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The increase of new and ever more stringent emission legislation has brought about with it a surge in the demand for more sustainable automotive solutions. This has particularly been the case for automobiles, including heavy-duty vehicles like trucks and buses, with internal combustion engines, which now require the design and manufacturing of more durable and reliable components. An important component of internal combustion engine automobiles, which helps achieve this target, is the exhaust after-treatment system. Exhaust after-treatment systems are usually equipped with some type of catalytic converter, treating the combustion gases from the engine exhaust manifold to reduce the concentration of pollutants. The catalytic converter assembly usually consists of an assembly of an outer metallic canning, an inner substrate and a packaging mat in between the two. The packaging mat, commonly known as the support mat, is an important component in the assembly, protecting the ceramic substrate from road induced and thermal loads, thereby preventing any damage to the latter. This thesis involves further development of a finite element model for the support mat that could be used in catalytic converter simulations with a reasonable degree of accuracy and reliability. In line with this objective, the characteristic mechanical response of the mat is first studied through a series of material tests: namely compression, friction, and shear tests. Different non-linear material models like hyperfoam, hyperelastic and viscoelastic models, are then created in ABAQUS to simulate the mat behaviour in the tests. The material model correlating most closely with the test is then implemented in the simulation of the assembly process, canning of a catalytic converter. This report includes the material tests conducted on the mats in new and aged condition, findings of the characteristic response of the mats in these tests as well as the constitutive material modelling and finite element s

The increase of new and ever more stringent emission legislation has brought about with it a surge in the demand for more sustainable automotive solutions. This has particularly been the case for automobiles, including heavy-duty vehicles like trucks and buses, with internal combustion engines, which now require the design and manufacturing of more durable and reliable components. An important component of internal combustion engine automobiles, which helps achieve this target, is the exhaust after-treatment system. Exhaust after-treatment systems are usually equipped with some type of catalytic converter, treating the combustion gases from the engine exhaust manifold to reduce the concentration of pollutants. The catalytic converter assembly usually consists of an assembly of an outer metallic canning, an inner substrate and a packaging mat in between the two. The packaging mat, commonly known as the support mat, is an important component in the assembly, protecting the ceramic substrate from road induced and thermal loads, thereby preventing any damage to the latter. This thesis involves further development of a finite element model for the support mat that could be used in catalytic converter simulations with a reasonable degree of accuracy and reliability. In line with this objective, the characteristic mechanical response of the mat is first studied through a series of material tests: namely compression, friction, and shear tests. Different non-linear material models like hyperfoam, hyperelastic and viscoelastic models, are then created in ABAQUS to simulate the mat behaviour in the tests. The material model correlating most closely with the test is then implemented in the simulation of the assembly process, canning of a catalytic converter. This report includes the material tests conducted on the mats in new and aged condition, findings of the characteristic response of the mats in these tests as well as the constitutive material modelling and finite element s

Chemicals produced by automobiles, such as low-level ozone and photochemical smog, were a major contributor to the pollution. Nitrogen oxides, carbonized hydrocarbons, and carbon monoxide are some of these hazardous gases that are harmful to both the environment and people. By transforming hazardous smoke into less hazardous gases, a catalytic converter purges the air of harmful substances. Typically, automobiles use catalytic converters that are simulated in this present work using ANSYS (Fluent). It is noted that the catalytic converter depends on its length, density, output pressure, and inlet velocity. Comparing the results to models of other catalytic converters, three planes, each with two oxidation and reduction blocks, produce better outcomes. This catalytic converter simulation transforms three toxic gases into less hazardous gases and works efficiently, in contrast to conventional catalytic converter models that only transform two dangerous gases.

Chemicals produced by automobiles, such as low-level ozone and photochemical smog, were a major contributor to the pollution. Nitrogen oxides, carbonized hydrocarbons, and carbon monoxide are some of these hazardous gases that are harmful to both the environment and people. By transforming hazardous smoke into less hazardous gases, a catalytic converter purges the air of harmful substances. Typically, automobiles use catalytic converters that are simulated in this present work using ANSYS (Fluent). It is noted that the catalytic converter depends on its length, density, output pressure, and inlet velocity. Comparing the results to models of other catalytic converters, three planes, each with two oxidation and reduction blocks, produce better outcomes. This catalytic converter simulation transforms three toxic gases into less hazardous gases and works efficiently, in contrast to conventional catalytic converter models that only transform two dangerous gases.

Catalytic converter is an important after treatment device for emission control in automobiles. Conversion rate of harmful exhaust emission gas in catalytic converter and its efficiency is directly related to design factors of converters such as catalyst materials, wash coat material, substrate material, substrate design and other design factors. Amongst all the factors selection of material for catalyst is considered to be the most important as it deals with exhaust molecules to form nontoxic exhaust emission like nitrogen, carbon dioxide, hydrogen and also it can result in reduction of back pressure by design optimization. Various materials have been used as catalyst for catalytic converter which ranges from precious metals like platinum, palladium and rhodium etc. to non-noble metals such as cobalt, zirconium etc. The selection of materials has greater significance in catalytic converter design because of the vast activity in material science. Therefore, the range of material available to engineers are much larger than ever before. To accomplish better performance at lower price requires as more rational process for material selection. This paper deals with the recent material selection methodology by using weighted property index method (WPIM) to select material for catalytic converter. The emission performance of a converter is primarily function of properties of the catalyst. So, in case of selecting catalytic material, there are different parameters that one might consider for catalyst selection. However, in this method five different important catalytic properties are selected as required characteristic which includes valency, density, ionization energy, thermal conductivity, and thermal expansion. They were optimized using WPIM. The results of the present paper on WPIM gives best material selection for converter. The selected material is again optimized by using cost per unit method and result shows best material by considering cost also for catalytic conve

Catalytic converter is an important after treatment device for emission control in automobiles. Conversion rate of harmful exhaust emission gas in catalytic converter and its efficiency is directly related to design factors of converters such as catalyst materials, wash coat material, substrate material, substrate design and other design factors. Amongst all the factors selection of material for catalyst is considered to be the most important as it deals with exhaust molecules to form nontoxic exhaust emission like nitrogen, carbon dioxide, hydrogen and also it can result in reduction of back pressure by design optimization. Various materials have been used as catalyst for catalytic converter which ranges from precious metals like platinum, palladium and rhodium etc. to non-noble metals such as cobalt, zirconium etc. The selection of materials has greater significance in catalytic converter design because of the vast activity in material science. Therefore, the range of material available to engineers are much larger than ever before. To accomplish better performance at lower price requires as more rational process for material selection. This paper deals with the recent material selection methodology by using weighted property index method (WPIM) to select material for catalytic converter. The emission performance of a converter is primarily function of properties of the catalyst. So, in case of selecting catalytic material, there are different parameters that one might consider for catalyst selection. However, in this method five different important catalytic properties are selected as required characteristic which includes valency, density, ionization energy, thermal conductivity, and thermal expansion. They were optimized using WPIM. The results of the present paper on WPIM gives best material selection for converter. The selected material is again optimized by using cost per unit method and result shows best material by considering cost also for catalytic conve

Catalytic converter is an important after treatment device for emission control in automobiles. Conversion rate of harmful exhaust emission gas in catalytic converter and its efficiency is directly related to design factors of converters such as catalyst materials, wash coat material, substrate material, substrate design and other design factors. Amongst all the factors selection of material for catalyst is considered to be the most important as it deals with exhaust molecules to form nontoxic exhaust emission like nitrogen, carbon dioxide, hydrogen and also it can result in reduction of back pressure by design optimization. Various materials have been used as catalyst for catalytic converter which ranges from precious metals like platinum, palladium and rhodium etc. to non-noble metals such as cobalt, zirconium etc. The selection of materials has greater significance in catalytic converter design because of the vast activity in material science. Therefore, the range of material available to engineers are much larger than ever before. To accomplish better performance at lower price requires as more rational process for material selection. This paper deals with the recent material selection methodology by using weighted property index method (WPIM) to select material for catalytic converter. The emission performance of a converter is primarily function of properties of the catalyst. So, in case of selecting catalytic material, there are different parameters that one might consider for catalyst selection. However, in this method five different important catalytic properties are selected as required characteristic which includes valency, density, ionization energy, thermal conductivity, and thermal expansion. They were optimized using WPIM. The results of the present paper on WPIM gives best material selection for converter. The selected material is again optimized by using cost per unit method and result shows best material by considering cost also for catalytic conve

