celui-ci sur l'activité catalytique, des catalyseurs Au/TiO2 furent préparés en absence stricte d'alcalins et d'alcalino-terreux pour ajouter par après, de manière contrôlée, les quantités souhaitées de potassium. La composition des catalyseurs préparés fut contrôlée par XPS-SIMS. Il s'avère que la présence de potassium permet d'accroître l'activité catalytique, néanmoins il semble y avoir une concentration optimale de potassium qui varie en fonction de la composition/morphologie du catalyseur Au/TiO2 au départ, c'est-à-dire sans modification par ajout de potassium.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished
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Otto, Willem Liebrecht. "Investigating the introduction of e-mobility in South Africa." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95956.
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Supnithadnaporn, Anupit. "Three essays in program evaluation the case of Atlanta inspection and maintenance program /." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29770.
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Thesis (Ph.D)--Public Policy, Georgia Institute of Technology, 2009.Committee Chair: Noonan, Douglas; Committee Member: Castillo, Marco; Committee Member: Chang, Michael; Committee Member: Cozzens, Susan; Committee Member: Rodgers, Michael. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Kall, David. "Effect of high occupancy toll (HOT) lanes on mass vehicle emissions." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/29692.
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Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2009.Committee Chair: Guensler, Randall; Committee Member: Rodgers, Michael; Committee Member: Ross, Catherine. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Boswell, Colin R. "Atlanta automotive particulate matter exposure and evaluation." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34679.
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The following thesis titled, Atlanta Automotive Particulate Matter Exposure and Evaluation, presents data obtained as a part of a joint project with Emory University, Rollin's School of Public Health. The Atlanta Commuters Exposure (ACE) Study uses both real-time and time-integrated sampling techniques for ambient aerosol concentrations. The ACE study is unique in that it will correlate the ambient aerosol concentrations with the concurrent health measurements. The primary objective of this thesis is to measure the concentration, size distribution and the chemical composition of PM2.5 inside the vehicle cabin for several commuters. The vehicles followed a scripted route along roadways in the Atlanta metropolitan region during periods of peak traffic volume, while the compact air sampling package of both real-time and time-integrated instruments recorded data. Real-time measurements for Particulate Matter (PM) were made using compact Optical Particle Counters (OPC), a Condensation Particle Counter, and a MicroAethalometer. The time-integrated measurements for Elemental Carbon (EC), Organic Carbon (OC), Water Soluble Organic Carbon (WSOC), particulate elemental concentrations, and speciated organics required filter collection methods. Thus a compact air-sampling package was created to combine both sets of real-time and time-integrated instruments. The following results are presented for the first four commutes. The framework for analyzing and presenting results is developed, and will be used for future commutes.
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Wu, Wai-yu, and 吳惠如. "The vehicle emissions control policy in Hong Kong: a study of agenda setting." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31966366.
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Ng, Bing Benson, and 吳賓. "Cleaner alternative fuels for vehicles: a cleaner future for Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B31255036.
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Pandit, Jaideep. "Numerical and Experimental Design of High Performance Heat Exchanger System for A Thermoelectric Power Generator for Implementation in Automobile Exhaust Gas Waste Heat Recovery." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/47919.
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The effects of greenhouse gases have seen a significant rise in recent years due to the use of fossil fuels like gasoline and diesel. Conversion of the energy stored in these fossil fuels to mechanical work is an extremely inefficient process which results in a high amount of energy rejected in the form of waste heat. Thermoelectric materials are able to harness this waste heat energy and convert it to electrical power.
Thermoelectric devices work on the principle of the Seebeck effect, which states that if two junctions of dissimilar materials are at different temperatures, an electrical potential is developed across them. Even though these devices have small efficiencies, they are still an extremely effective way of converting low grade waste heat to usable electrical power. These devices have the added advantage of having no moving parts (solid state) which contributes to a long life of the device without needing much maintenance. The performance of thermoelectric generators is dependent on a non-dimensional figure of merit, ZT. Extensive research, both past and ongoing, is focused on improving the thermoelectric generator's (TEG's) performance by improving this figure of merit, ZT, by way of controlling the material properties. This research is usually incremental and the high performance materials developed can be cost prohibitive.