Catalytic converter is an important after treatment device for emission control in automobiles. Conversion rate of harmful exhaust emission gas in catalytic converter and its efficiency is directly related to design factors of converters such as catalyst materials, wash coat material, substrate material, substrate design and other design factors. Amongst all the factors selection of material for catalyst is considered to be the most important as it deals with exhaust molecules to form nontoxic exhaust emission like nitrogen, carbon dioxide, hydrogen and also it can result in reduction of back pressure by design optimization. Various materials have been used as catalyst for catalytic converter which ranges from precious metals like platinum, palladium and rhodium etc. to non-noble metals such as cobalt, zirconium etc. The selection of materials has greater significance in catalytic converter design because of the vast activity in material science. Therefore, the range of material available to engineers are much larger than ever before. To accomplish better performance at lower price requires as more rational process for material selection. This paper deals with the recent material selection methodology by using weighted property index method (WPIM) to select material for catalytic converter. The emission performance of a converter is primarily function of properties of the catalyst. So, in case of selecting catalytic material, there are different parameters that one might consider for catalyst selection. However, in this method five different important catalytic properties are selected as required characteristic which includes valency, density, ionization energy, thermal conductivity, and thermal expansion. They were optimized using WPIM. The results of the present paper on WPIM gives best material selection for converter. The selected material is again optimized by using cost per unit method and result shows best material by considering cost also for catalytic conve

Catalytic converter is an important after treatment device for emission control in automobiles. Conversion rate of harmful exhaust emission gas in catalytic converter and its efficiency is directly related to design factors of converters such as catalyst materials, wash coat material, substrate material, substrate design and other design factors. Amongst all the factors selection of material for catalyst is considered to be the most important as it deals with exhaust molecules to form nontoxic exhaust emission like nitrogen, carbon dioxide, hydrogen and also it can result in reduction of back pressure by design optimization. Various materials have been used as catalyst for catalytic converter which ranges from precious metals like platinum, palladium and rhodium etc. to non-noble metals such as cobalt, zirconium etc. The selection of materials has greater significance in catalytic converter design because of the vast activity in material science. Therefore, the range of material available to engineers are much larger than ever before. To accomplish better performance at lower price requires as more rational process for material selection. This paper deals with the recent material selection methodology by using weighted property index method (WPIM) to select material for catalytic converter. The emission performance of a converter is primarily function of properties of the catalyst. So, in case of selecting catalytic material, there are different parameters that one might consider for catalyst selection. However, in this method five different important catalytic properties are selected as required characteristic which includes valency, density, ionization energy, thermal conductivity, and thermal expansion. They were optimized using WPIM. The results of the present paper on WPIM gives best material selection for converter. The selected material is again optimized by using cost per unit method and result shows best material by considering cost also for catalytic conve

Catalytic converter is an important after treatment device for emission control in automobiles. Conversion rate of harmful exhaust emission gas in catalytic converter and its efficiency is directly related to design factors of converters such as catalyst materials, wash coat material, substrate material, substrate design and other design factors. Amongst all the factors selection of material for catalyst is considered to be the most important as it deals with exhaust molecules to form nontoxic exhaust emission like nitrogen, carbon dioxide, hydrogen and also it can result in reduction of back pressure by design optimization. Various materials have been used as catalyst for catalytic converter which ranges from precious metals like platinum, palladium and rhodium etc. to non-noble metals such as cobalt, zirconium etc. The selection of materials has greater significance in catalytic converter design because of the vast activity in material science. Therefore, the range of material available to engineers are much larger than ever before. To accomplish better performance at lower price requires as more rational process for material selection. This paper deals with the recent material selection methodology by using weighted property index method (WPIM) to select material for catalytic converter. The emission performance of a converter is primarily function of properties of the catalyst. So, in case of selecting catalytic material, there are different parameters that one might consider for catalyst selection. However, in this method five different important catalytic properties are selected as required characteristic which includes valency, density, ionization energy, thermal conductivity, and thermal expansion. They were optimized using WPIM. The results of the present paper on WPIM gives best material selection for converter. The selected material is again optimized by using cost per unit method and result shows best material by considering cost also for catalytic conve

[EN] Worldwide pollutant regulations applied to the transportation sector are progressively tightening the emission limits and widening the operating conditions of the type approval tests. As a result, the layout and thermal management of the exhaust system is becoming highly complex looking to achieve early catalytic converter activation. On this regard, the monolith meso-geometry plays a primary role to optimise the pollutants con -version efficiency. The geometrical characteristics simultaneously affect and trade-off multiple flow phenomena as the exhaust gas is transported through the channels. These include the bulk gas and internal pore diffusion towards the active sites in addition to the heat transfer including convection, radial conductivity and thermal capacitance. In this work, the impacts of the cell size, cross-section shape, washcoat loading and substrate material on CO and HC conversion efficiency have been investigated under representative real driving condi-tions. From the real driving conditions experimental data, the study decouples the influence of the washcoat loading from the cell size and material applying a catalytic converter model. Detailed expressions are provided for the calculation of the specific surfaces and heat and mass transfer parameters as a function of the cell and washcoat meso-geometry in square and triangular cells. Therefore, this work enables to identify the processes which govern the catalytic abatement of pollutant emissions. In particular, the role of the gas and washcoat specific surfaces is highlighted because of its importance on the optimization of the mass transfer process by means of a proper cell geometry selection. In parallel, the differences in the change of the CO and HC abatement patterns, which are explained by the characteristic CO emission spikes in accelerations and the HC accumulation, contribute to evidence the limitations on the conversion efficiency benefit that the optimum cell geometry and washcoat l

Catalytic converter is an important after treatment device for emission control in automobiles. Conversion rate of harmful exhaust emission gas in catalytic converter and its efficiency is directly related to design factors of converters such as catalyst materials, wash coat material, substrate material, substrate design and other design factors. Amongst all the factors selection of material for catalyst is considered to be the most important as it deals with exhaust molecules to form nontoxic exhaust emission like nitrogen, carbon dioxide, hydrogen and also it can result in reduction of back pressure by design optimization. Various materials have been used as catalyst for catalytic converter which ranges from precious metals like platinum, palladium and rhodium etc. to non-noble metals such as cobalt, zirconium etc. The selection of materials has greater significance in catalytic converter design because of the vast activity in material science. Therefore, the range of material available to engineers are much larger than ever before. To accomplish better performance at lower price requires as more rational process for material selection. This paper deals with the recent material selection methodology by using weighted property index method (WPIM) to select material for catalytic converter. The emission performance of a converter is primarily function of properties of the catalyst. So, in case of selecting catalytic material, there are different parameters that one might consider for catalyst selection. However, in this method five different important catalytic properties are selected as required characteristic which includes valency, density, ionization energy, thermal conductivity, and thermal expansion. They were optimized using WPIM. The results of the present paper on WPIM gives best material selection for converter. The selected material is again optimized by using cost per unit method and result shows best material by considering cost also for catalytic conve

[ES] Debido al aumento de la contaminación de los automóviles, la industria automovilistica ha incluido convertidores catalíticos en sus tubos de escape. Pero el comportamiento de flujo dentro del monolito catalítico y en el difusor afecta altamente al rendimiento y la eficiencia de estos sistemas. En este estudio se ha aplicado a esta configuración un análisis CFD a través del software OpenFOAM. El modelo de turbulencia v2f se ha utilizado para la evaluación de las condiciones de flujo constante y transitorio. Además, cada una de las condiciones de flujo se ha analizado en mallado 2D y en otro 3D. Los resultados para el flujo constante se han validado respecto los datos medidos por la técnica HWA (Hot wire Anemometry). Se ha encontrado que la configuración con la malla 3D captura mejor el flujo en la primera parte de la distancia lateral mientras que la malla 2D captura mejor el segundo pico de velocidad. Finalmente, con respecto a los resultados del flujo pulsado, se han comparado los contornos de velocidad para ambos casos, dándose cuenta de que son similares., [EN] Due to the increase of cars pollution, the automotive industry has included catalytic converters to its exhaust gases in the vehicles. But the flow behavior inside of he catalytic monolith and in the diffuser affects highly to the performance and efficiency of this systems. In this study a CFD analysis through the software OpenFOAM has been applied to this configuration. The v2f turbulence model have been used for the assessment of the steady and transient flow conditions. Moreover, each flow conditions have been analyzed in a 2D mesh and a 3D one. The results for the steady flow have been validated against a measured data by the HWA (Hot wire Anemometry) technique. It has been found that the configuration with the 3D mesh capture better the flow bwhviour in the first part of the lateral distance while the 2D mesh capture better the second peak of velocity. Finally, regarding the pulsating flow results the velocity contours for both cases have been compared realizing that they are similar.