The focus of this study has been to improve the performance of thermoelectric generator by way of improving the heat transfer from the exhaust gases to the TEG and also the heat transfer from TEG to the coolant. Apart from the figure of merit ZT, the performance of the TEG is also a function of the temperature difference across it, By improving the heat transfer between the TEG and the working fluid, a higher temperature gradient can be achieved across it, resulting in higher heat flux and improved efficiency from the system. This area has been largely neglected as a source of improvement in past research and has immense potential to be a low cost performance enhancer in such systems. Improvements made through this avenue, also have the advantage of being applicable regardless of the material in the system. Thus these high performance heat exchangers can be coupled with high performance materials to supplement the gains made by improved figure of merits.
The heat exchanger designs developed and studied in this work have taken into account several considerations, like pressure drop, varying engine speeds, location of the system along the fuel path, system stability etc. A comprehensive treatment is presented here which includes 3D conjugate heat transfer modeling with RANS based turbulence models on such a system. Various heat transfer enhancement features are implemented in the system and studied numerically as well as experimentally. The entire system is also studied experimentally in a scaled down setup which provided data for validation of numerical studies. With the help of measured and calculated data like temperature, ZT etc, predictions are also presented about key metrics of system performance.Ph. D.
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Yoon, Seungju. "A new heavy-duty vehicle visual classification and activity estimation method for regional mobile source emissions modeling." Diss., Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-07122005-204032/.
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Thesis (Ph. D.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2006.Michael O. Rodgers, Committee Chair ; Randall L. Guensler, Committee Member ; Michael D. Meyer, Committee Member ; Michael P. Hunter, Committee Member ; Jennifer H. Ogle, Committee Member.
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Shafi, Ghufran. "Development of roadway link screening criteria for microscale carbon monoxide and particulate matter conformity analyses through application of classification tree model." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/28222.
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Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2008.Committee Chair: Guensler, Randall; Committee Member: Rodgers, Michael; Committee Member: Russell, Armistead.
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Cambridge, Shevonn Nathaniel. "The effect of compression ratio on emissions from an alcohol-fueled engine." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-09122009-040220/.
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Wright, Monica Elizabeth. "An Investigation of Urban Mobile Source Aerosol Using Optical Properties Measured by CRDT/N: Diesel Particulate Matter and the Impact of Biodiesel." PDXScholar, 2012. https://pdxscholar.library.pdx.edu/open_access_etds/673.
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Mobile source emissions are a major contributor to global and local air pollution. Governments and regulatory agencies have been increasing the stringency of regulations in the transportation sector for the last ten years to help curb transportation sector air pollution. The need for regulations has been emphasized by scientific research on the impacts from ambient pollution, especially research on the effect of particulate matter on human health. The particulate emissions from diesel vehicles, diesel particulate matter (DPM) is considered a known or probable carcinogen in various countries and increased exposure to DPM is linked to increased cardiovascular health problems in humans. The toxicity of vehicle emissions and diesel particulate emissions in particular, in conjunction with an increased awareness of potential petroleum fuel shortages, international conflict over petroleum fuel sources and climate change science, have all contributed to the increase of biodiesel use as an additive to or replacement for petroleum fuel. The goal of this research is to determine how this increased use of biodiesel in the particular emission testing setup impacts urban air quality. To determine if biodiesel use contributes to a health or climate benefit, both the size range and general composition were investigated using a comprehensive comparison of the particulate component of the emissions in real time. The emissions from various biodiesel and diesel mixtures from a common diesel passenger vehicle were measured with a cavity ring-down transmissometer (CRDT) coupled with a condensation particle counter, a SMPS, a nephelometer, NOx, CO, CO2, and O3 measurements. From these data, key emission factors for several biodiesel and diesel fuel mixtures were developed. This approach reduces sampling artifacts and allows for the determination of optical properties, particle number concentration, and size distributions, along with several important gas phase species' concentrations. Findings indicate that biodiesel