[EN] The acoustic modelling of exhaust after-treatment devices, such as catalytic converters (CC) and diesel particulate filters (DPF), usually requires the use of multidimensional numerical techniques to assess the influence of higher order modes on the sound attenuation performance. Three-dimensional (3D) wave propagation can be considered through the finite element method (FEM). With a view to improving the computational expenditure of full 3D FEM, an efficient modelling technique is presented in this work to speed up transmission loss (TL) calculations in after-treatment devices with arbitrary cross section incorporating monoliths. The efficient modelling approach is based on the mode matching method, combining: (1) transversal pressure modes computed through a 2D FEM approach for devices with arbitrary but axially uniform cross section; (2) compatibility conditions of the acoustic fields at the device geometric discontinuities. For the acoustic modelling of monoliths, these are replaced by four pole transfer matrices relating the acoustic fields at both sides of the monolithic region. Mode matching TL results are compared with full 3D FE simulations and experimental measurements for some selected configurations, showing a good agreement. For a given accuracy, the computational efficiency of the mode matching technique proposed in this work improves that of full 3D FE calculations. TL improvements are achieved by suitable locations of a DPF inlet/outlet ducts. Next, a Genetic Algorithm (GA)-based optimization approach is used in order to improve the attenuation performance of the after-treatment device by varying the geometry as well as the monolith properties. Results show that the optimized configuration outperforms the initial design at target frequencies.

[EN] The acoustic modelling of exhaust after-treatment devices, such as catalytic converters (CC) and diesel particulate filters (DPF), usually requires the use of multidimensional numerical techniques to assess the influence of higher order modes on the sound attenuation performance. Three-dimensional (3D) wave propagation can be considered through the finite element method (FEM). With a view to improving the computational expenditure of full 3D FEM, an efficient modelling technique is presented in this work to speed up transmission loss (TL) calculations in after-treatment devices with arbitrary cross section incorporating monoliths. The efficient modelling approach is based on the mode matching method, combining: (1) transversal pressure modes computed through a 2D FEM approach for devices with arbitrary but axially uniform cross section; (2) compatibility conditions of the acoustic fields at the device geometric discontinuities. For the acoustic modelling of monoliths, these are replaced by four pole transfer matrices relating the acoustic fields at both sides of the monolithic region. Mode matching TL results are compared with full 3D FE simulations and experimental measurements for some selected configurations, showing a good agreement. For a given accuracy, the computational efficiency of the mode matching technique proposed in this work improves that of full 3D FE calculations. TL improvements are achieved by suitable locations of a DPF inlet/outlet ducts. Next, a Genetic Algorithm (GA)-based optimization approach is used in order to improve the attenuation performance of the after-treatment device by varying the geometry as well as the monolith properties. Results show that the optimized configuration outperforms the initial design at target frequencies.

[ES] Debido al aumento de la contaminación de los automóviles, la industria automovilistica ha incluido convertidores catalíticos en sus tubos de escape. Pero el comportamiento de flujo dentro del monolito catalítico y en el difusor afecta altamente al rendimiento y la eficiencia de estos sistemas. En este estudio se ha aplicado a esta configuración un análisis CFD a través del software OpenFOAM. El modelo de turbulencia v2f se ha utilizado para la evaluación de las condiciones de flujo constante y transitorio. Además, cada una de las condiciones de flujo se ha analizado en mallado 2D y en otro 3D. Los resultados para el flujo constante se han validado respecto los datos medidos por la técnica HWA (Hot wire Anemometry). Se ha encontrado que la configuración con la malla 3D captura mejor el flujo en la primera parte de la distancia lateral mientras que la malla 2D captura mejor el segundo pico de velocidad. Finalmente, con respecto a los resultados del flujo pulsado, se han comparado los contornos de velocidad para ambos casos, dándose cuenta de que son similares., [EN] Due to the increase of cars pollution, the automotive industry has included catalytic converters to its exhaust gases in the vehicles. But the flow behavior inside of he catalytic monolith and in the diffuser affects highly to the performance and efficiency of this systems. In this study a CFD analysis through the software OpenFOAM has been applied to this configuration. The v2f turbulence model have been used for the assessment of the steady and transient flow conditions. Moreover, each flow conditions have been analyzed in a 2D mesh and a 3D one. The results for the steady flow have been validated against a measured data by the HWA (Hot wire Anemometry) technique. It has been found that the configuration with the 3D mesh capture better the flow bwhviour in the first part of the lateral distance while the 2D mesh capture better the second peak of velocity. Finally, regarding the pulsating flow results the velocity contours for both cases have been compared realizing that they are similar.

[EN] The acoustic modelling of exhaust after-treatment devices, such as catalytic converters (CC) and diesel particulate filters (DPF), usually requires the use of multidimensional numerical techniques to assess the influence of higher order modes on the sound attenuation performance. Three-dimensional (3D) wave propagation can be considered through the finite element method (FEM). With a view to improving the computational expenditure of full 3D FEM, an efficient modelling technique is presented in this work to speed up transmission loss (TL) calculations in after-treatment devices with arbitrary cross section incorporating monoliths. The efficient modelling approach is based on the mode matching method, combining: (1) transversal pressure modes computed through a 2D FEM approach for devices with arbitrary but axially uniform cross section; (2) compatibility conditions of the acoustic fields at the device geometric discontinuities. For the acoustic modelling of monoliths, these are replaced by four pole transfer matrices relating the acoustic fields at both sides of the monolithic region. Mode matching TL results are compared with full 3D FE simulations and experimental measurements for some selected configurations, showing a good agreement. For a given accuracy, the computational efficiency of the mode matching technique proposed in this work improves that of full 3D FE calculations. TL improvements are achieved by suitable locations of a DPF inlet/outlet ducts. Next, a Genetic Algorithm (GA)-based optimization approach is used in order to improve the attenuation performance of the after-treatment device by varying the geometry as well as the monolith properties. Results show that the optimized configuration outperforms the initial design at target frequencies.

[ES] Debido al aumento de la contaminación de los automóviles, la industria automovilistica ha incluido convertidores catalíticos en sus tubos de escape. Pero el comportamiento de flujo dentro del monolito catalítico y en el difusor afecta altamente al rendimiento y la eficiencia de estos sistemas. En este estudio se ha aplicado a esta configuración un análisis CFD a través del software OpenFOAM. El modelo de turbulencia v2f se ha utilizado para la evaluación de las condiciones de flujo constante y transitorio. Además, cada una de las condiciones de flujo se ha analizado en mallado 2D y en otro 3D. Los resultados para el flujo constante se han validado respecto los datos medidos por la técnica HWA (Hot wire Anemometry). Se ha encontrado que la configuración con la malla 3D captura mejor el flujo en la primera parte de la distancia lateral mientras que la malla 2D captura mejor el segundo pico de velocidad. Finalmente, con respecto a los resultados del flujo pulsado, se han comparado los contornos de velocidad para ambos casos, dándose cuenta de que son similares., [EN] Due to the increase of cars pollution, the automotive industry has included catalytic converters to its exhaust gases in the vehicles. But the flow behavior inside of he catalytic monolith and in the diffuser affects highly to the performance and efficiency of this systems. In this study a CFD analysis through the software OpenFOAM has been applied to this configuration. The v2f turbulence model have been used for the assessment of the steady and transient flow conditions. Moreover, each flow conditions have been analyzed in a 2D mesh and a 3D one. The results for the steady flow have been validated against a measured data by the HWA (Hot wire Anemometry) technique. It has been found that the configuration with the 3D mesh capture better the flow bwhviour in the first part of the lateral distance while the 2D mesh capture better the second peak of velocity. Finally, regarding the pulsating flow results the velocity contours for both cases have been compared realizing that they are similar.

[ES] Debido al aumento de la contaminación de los automóviles, la industria automovilistica ha incluido convertidores catalíticos en sus tubos de escape. Pero el comportamiento de flujo dentro del monolito catalítico y en el difusor afecta altamente al rendimiento y la eficiencia de estos sistemas. En este estudio se ha aplicado a esta configuración un análisis CFD a través del software OpenFOAM. El modelo de turbulencia v2f se ha utilizado para la evaluación de las condiciones de flujo constante y transitorio. Además, cada una de las condiciones de flujo se ha analizado en mallado 2D y en otro 3D. Los resultados para el flujo constante se han validado respecto los datos medidos por la técnica HWA (Hot wire Anemometry). Se ha encontrado que la configuración con la malla 3D captura mejor el flujo en la primera parte de la distancia lateral mientras que la malla 2D captura mejor el segundo pico de velocidad. Finalmente, con respecto a los resultados del flujo pulsado, se han comparado los contornos de velocidad para ambos casos, dándose cuenta de que son similares., [EN] Due to the increase of cars pollution, the automotive industry has included catalytic converters to its exhaust gases in the vehicles. But the flow behavior inside of he catalytic monolith and in the diffuser affects highly to the performance and efficiency of this systems. In this study a CFD analysis through the software OpenFOAM has been applied to this configuration. The v2f turbulence model have been used for the assessment of the steady and transient flow conditions. Moreover, each flow conditions have been analyzed in a 2D mesh and a 3D one. The results for the steady flow have been validated against a measured data by the HWA (Hot wire Anemometry) technique. It has been found that the configuration with the 3D mesh capture better the flow bwhviour in the first part of the lateral distance while the 2D mesh capture better the second peak of velocity. Finally, regarding the pulsating flow results the velocity contours for both cases have been compared realizing that they are similar.

Transportation emissions are the highest contributor to air pollution, which is around 85%. One technology that can be used to reduce exhaust emissions from transportation is by installing a catalytic converter in the exhaust emission exhaust system. This study discusses the use of catalytic converters to reduce carbon monoxide (CO) and hydrocarbons (HC) with variations in engine speed and fuel. The catalyst used is a three-way catalytic converter model. The engine speed used is idle, 1000 rpm, 1500 rpm, 2000 rpm, 2500 rpm, 3000 rpm, 3500 rpm. The variations in the fuel used are pertalite, pertamax and pertamax turbo. The use of catalytic converters can reduce the concentration of CO and HC with all three types of fuel. The biggest reduction in CO and HC concentrations reached 39.5% and 22.7%. From this study, it can be seen that the use of catalytic converters can reduce exhaust emissions. The greater the octane number of the fuel, the less CO and HC emissions contained in the exhaust gas. The use of catalytic converters can be a solution to overcome the problem of pollution caused by transportation equipment because of its ability to convert hazardous compounds to exhaust emissions into harmless gases.

To mitigate the concentrations of air pollutants in the atmosphere, an intervention program of replacing the converters of liquefied petroleum gas (LPG) fueled vehicles was implemented by the Hong Kong government between October 2013 and April 2014. Data of ambient volatile organic compounds (VOCs) and other trace gases continuously monitored from September 2012 to April 2017 at a roadside site were used to evaluate the continuous effectiveness of the replaced catalytic converters on the reduction of air pollutants. The measurement data showed that LPG-related VOCs (propane and n/i-butanes) and several trace gases (CO, NO and NO2) decreased significantly from before to after the program (p < 0.01). To further assess the efficiency of the program, five periods covering before the program, during the program, 1st year after the program, 2nd year after the program and 3rd year after the program were categorized. The values of propane and n/i-butanes decreased from Period-1 (before the program) to Period-2 (during the program), and from Period-2 to Periods 3–5 (after the program) (p < 0.01). In addition, the reduction rates of propane and n/i-butanes remained high and constant in Periods 3–5, suggesting that either had the vehicle owners themselves routinely replaced the converters at suitable interval afterwards, or were their vehicles caught by a remote sensing program checking excessive emissions. Source apportionment analysis indicated that LPG-fueled vehicular emissions were the top contributor to ambient VOCs in the roadside environment while the VOCs emitted from LPG-fueled vehicles indeed decreased at a rate of 4.21 ± 2.38 ppbv/year (average ± 95% confidence interval) from Period-1 to Period-5 (p < 0.01). Furthermore, the photochemical box model simulations revealed that the net negative contribution of VOCs and NOx emitted from LPG-fueled vehicles to O3 production strengthened at a rate of 1.9 × 10−2 pptv/day from

Transportation emissions are the highest contributor to air pollution, which is around 85%. One technology that can be used to reduce exhaust emissions from transportation is by installing a catalytic converter in the exhaust emission exhaust system. This study discusses the use of catalytic converters to reduce carbon monoxide (CO) and hydrocarbons (HC) with variations in engine speed and fuel. The catalyst used is a three-way catalytic converter model. The engine speed used is idle, 1000 rpm, 1500 rpm, 2000 rpm, 2500 rpm, 3000 rpm, 3500 rpm. The variations in the fuel used are pertalite, pertamax and pertamax turbo. The use of catalytic converters can reduce the concentration of CO and HC with all three types of fuel. The biggest reduction in CO and HC concentrations reached 39.5% and 22.7%. From this study, it can be seen that the use of catalytic converters can reduce exhaust emissions. The greater the octane number of the fuel, the less CO and HC emissions contained in the exhaust gas. The use of catalytic converters can be a solution to overcome the problem of pollution caused by transportation equipment because of its ability to convert hazardous compounds to exhaust emissions into harmless gases.

Transportation emissions are the highest contributor to air pollution, which is around 85%. One technology that can be used to reduce exhaust emissions from transportation is by installing a catalytic converter in the exhaust emission exhaust system. This study discusses the use of catalytic converters to reduce carbon monoxide (CO) and hydrocarbons (HC) with variations in engine speed and fuel. The catalyst used is a three-way catalytic converter model. The engine speed used is idle, 1000 rpm, 1500 rpm, 2000 rpm, 2500 rpm, 3000 rpm, 3500 rpm. The variations in the fuel used are pertalite, pertamax and pertamax turbo. The use of catalytic converters can reduce the concentration of CO and HC with all three types of fuel. The biggest reduction in CO and HC concentrations reached 39.5% and 22.7%. From this study, it can be seen that the use of catalytic converters can reduce exhaust emissions. The greater the octane number of the fuel, the less CO and HC emissions contained in the exhaust gas. The use of catalytic converters can be a solution to overcome the problem of pollution caused by transportation equipment because of its ability to convert hazardous compounds to exhaust emissions into harmless gases.

Transportation emissions are the highest contributor to air pollution, which is around 85%. One technology that can be used to reduce exhaust emissions from transportation is by installing a catalytic converter in the exhaust emission exhaust system. This study discusses the use of catalytic converters to reduce carbon monoxide (CO) and hydrocarbons (HC) with variations in engine speed and fuel. The catalyst used is a three-way catalytic converter model. The engine speed used is idle, 1000 rpm, 1500 rpm, 2000 rpm, 2500 rpm, 3000 rpm, 3500 rpm. The variations in the fuel used are pertalite, pertamax and pertamax turbo. The use of catalytic converters can reduce the concentration of CO and HC with all three types of fuel. The biggest reduction in CO and HC concentrations reached 39.5% and 22.7%. From this study, it can be seen that the use of catalytic converters can reduce exhaust emissions. The greater the octane number of the fuel, the less CO and HC emissions contained in the exhaust gas. The use of catalytic converters can be a solution to overcome the problem of pollution caused by transportation equipment because of its ability to convert hazardous compounds to exhaust emissions into harmless gases.

Transportation emissions are the highest contributor to air pollution, which is around 85%. One technology that can be used to reduce exhaust emissions from transportation is by installing a catalytic converter in the exhaust emission exhaust system. This study discusses the use of catalytic converters to reduce carbon monoxide (CO) and hydrocarbons (HC) with variations in engine speed and fuel. The catalyst used is a three-way catalytic converter model. The engine speed used is idle, 1000 rpm, 1500 rpm, 2000 rpm, 2500 rpm, 3000 rpm, 3500 rpm. The variations in the fuel used are pertalite, pertamax and pertamax turbo. The use of catalytic converters can reduce the concentration of CO and HC with all three types of fuel. The biggest reduction in CO and HC concentrations reached 39.5% and 22.7%. From this study, it can be seen that the use of catalytic converters can reduce exhaust emissions. The greater the octane number of the fuel, the less CO and HC emissions contained in the exhaust gas. The use of catalytic converters can be a solution to overcome the problem of pollution caused by transportation equipment because of its ability to convert hazardous compounds to exhaust emissions into harmless gases.