additions to diesel fuel do not necessarily have an air quality benefit for particulate emissions in this emission testing scenario. The often cited linear decrease in particulate emissions with increasing biodiesel content was not observed. Mixtures with half diesel and half biodiesel tended to have the highest particulate emissions in all size ranges. Mixtures with more than 50% biodiesel had slightly lower calculated mass for light absorbing carbon, but this reduction in mass is most likely a result of a shift in the size of the emission particles to a smaller size range, not a reduction in the total number of particles. Evaluation of the extensive optical properties from this experimental set-up indicates that biodiesel additions to diesel fuel has an impact on emission particle extinction in both visible and near-IR wavelengths. The B99 mixture had the smallest emission factor for extinction at 532 nm and at 1064 nm. For the extinction at 532 nm, the trend was not linear and the emission factor peaked at the B50 mixture. Results from intensive properties indicate that emissions from B5 and B25 mixtures have Ångström exponents close to 1, typical for black carbon emissions. The mixtures with a larger fraction of biodiesel have Ångström exponent values closer to 2, indicating more absorbing organic matter and/or smaller particle size in the emissions. Additional experimental testing should be completed to determine the application of these results and emission factors to other diesel vehicles or types of diesel and biodiesel fuel mixtures.
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Grondin, Didier. "Développement d'un capteur de suies pour application automobile - Etude des paramètres clés affectant sa réponse." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEM012/document.
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Le transport routier est responsable d’une part des émissions de particules fines, notamment dans les grandes agglomérations. Celles-ci ayant des répercussions graves sur la santé humaine et l’environnement, des normes d’émissions des véhicules de plus en plus strictes sont mises en place. Des limites en nombre de particules sont imposées et une obligation de connaitre l’état de santé des organes de post-traitement des gaz d’échappement est également entrée en vigueur (On-Board Diagnostic : OBD).Les capteurs résistifs ont montré de bons résultats pour la mesure de la concentration massique des particules et ont l’avantage d’être simples à mettre en oeuvre, robustes et peu onéreux. Le principe de fonctionnement du capteur est basé sur la mesure de la conductance entre des électrodes de platine. Celle-ci augmente avec le dépôt de suies.L’objectif de ce travail de thèse est de parvenir à déterminer les paramètres clés qui affectent la réponse du capteur. Trois flux de suies présentant des distributions en taille différentes ont été sélectionnés et caractérisés. Un quatrième flux de suies a permis d’appréhender l’impact d’une concentration massique inférieure. La réponse du capteur à ces différents flux de suies a été étudiée. Nous avons montré que la sensibilité et le temps de réponse du capteur sont optimaux pour une tension de polarisation donnée entre les deux électrodes dont la valeur dépend de la distribution en taille des suies. Ce phénomène a été expliqué par les propriétés électriques différentes des suies et modélisé par un équilibre entre accumulation et combustion par effet Joule des suies déposées permettant de simuler la réponse temporelle du capteurRoad transport contributes to a part of the particulate matter emissions, especially in big cities. Due to the negative effect of these pollutants on the human health and environment, more and more stringent emission standards for automotive are applied. These emissions are now limited in number of particles per kilometer and the vehicle need to indicate when there is some failure of the systems of depollution (OBD: On-Board diagnostic).Resistive sensors have shown good results to measure soot particles mass concentration. They have advantage of being a simple and robust technology that can be easily manufactured at a cheap price. The sensor principle consists of conductance measurement between two platinum electrodes. Conductance increases with soot deposition. This work aims to define the key parameters that affect the sensors response. Three particles flow with different particles size distributions (centered at 90, 70 and 50 nm) were used and characterized. A fourth flow was used to see the impact of a lower mass concentration. The sensor response exposed to these different flows was studied. It was shown that the sensor sensibility and response times are optimal for a given polarization voltage between the electrodes whose value depends on the size distribution. This phenomenon was explained by the different electrical properties of the soot particles and modeled by equilibrium of soot accumulation and their combustion by Joule heating that permitting to simulate the sensor temporal response
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Zia, Asim. "Cooperative and non-cooperative decision behaviors in response to the inspection and maintenance program in the Atlanta Airshed, 1997-2001." Diss., Available online, Georgia Institute of Technology, 2004:, 2004. http://etd.gatech.edu/theses/available/etd-07112004-211918/unrestricted/zia%5Fasim%5F200407%5Fphd.pdf.