This special issue of Topics in Catalysis gathers the proceedings of the 11th International Congress on Catalysis and Automotive Pollution Control (CAPoC11) held at the Université Libre de Bruxelles from October 29th to 31st 2018. Since the first edition in 1986, automotive pollution control by catalysis has rapidly developed to become one of the most active and popular areas of applied research in heterogeneous catalysis. More recently, after the disclosure of illegal practices with “defeat devices”, the abatement of automotive pollutants is of topmost importance for current and future generations of scientists and engineers in both academia and industry. This was demonstrated clearly in view of the 220 participants from 31 countries gathering in Brussels during CAPoC11. The nearly balanced attendance of academia and industry was the guarantee for many fruitful discussions about issues of fundamental and applied character. It is the organizers’ firm conviction that the synergetic interaction of its attending protagonists is key to the success of CAPoC meetings and, more generally, to the improvement of catalysis-based technology for emission control.As did its ten predecessors, CAPoC11 was demonstrated to be an efficient platform to discuss recent scientific and technological advances in different topics related to applications and requirements of catalysis in duty automotive emission control, especially the following topics:Catalyst and sorption technologies;Particulate emission control for both diesel and gasoline engines;After treatment for gaseous HC, H2 and renewable or reformulated fuel mixtures;Emission control for natural-gas, dual-fuel engines and hybrid vehicles;Off-cycles emissions and unregulated pollutants;Materials for catalysts, washcoat and fuel-borne catalysts;Modelling of after treatment systems and catalyst characterization;Integrated emission control systems, on-board diagnostics;Sustainable fuel technologies;Innovative technologies (new materia, info:eu-repo/semantics/published

Дипломний проект, пояснювальна записка 107с., 42 рисунка, 44 таблиці, 35 джерел. Газоаналізатор оксиду вуглецю в атмосферному повітрі, для моніторингу екологічної ситуації в міській та приміській зонах. Обрано електрохімічний метод. Робота газоаналізатора заснована на вимірюванні сили струму, який генерується трьохелектродним електрохімічним сенсором. Застосовані: спеціальна система корегування нуля завдяки каталітичному конвертору, електропневматичний клапан, сенсор, компресор, цифрова обробка сигналів, вивід інформації на РКІ та аналогові прилади. Вимірювання концентрації оксиду вуглецю в межах від 0 до 50,0 мг/м3., In the Diploma project, explanatory message is 107 pages, 42 pictures, 44 tables, 35 sources. A gas analyzer of carbon monoxide in atmospheric air, for monitoring of ecological situation in city and suburban areas. An electrochemical method is select. Work of gas analyzer is based on measuring of strength of current which is generated three-electrode electrochemical sensor. Applied: special system of updating zero due to a catalytic converter, electro-pneumatic valve, touch-control, compressor, digital treatment of signals, conclusion of information is on LCD and analog devices. There is measuring of concentration of carbon monoxide scope from 0 to 50,0 mg/m3.

Exhaust gas in motorized vehicles is the main source of air pollution in the environment. Pollution of motor vehicle exhaust can be reduced by paying attention to the maintenance system, modern engine control concepts, fuel cleaning, and reduction of exhaust emissions. Catalytic converters are the most effective tool to fight pollutants in our environment because they reduce nearly 80 % of the harmful gases that result from incomplete combustion of the engine. To find out the flow phenomena that occur, a simulation of the pattern of exhaust gas flow is made with variations in the number and shape of the Catalytic converter filter. This research begins with the making of a Catalytic converter design which includes: filter­not­cut and filter­cut dimensions. Then design the frame dimensions of the Catalytic converter with a variety of filters: 2, 3, 4 and 5 pieces and do the simulation. The simulation results show that the increase in speed percentage is caused by the exhaust gas flow passing through the small holes in the filter so that the gas pressure changes to an increase in speed. Installation of 2 filter­not­cut pieces is recommended because there is no vacuum area. The addition of the number of filters increases the vacuum area that occurs, this is related to the durability of the Catalytic converter. The simulation results suggest using the 3 most durable filter­cut pieces compared to using filters: 2, 4 and 5 pieces. In filter­not­cut (3, 4 and 5 pieces), the random pressure distribution is caused by the non­uniform pressure. This non­uniform flow decreases the efficiency and durability of the Catalytic converter. Unlike the case with 3 filter­cut pieces that have a more regular pressure distribution, are more solid and fused, Вихлопні гази автомобілів є основним джерелом забруднення повітря в навколишньому середовищі. Забруднення вихлопними газами автомобілів може бути скорочено якщо приділяти увагу системі технічного обслуговування, сучасним концепціям управління двигуном, очищенню палива і скороченню викидів вихлопних газів. Каталітичні нейтралізатори є найбільш ефективним інструментом боротьби з забрудненням навколишнього середовища, оскільки вони скорочують майже 80% шкідливих газів, що утворюються в результаті неповного згоряння в двигуні. Для з'ясування явищ, що протікають, проведено моделювання структури потоку вихлопних газів зі зміною кількості і форми фільтра каталітичного нейтралізатора. Дане дослідження починається зі створення конструкції каталітичного нейтралізатора, яка включає в себе: розміри нерозрізаного фільтра і розміри розрізаного фільтра. Потім конструюються розміри рами каталітичного нейтралізатора з різною кількістю фільтрів: 2, 3, 4 і 5 штук і виконується моделювання. Результати моделювання показують, що збільшення відсотка швидкості обумовлено потоком вихлопних газів, що проходить через невеликі отвори в фільтрі, таким чином тиск газу впливає на збільшення швидкості. Рекомендується встановлювати 2 нерозрізаних фільтра, оскільки вакуумна зона відсутня. Збільшення кількості фільтрів збільшує площу вакууму, що пов'язано з довговічністю каталітичного нейтралізатора. Результати моделювання передбачають використання 3 найбільш довговічних розрізаних фільтрів в порівнянні з використанням 2, 4 і 5 фільтрів. У нерозрізаних фільтрах (3, 4 і 5 штук) випадковий розподіл тиску обумовлений нерівномірним тиском. Цей нерівномірний потік знижує ефективність і довговічність каталітичного нейтралізатора. На відміну від випадку з 3 розрізаними фільтрами, які мають більш рівномірний розподіл тиску, більш тверді і сплавлені, Выхлопные газы автомобилей являются основным источником загрязнения воздуха в окружающей среде. Загрязнение выхлопными газами автомобилей может быть сокращено если уделять внимание системе технического обслуживания, современным концепциям управления двигателем, очистке топлива и сокращению выбросов выхлопных газов. Каталитические нейтрализаторы являются наиболее эффективным инструментом борьбы с загрязнением окружающей среды, поскольку они сокращают почти 80% вредных газов, образующихся в результате неполного сгорания в двигателе. Для выяснения протекающих явлений, проведено моделирование структуры потока выхлопных газов с изменением количества и формы фильтра каталитического нейтрализатора. Данное исследование начинается с создания конструкции каталитического нейтрализатора, которая включает в себя: размеры неразрезанного фильтра и размеры разрезанного фильтра. Затем конструируются размеры рамы каталитического нейтрализатора с различным колличеством фильтров: 2, 3, 4 и 5 штук и выполняется моделирование. Результаты моделирования показывают, что увеличение процента скорости обусловлено потоком выхлопных газов, проходящим через небольшие отверстия в фильтре, таким образом давление газа влияет на увеличение скорости. Рекомендуется устанавливать 2 неразрезанных фильтра, поскольку вакуумная зона отсутствует. Увеличение количества фильтров увеличивает площадь вакуума, что связано с долговечностью каталитического нейтрализатора. Результаты моделирования предполагают использование 3 наиболее долговечных разрезанных фильтров по сравнению с использованием 2, 4 и 5 фильтров. В неразрезанных фильтрах (3, 4 и 5 штук) случайное распределение давления обусловлено неравномерным давлением. Этот неравномерный поток снижает эффективность и долговечность каталитического нейтрализатора. В отличие от случая с 3 разрезанными фильтрами, которые имеют более равномерное распределение давления, более твердые и сплавлены

[EN] The acoustic modelling of automotive exhaust devices, such as catalytic converters (CC) and diesel particulate filters (DPF), usually requires the use of multidimensional analytical and numerical techniques. The presence of higher order modes and three-dimensional waves in the expansion and contraction subdomains, as well as sound propagation within the monolith capillary ducts, can be considered through the finite element method (FEM), although this approach is traditionally thought to be very time consuming. With a view to overcome this limitation and to reduce the computational effort of the FEM, alternative modelling techniques are presented in the current work to speed up transmission loss calculations in exhaust devices incorporating monoliths. These approaches are based on the point collocation technique and the mode matching method. As shown in earlier studies, the sound attenuation of an exhaust device incorporating a monolith can be properly predicted if the latter is replaced by a plane wave four-pole transfer matrix providing a relationship between the acoustic fields at both sides of the monolithic region. Therefore, this work combines the presence of multidimensional higher order modes in the expansion and contraction regions with one-dimensional wave propagation within the capillary ducts of the central monolith. The point collocation technique and the mode matching method are applied to the compatibility conditions of the acoustic fields at all the subdomain interfaces to couple the solutions of the wave equation in the corresponding exhaust device subcomponents. For the particular case of rigid circular ducts, Bessel functions are considered as transversal pressure modes. The computational efficiency and accuracy of the results associated with the two analytical modelling techniques presented here are assessed, including the effect of the number of modes and collocation points, as well as their location. All the analytical approaches proposed i

[EN] The acoustic modelling of automotive exhaust devices, such as catalytic converters (CC) and diesel particulate filters (DPF), usually requires the use of multidimensional analytical and numerical techniques. The presence of higher order modes and three-dimensional waves in the expansion and contraction subdomains, as well as sound propagation within the monolith capillary ducts, can be considered through the finite element method (FEM), although this approach is traditionally thought to be very time consuming. With a view to overcome this limitation and to reduce the computational effort of the FEM, alternative modelling techniques are presented in the current work to speed up transmission loss calculations in exhaust devices incorporating monoliths. These approaches are based on the point collocation technique and the mode matching method. As shown in earlier studies, the sound attenuation of an exhaust device incorporating a monolith can be properly predicted if the latter is replaced by a plane wave four-pole transfer matrix providing a relationship between the acoustic fields at both sides of the monolithic region. Therefore, this work combines the presence of multidimensional higher order modes in the expansion and contraction regions with one-dimensional wave propagation within the capillary ducts of the central monolith. The point collocation technique and the mode matching method are applied to the compatibility conditions of the acoustic fields at all the subdomain interfaces to couple the solutions of the wave equation in the corresponding exhaust device subcomponents. For the particular case of rigid circular ducts, Bessel functions are considered as transversal pressure modes. The computational efficiency and accuracy of the results associated with the two analytical modelling techniques presented here are assessed, including the effect of the number of modes and collocation points, as well as their location. All the analytical approaches proposed i

This thesis work has been conducted in the Handheld Laboratory at Husqvarna AB with the purpose of finding the parameters responsible for the performance of the catalytic converters used in the test rig. The catalytic converters are used in the test rig during the long term testing of the chain saws to reduce the hydrocarbon content from the exhaust before it enters into the environment. To perform this research two approaches were carried out. One with Design of Experiment (DOE) and another using Scanning Electron Microscope (SEM) analysis. In Design of Experiments parameters that are suspected to be influencing the performance of the catalytic converter were refined. Using these parameters a test plan is made with the help of statistical analysis application Minitab and the tests were carried out in the test rig. Using SEM the effects of aging and its effect on microstructure and chemical composition on the catalyst surface was analyzed. The results from the DoE shows that the exhaust flow, collector diameter and distance to the muffler are responsible for the collection of exhaust. Distance to the muffler and collector length are the factors affecting the conversion of the exhaust. In addition to that exhaust flow is also responsible for the duration of heating coil running time. The results from the SEM analysis shows that the operating temperature is high due to which there is thermal degradation of catalyst and there is also deactivation due to fouling. Another finding is that the flow on to the catalyst is not uniformly distributed

This thesis work has been conducted in the Handheld Laboratory at Husqvarna AB with the purpose of finding the parameters responsible for the performance of the catalytic converters used in the test rig. The catalytic converters are used in the test rig during the long term testing of the chain saws to reduce the hydrocarbon content from the exhaust before it enters into the environment. To perform this research two approaches were carried out. One with Design of Experiment (DOE) and another using Scanning Electron Microscope (SEM) analysis. In Design of Experiments parameters that are suspected to be influencing the performance of the catalytic converter were refined. Using these parameters a test plan is made with the help of statistical analysis application Minitab and the tests were carried out in the test rig. Using SEM the effects of aging and its effect on microstructure and chemical composition on the catalyst surface was analyzed. The results from the DoE shows that the exhaust flow, collector diameter and distance to the muffler are responsible for the collection of exhaust. Distance to the muffler and collector length are the factors affecting the conversion of the exhaust. In addition to that exhaust flow is also responsible for the duration of heating coil running time. The results from the SEM analysis shows that the operating temperature is high due to which there is thermal degradation of catalyst and there is also deactivation due to fouling. Another finding is that the flow on to the catalyst is not uniformly distributed

My dissertation addresses how engineers, scientists, and bureaucrats generated knowledge about pollution, crafted an institution for environmental protection, and constructed a collective identity for themselves. I show an important shift in regulators\' priorities, from stringent health-based standards to flexible technology-based ones through the development of end-of-pipeline pollution control devices, which contributed to the emergence of economic incentives and voluntary management programs. Drawing on findings from archival documents, published sources, and oral history interviews, I examine the first decade of the EPA amid constant organizational changes that shaped the technological and managerial character of environmental policy in the United States. Exploring the EPA\'s internal research and development processes and their relationship with scientific and engineering communities sheds light on how the new fields of environmental engineering and policy were co-produced in the 1970s. I argue that two competing approaches for environmental management, a community health approach and a control technology approach, developed from EPA\'s responses to bureaucratic, geographical, and epistemic challenges. I focus on researchers and managers from the Office of Research and Development at Research Triangle Park, North Carolina, as they were engaged in (1) controversy about integrated aerometry and epidemiology research intended to correlate air pollution and health, (2) intra-agency debate about the government\'s responsibility for introducing catalytic converters for tailpipe emissions reduction and responding to the potential environmental and social consequences, and (3) inter-agency activities for the demonstration of scrubbers for smokestack emissions and further application of the control technology approach in energy-related environmental problems. My principal conceptual contribution is "regulatory engineering." I define regulatory engineering as an approac

The life cycle analysis compares the environmental impacts of catalytic converters and the effects of not using these devices. To environmentally evaluate the catalytic converter, the emissions during extraction, processing, use of the product are considered. All relevant materials and energy supplies are evaluated for the catalytic converter. The goal of this life cycle is to compare the pollutants of a car with and without a catalytic converter. Pollutants examined are carbon monoxide (CO), carbon dioxide (CO2), hydrocarbons (HC), and nitrogen oxides (NOx). The main finding is that even considering materials and processing, a catalytic converter decreases the CO, HC and NOx pollutant emissions. The CO2 emissions are increased with a catalytic converter, but this increase is small relative to the overall CO2 emissions. The majority of catalytic converter pollutants are caused by the use phase, not extraction or processing. The life cycle analysis indicates that a catalytic converter decreases damage to human health by almost half, and the ecosystem quality damage is decreased by more than half. There is no damage to resources without a converter, as there are no materials or energy required; the damages with a converter are so small that they are not a significant factor. Overall, catalytic converters can be seen as worthwhile environmental products when considering short term effects like human health effects of smog, which are their design intent. If broader environmental perspectives that include climate change are considered, then the benefits depend on the weighting of these different environmental impacts.

[[abstract]]本文主要目的在針對機車引擎冷車起動過程，探討二次空氣對觸媒轉換器及污染改善的影響。探討引擎溫車暫態和熱車穩態過程，與怠速及高轉速運轉狀況下之污染排放和觸媒轉換器溫度變化。在冷起動暫態下，引擎及觸媒轉換器均未達工作溫度，此時的汙染是非常嚴重的，故實驗利用高壓引進各種二次空氣流量，使污染排放廢氣能夠繼續燃燒，除了可以降低污染排放CO及HC外，還可以提高污染排放的溫度，使其能快速加熱觸媒轉換器和含氧感知器，提早達到工作溫度，提高觸媒轉換器轉換效率與減少污染排放。 本實驗使用主動式二次空氣，以光陽KYMCO奔騰G5 Fi 噴射引擎為測試車體，以電子方式來控制二次空氣流量，分別以10、20、30、40、50 L/min，導入汽缸頭旁的排氣歧管，藉此讓燃燒不完全的廢氣再繼續燃燒。如此可將燃燒不完全的HC和CO繼續燃燒，而且可同時加熱排氣管裡的氧化觸媒和含氧感知器，減少HC和CO的汙染排放。 經由一系列的實驗測試獲得結果為，主動式二次空氣比被動式二次空氣更能夠減低CO及HC的排放，但需要有大量的二次空氣對機車引擎污染排放CO及HC才有良好的淨化效果。在熱車實驗了解到，二次空氣流量在20 L/min以上，能夠有效同時改善CO、HC的排放量；在冷車實驗了解到，主動式二次空氣流量越大越能夠改善HC的排放量，而CO的排放量，只有在30 L/min以上，才有明顯的改善, [[abstract]]This paper is mainly to discuss the effect of secondary air in motorcycles to the exhaust pollution and catalytic converter during the engine warm-up period. We measured the exhaust emissions and catalytic converter’s temperature during engine warm-up and the idle/high engine speed. Under the warm-up transient condition, the engine and catalytic converter are both not reach the working temperature. The pollution during this period is heavy. So in this experiment, we controlled different flows of high-pressure’s secondary air into the exhaust pipe to make exhaust emission to burn continuously. This operation will lower the amount of CO and HC in exhaust, it also can make exhaust temperature higher to heat the catalytic converter and oxygen sensor rapidly.The converting efficiency of the catalytic converter was improved and the exhaust pollution was reduced. In this experiment we used active secondary air and the test engine is G5 Fi engine of KYMCO company. The secondary air flow was controlled electronically. The high-pressure secondary air into exhaust manifold near the cylinder head was controlled with the amount of 10、20、30、40、50 L/min respectively. By this method, the exhaust continue to burn the HC and CO in exhaust pipe. Then the emission to the environment was reduced. Through a series of experiments, we found that the operation of the active secondary air is better than the passive one to lower the CO and HC amount in exhaust. But it needs large amount of active secondary air to reduce the CO and HC in exhaust. In the experiment under the stable operation of engine, we found that if the secondary air amount is over 20 L/min, it can reduce the CO and HC amount in exhaust at the same time. If under the warm-up operation of engine, we found that the larger amount the secondary air is, the lower amount the HC in exhaust. But the amount of CO only reduce obviously when the secondary air is over 30 L/min