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Thesis (Ph. D.)--School of Public Policy, Georgia Institute of Technology, 2005. Directed by Bryan Norton.Norton, Bryan, Committee Chair ; Rodgers, Michael, Committee Member ; Bozeman, Barry, Committee Member ; DeHart-Davis, Leisha, Committee Member ; Noonan, Douglas, Committee Member. Includes bibliographical references.
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Панченко, Ольга Вікторівна, Ольга Викторовна Панченко, Olha Viktorivna Panchenko, and М. В. Марин. "Еколого-економічні аспекти забруднення навколишнього природного середовища автотранспортом." Thesis, Сумський державний університет, 2017. http://essuir.sumdu.edu.ua/handle/123456789/64973.
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Автотранспорт як сектор економіки - один з основних чинників
антропогенного впливу на навколишнє природне середовище. Деякі види
цього впливу, особливо забруднення атмосферного повітря і підвищений
шум, відносяться до найбільших техногенних навантажень на довкілля.
Актуальність даної теми полягає в тому, що екологічна ситуація в Україні,
як i у всьому світі, перетворюється з несприятливої на кризову.
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Sun, Wai-choi Sunny, and 辛偉才. "A feasibility study of switching from the diesel to petrol light road transport to improve the urban air quality in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1995. http://hub.hku.hk/bib/B31253271.
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Choi, Ya-yin, and 蔡雅然. "A review of the control of motor vehicle fuel specifications and its effects on air quality." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B31255450.
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Lee, Chi-on, and 李子安. "Sustainable development and integrated transport planning: "Is Hong Kong moving towards a more sustainable transportsystem for new development areas?"." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31259959.
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Bennouna, Khalid. "Etude de l'emission et modelisation de la dispersion des polluants d'origine automobile." Paris 7, 1988. http://www.theses.fr/1988PA077011.
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Le but de ce travail est de connaitre la repartition spatio-temporelle des concentrations des polluants emis par les vehicules automobiles dans differents types de voierie (autoroute, route et rue encaissee), afin de determiner le niveau previsible de la pollution a laquelle est soumise la population
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Gao, Jing. "Etude et mise au point d'un capteur de gaz pour la detection sélective de NOx en pot d'échappement automobile." Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 2011. http://tel.archives-ouvertes.fr/tel-01016361.
Full textAbstract:
Afin de contrôler l'émission totale des NOx dans l'échappement automobile, un capteur potentiométrique à base de zircone stabilisée à l'yttrium a été développé par la technique de sérigraphie. Il est montré que l'utilisation d'un filtre catalytique, déposé directement sur l'élément sensible, permet d'éliminer les interférences venant d'autres gaz réducteurs dans l'échappement, en particulier monoxyde de carbone (CO), hydrogène (H2), hydrocarbures (CxHy) et ammoniac (NH3). En plus, il est possible de fixer avec le filtre catalytique le rapport NO/NO2 correspondant à l'équilibre thermodynamique. Par conséquent la réponse du capteur n'est plus dépendante du rapport NO/NO2, mais seulement de la température. De plus, la sensibilité et la sélectivité du capteur à NO2 peut considérablement être améliorée en appliquant un courant de polarisation.