There is a scarcity of data on which decisions can be based regarding the limitation of idling during standstill periods. There is also reason to believe that the significance of engine management during standstill may vary between different propulsion systems and technical standards etc, which will increase the need for a decision base. The need for data that describe exhaust emissions during crawling speed is particularly great in the case of tunnels. Ventilation plants in tunnels are designed on the basis of relationships between emissions and mean speed. Up till now, for speeds below 30 km/h, these relationships have not been satisfactorily based on measured data. The primary objective has been to fill the gaps in knowledge by exhaust measurements. The methodology has comprised a survey of the literature, measurements and analyses. Different objectives result in different limiting times for idling during standstill periods. For the vehicle fleet as a whole, different limits have been estimated for different objectives: for private economy, 12 seconds; for macro economy overall, 23 seconds; for energy policy, 12 seconds, and for air quality, 36 seconds. There are also time limits per compound, per technical standard and per vehicle type. The time for diesel is shorter than for petrol engine. According to measurements, emission of oxides of nitrogen (NOx) at crawling speed varies over the range -51 and 171% for different engine types when speed drops from 25 to 10 km/h. There are considerable differences in the speed dependence of fuel consumption both between and within studies. The relationships which could be estimated for particulate emissions do not, in any one case, indicate an increase in emission as speed drops from 25 km/h.

Avgasmängden som bensindrivna fordon tillåts släppa ut minskas hela tiden. Ett sätt att möta framtida krav, är att förbättra katalysatorns effektivitet. För att göra detta kan luft-bränsle-förhållandet regleras med avseende på syrelagringen i katalysatorn, istället för som idag, reglera mot stökiometriskt blandningsförhållande. Eftersom syrelagringen inte går att mäta med en givare behövs en modell som beskriver katalysatorns dynamiska egenskaper. Tre sådana modeller har undersökts, utvärderats och jämförts. Två av modellerna har implementerats i Matlab/Simulink och anpassats till mätningar från en experimentuppställning. För att kunna observera syrelagringen online valdes slutligen en av modellerna ut, och implementerades i ett Extended Kalman filter. Ytterligare arbete behöver läggas ner på den mest lovande modellen, och detsamma gäller för Kalmanfiltret, men på sikt förväntas resultaten kunna bli bra., The legal amount of emissions that vehicles with spark ignited engines are allowed to produce are steadily reduced over time. To meet future emission requirements it is desirable to make the catalytic converter work in a more efficient way. One way to do this is to control the air-fuel-ratio according to the oxygen storage level in the converter, instead of, as is done today, always trying to keep it close to stoichiometric. The oxygen storage level cannot be measured by a sensor. Hence, a model describing the dynamic behaviors of the converter is needed to observe this level. Three such models have been examined, validated, and compared. Two of these models have been implemented in Matlab/Simulink and adapted to measurements from an experimental setup. Finally, one of the models was chosen to be incorporated in an extended Kalman filter (EKF), in order to make it possible to observe the oxygen storage level online. The model that shows best potential needs further work, and the EKF is working with flaws, but overall the results are promising.

There is a scarcity of data on which decisions can be based regarding the limitation of idling during standstill periods. There is also reason to believe that the significance of engine management during standstill may vary between different propulsion systems and technical standards etc, which will increase the need for a decision base. The need for data that describe exhaust emissions during crawling speed is particularly great in the case of tunnels. Ventilation plants in tunnels are designed on the basis of relationships between emissions and mean speed. Up till now, for speeds below 30 km/h, these relationships have not been satisfactorily based on measured data. The primary objective has been to fill the gaps in knowledge by exhaust measurements. The methodology has comprised a survey of the literature, measurements and analyses. Different objectives result in different limiting times for idling during standstill periods. For the vehicle fleet as a whole, different limits have been estimated for different objectives: for private economy, 12 seconds; for macro economy overall, 23 seconds; for energy policy, 12 seconds, and for air quality, 36 seconds. There are also time limits per compound, per technical standard and per vehicle type. The time for diesel is shorter than for petrol engine. According to measurements, emission of oxides of nitrogen (NOx) at crawling speed varies over the range -51 and 171% for different engine types when speed drops from 25 to 10 km/h. There are considerable differences in the speed dependence of fuel consumption both between and within studies. The relationships which could be estimated for particulate emissions do not, in any one case, indicate an increase in emission as speed drops from 25 km/h.

Avgasmängden som bensindrivna fordon tillåts släppa ut minskas hela tiden. Ett sätt att möta framtida krav, är att förbättra katalysatorns effektivitet. För att göra detta kan luft-bränsle-förhållandet regleras med avseende på syrelagringen i katalysatorn, istället för som idag, reglera mot stökiometriskt blandningsförhållande. Eftersom syrelagringen inte går att mäta med en givare behövs en modell som beskriver katalysatorns dynamiska egenskaper. Tre sådana modeller har undersökts, utvärderats och jämförts. Två av modellerna har implementerats i Matlab/Simulink och anpassats till mätningar från en experimentuppställning. För att kunna observera syrelagringen online valdes slutligen en av modellerna ut, och implementerades i ett Extended Kalman filter. Ytterligare arbete behöver läggas ner på den mest lovande modellen, och detsamma gäller för Kalmanfiltret, men på sikt förväntas resultaten kunna bli bra., The legal amount of emissions that vehicles with spark ignited engines are allowed to produce are steadily reduced over time. To meet future emission requirements it is desirable to make the catalytic converter work in a more efficient way. One way to do this is to control the air-fuel-ratio according to the oxygen storage level in the converter, instead of, as is done today, always trying to keep it close to stoichiometric. The oxygen storage level cannot be measured by a sensor. Hence, a model describing the dynamic behaviors of the converter is needed to observe this level. Three such models have been examined, validated, and compared. Two of these models have been implemented in Matlab/Simulink and adapted to measurements from an experimental setup. Finally, one of the models was chosen to be incorporated in an extended Kalman filter (EKF), in order to make it possible to observe the oxygen storage level online. The model that shows best potential needs further work, and the EKF is working with flaws, but overall the results are promising.

There is a scarcity of data on which decisions can be based regarding the limitation of idling during standstill periods. There is also reason to believe that the significance of engine management during standstill may vary between different propulsion systems and technical standards etc, which will increase the need for a decision base. The need for data that describe exhaust emissions during crawling speed is particularly great in the case of tunnels. Ventilation plants in tunnels are designed on the basis of relationships between emissions and mean speed. Up till now, for speeds below 30 km/h, these relationships have not been satisfactorily based on measured data. The primary objective has been to fill the gaps in knowledge by exhaust measurements. The methodology has comprised a survey of the literature, measurements and analyses. Different objectives result in different limiting times for idling during standstill periods. For the vehicle fleet as a whole, different limits have been estimated for different objectives: for private economy, 12 seconds; for macro economy overall, 23 seconds; for energy policy, 12 seconds, and for air quality, 36 seconds. There are also time limits per compound, per technical standard and per vehicle type. The time for diesel is shorter than for petrol engine. According to measurements, emission of oxides of nitrogen (NOx) at crawling speed varies over the range -51 and 171% for different engine types when speed drops from 25 to 10 km/h. There are considerable differences in the speed dependence of fuel consumption both between and within studies. The relationships which could be estimated for particulate emissions do not, in any one case, indicate an increase in emission as speed drops from 25 km/h.

Bränsleförbrukning, utsläpp av kväveoxider (NOx) och kolväten (HC) från en bensindriven personbil med katalysator mättes on-the-road för tre trafikmiljöer. Mätsystemet, som utvecklats vid VTI, omfattar bl.a. analysinstrument för gasformiga föroreningar, bränsleflödesmätare, temperaturmätning (olja, kylvatten, bränsle etc., totalt åtta mätpunkter) samt registrering av tid och sträcka. Inverkan på emissioner och bränsleförbrukning av vägtyp och kall start kartlades. Distanserna för de tre körförloppen representerande Centrumområde, Ytterområde och Motorväg var respektive 16,7 km, 20,1 km och 31,5 km. Sträckningarna valdes för att spegla nämnda trafikmönster. Kväveoxidbildning gynnas av den goda (fullständiga) förbränning som följer av hög och jämn motorbelastning. Detta bekräftas av att NOx-utsläppen i förhållande till avverkad sträcka (g/km NOx) ökar i ordningsföljd: Centrumområde, Ytterområde, Motorväg. Kolväten och kolmonoxid däremot, oxideras (till koldioxid och vatten) vid fullständig förbränning vilket illustreras av parallellt avtagande HC-utsläpp. Uppmätt bränsleförbrukning minskar i ordning: Centrumområde, Motorväg, Ytterområde, vilket bekräftar gängse data, dvs. att den specifika bränsleförbrukningen stiger med ökande hastighet i det övre hastighetsområdet. Den aktuella studien behandlar även komplettering av det ombordinstrumenterade avgas- /bränslemätsystemet med en bredbandig ë-sond, samt två IR-instrument för mätning av CO2 och höga CO-värden respektive av låga CO-värden., Fuel consumption, emissions of nitrogen oxides (NOx) and hydrocarbons (HC) for a gasoline passenger car with catalyst were measured on-the-road for three driving patterns. The on board measurement system developed at VTI includes analyzers for gaseous pollutants, fuel flow metering, temperature registration (oil, cooling water, fuel etc., total eight cases) as well as logging of time and distance. Effects on emissions and fuel consumption of road type and of cold start were studied. Distances of the three traffic types representing City centre, Intermediate area and Motorway were respectively 16.7 km, 20.1 km and 31.5 km. They were chosen to reflect the traffic patterns mentioned. Nitrogen oxides formation is favoured by the good (complete) combustion resulting from high and constant engine load. This is borne out by NOx emissions vs. mileage rising in order: City centre, Intermediate, Motorway. Hydrocarbons and carbon monoxide, on the contrary, are oxidized (to form carbon dioxide and water) by complete combustion, as illustrated by HC declining in the same sequence. Fuel consumption decreasing according to City centre, Intermediate, Motorway corroborates prevalent data to the effect that specific fuel consumption is seen to increase with speed in the high speed range. The report also describes extending of the fuel/pollutant measurement instrumentation with a broadband alpha-sensor and IR analyzers for monitoring of CO2 and high range CO and of low range CO.

Bränsleförbrukning, utsläpp av kväveoxider (NOx) och kolväten (HC) från en bensindriven personbil med katalysator mättes on-the-road för tre trafikmiljöer. Mätsystemet, som utvecklats vid VTI, omfattar bl.a. analysinstrument för gasformiga föroreningar, bränsleflödesmätare, temperaturmätning (olja, kylvatten, bränsle etc., totalt åtta mätpunkter) samt registrering av tid och sträcka. Inverkan på emissioner och bränsleförbrukning av vägtyp och kall start kartlades. Distanserna för de tre körförloppen representerande Centrumområde, Ytterområde och Motorväg var respektive 16,7 km, 20,1 km och 31,5 km. Sträckningarna valdes för att spegla nämnda trafikmönster. Kväveoxidbildning gynnas av den goda (fullständiga) förbränning som följer av hög och jämn motorbelastning. Detta bekräftas av att NOx-utsläppen i förhållande till avverkad sträcka (g/km NOx) ökar i ordningsföljd: Centrumområde, Ytterområde, Motorväg. Kolväten och kolmonoxid däremot, oxideras (till koldioxid och vatten) vid fullständig förbränning vilket illustreras av parallellt avtagande HC-utsläpp. Uppmätt bränsleförbrukning minskar i ordning: Centrumområde, Motorväg, Ytterområde, vilket bekräftar gängse data, dvs. att den specifika bränsleförbrukningen stiger med ökande hastighet i det övre hastighetsområdet. Den aktuella studien behandlar även komplettering av det ombordinstrumenterade avgas- /bränslemätsystemet med en bredbandig ë-sond, samt två IR-instrument för mätning av CO2 och höga CO-värden respektive av låga CO-värden., Fuel consumption, emissions of nitrogen oxides (NOx) and hydrocarbons (HC) for a gasoline passenger car with catalyst were measured on-the-road for three driving patterns. The on board measurement system developed at VTI includes analyzers for gaseous pollutants, fuel flow metering, temperature registration (oil, cooling water, fuel etc., total eight cases) as well as logging of time and distance. Effects on emissions and fuel consumption of road type and of cold start were studied. Distances of the three traffic types representing City centre, Intermediate area and Motorway were respectively 16.7 km, 20.1 km and 31.5 km. They were chosen to reflect the traffic patterns mentioned. Nitrogen oxides formation is favoured by the good (complete) combustion resulting from high and constant engine load. This is borne out by NOx emissions vs. mileage rising in order: City centre, Intermediate, Motorway. Hydrocarbons and carbon monoxide, on the contrary, are oxidized (to form carbon dioxide and water) by complete combustion, as illustrated by HC declining in the same sequence. Fuel consumption decreasing according to City centre, Intermediate, Motorway corroborates prevalent data to the effect that specific fuel consumption is seen to increase with speed in the high speed range. The report also describes extending of the fuel/pollutant measurement instrumentation with a broadband alpha-sensor and IR analyzers for monitoring of CO2 and high range CO and of low range CO.

Extra exhaust emissions after short, 10 to 60 minutes, engine stops appear not to approach zero linearly as the stop time goes to zero. Particularly large deviations are those of nitrogen oxide (NOx) and particulates for cars without as well as with catalyst. Extra NOx emissions for catalyst cars are higher for 1 h stop time than both for shorter and longer stop time. Large systematic variations in emission levels were confirmed for extended driving distance during dynamometer runs also after a 23 km warm-up. From this follows that the NOx reduction with time estimated in national inventories, if these circumstances are considered, can be expected to decrease.

Extra exhaust emissions after short, 10 to 60 minutes, engine stops appear not to approach zero linearly as the stop time goes to zero. Particularly large deviations are those of nitrogen oxide (NOx) and particulates for cars without as well as with catalyst. Extra NOx emissions for catalyst cars are higher for 1 h stop time than both for shorter and longer stop time. Large systematic variations in emission levels were confirmed for extended driving distance during dynamometer runs also after a 23 km warm-up. From this follows that the NOx reduction with time estimated in national inventories, if these circumstances are considered, can be expected to decrease.

I en av VTI utvecklad beräkningsmodell för beskrivning av kallstarteffekter från bilar,COLDSTART, ingår beskrivning av temperaturutveckling i bensindrivna motorer. Mot denna bak-grund har funktioner utvecklats för beskrivning av motortemperatur under körning, under parkeringoch under uppvärmning med elektrisk motorvärmare. Fem bensindrivna bilar, varav två med katalysator, har utrustats med temperaturgivare i kyl-vattnet, i oljan och i katalysatorn. En 9 km lång mätslinga, tätortsmiljö, har innehållit hastighetsbe-gränsningar både till 50 och 70 km/h. Parallellt med temperaturmätning har i vissa fall även av-gaser registrerats. För de studerade delarna av motorn gäller följande: att det under körning tar minst 0,3 h innan samtliga delar är fullt uppvärmda att det för avstängd motor tar minst 1,3 h innan temperaturen i samtliga delar halverats att det tar minst 0,6 h för en motorvärmare att höja kylvattentemperaturen 50% av denmaximala höjningen.

I en av VTI utvecklad beräkningsmodell för beskrivning av kallstarteffekter från bilar,COLDSTART, ingår beskrivning av temperaturutveckling i bensindrivna motorer. Mot denna bak-grund har funktioner utvecklats för beskrivning av motortemperatur under körning, under parkeringoch under uppvärmning med elektrisk motorvärmare. Fem bensindrivna bilar, varav två med katalysator, har utrustats med temperaturgivare i kyl-vattnet, i oljan och i katalysatorn. En 9 km lång mätslinga, tätortsmiljö, har innehållit hastighetsbe-gränsningar både till 50 och 70 km/h. Parallellt med temperaturmätning har i vissa fall även av-gaser registrerats. För de studerade delarna av motorn gäller följande: att det under körning tar minst 0,3 h innan samtliga delar är fullt uppvärmda att det för avstängd motor tar minst 1,3 h innan temperaturen i samtliga delar halverats att det tar minst 0,6 h för en motorvärmare att höja kylvattentemperaturen 50% av denmaximala höjningen.