Browse Topic: Environmental law
Stricter environmental legislation is driving ever-more-demanding performance targets for gasoline particulate filters (GPFs). This study constructs a multi-scale filtration model based on fractal characteristics, taking into account particle size distribution and particle deposition, to investigate the influence of the microstructure of porous media on GPF performance and analyze the impact of structural parameters on capture efficiency and pressure drop. The results show that: (1) Increasing the wall thickness can improve the capture efficiency and pressure drop, and a thicker wall has a stronger inertial interception capacity for larger particles. (2) A reduction in porosity markedly alters both filtration efficacy and flow pressure drop. For particles in the intermediate size range (0.1-0.5 μm), the capture efficiency of a low-porosity structure is more sensitive to the diffusion deposition of small particles, while the inertial collision efficiency of large particles is higher. (3) Shrinking the pore size markedly enhances capture efficiency while simultaneously increasing pressure drop; the finer pore network markedly improves the retention of sub-micron particles, but the passage restriction of large particles is more obvious.
Suppliers are learning several new and unwelcome lessons as the dynamics surrounding U.S. light vehicle trade and emissions legislation quickly shifts. Two major issues are at play here. As the industry continues to feel the impact of reduced or eliminated battery electric vehicle incentives in several North American and European jurisdictions and governments are retrenching on light vehicle emissions legislation - OEMs are questioning the size of the near- and mid-term market. Similarly, as of this writing, the saga surrounding future vehicle and parts tariffs between the U.S. and its major automotive trading partners continues. This unfortunate combination has driven OEMs to delay, extend and rescope future product programs. This jams a stick in the financial spokes of the supply base. Some context is in order. Like clockwork, in the highly competitive global light vehicle market, our industry was trained to expect a regular cadence for product renewals and product cycles. The combination of strong competition, emissions and safety regulations driving a constant stream of innovative technologies, and the need to improve fuel economy led the industry to adopt a regimented product cycle for most light vehicle segments. OEMs and suppliers alike assumed a 2.5-5-7.5-10-year cadence for future product revisions. This outlined that once an all-new vehicle was launched, one should expect a mid-cycle enhancement (MCE) at year 2.5 and a major revision at year 5. At year 7.5 another mid-cycle enhancement, then an all-new structure would follow for year 10. This sequence allowed for a healthy dose of new technology and styling to attract new/repeat customers and improve efficiency and an ever-stringent regulatory environment. While some vehicles strayed from this timing, most OEMs adopted it.
With the rapidly developing automotive industry and stricter environmental protection laws and regulations, lightweight materials, advanced manufacturing processes and structural optimization methods are widely used in body design. Therefore, in order to evaluate and improve the pedestrian protection during a collision, this paper presents an impact simulation modeling and structural optimization method for a sport utility vehicle engine hood made of carbon fiber reinforced plastic (CFRP). Head injury criterion (HIC) was used to evaluate the performance of the hood in this regard. The inner panel and the outer panel of CFRP hood were discretized by shell elements in LS_DYNA. The Mat54-55 card was used to define the mechanical properties of the CFRP hood. In order to reduce the computational costs, just the parts contacted with the hood were modeled. The simulations were done in the prescribed 30 impact points. In order to validate the reduced finite element model, pedestrian impact tests were carried out. To further improve the performance in terms of pedestrian safety, CFRP layers were added to strengthen the outer panel. A parametric optimization was carried out. Surrogate model was constructed by three approximation approaches and the errors were compared. Four algorithms were utilized to solve the optimization problem. The best optimization is done through Kriging model approximation and the non-dominated sorting genetic algorithm-the third version (NSGA-III). The optimal design is relatively light and reduces the HIC value of the critical point from 2397 to 876. This method can be a useful tool for pedestrian protection and related works.
Due to the large negative impact of combustion gas emissions on air quality and the more stringent environmental legislation, research on internal combustion engines (ICE) are being developed to reduce emissions of pollutant gases to the atmosphere. One of the research fronts is the use of lean mixtures with the pre-chamber ignition system (PCIS). This system consists of a pre-chamber (PC) connected to the main chamber by one or more interconnecting holes. A spark plug initiates combustion of the mixture present in the pre-chamber, which is propagated as gas jet into the main chamber, igniting the lean mixture present therein. The gas jets have high thermal and kinetic energy, which promote faster combustion duration, making the system less prone to knock and with lower cyclic variability of the IMEP, enabling the lean limit extension. The pre-chamber system can be assisted with a supplementary liquid or gaseous fuel injection, enabling the charge stratification. In this context, this paper aims to evaluate the reduction in exhaust emissions from an ICE adapted with a stratified PCIS operating with lean mixture (ethanol-air) in the main chamber and hydrogen injected directly into the pre-chamber. The tests were carried out on a Ford Sigma 1.6L engine operating at 2250 rpm and under an indicated effective mean pressure of 5bar. It was possible to identify that with the use of the pre-chamber ignition system, the lean limit of the mixture was extended to lambda 1.7 with low cyclic variability of the IMEP. If compared to the baseline engine, the PCIS prototype operating with lambda 1.7 showed reduction in volumetric exhaust emissions of 98.4% for NOx, 35.3% for HC, 69.9% for CO and 46.2% for CO2. These results allow to conclude that the use of PCIS to burn lean mixtures can promote significant reductions in exhaust gases emissions to the atmosphere.
Recently, it has been worth pointing out the relevance of alternative fuels in the improvement of air quality conditions and in the mitigation of global warming. In order to deal with these demands, in recent studies, it has been considered a great variety of alternative fuels. It goes without saying that the alternative fuels industry needs the best of the efficiency with a moderate layout. From this perspective, Liquefied Petroleum Gas (LPG) could represent a valid option, although it is not a renewable fuel. In terms of polluting emissions, the LPG can reduce nitrous oxides and smoke concentrations in the air, a capability that has a relevant importance for the modern pollution legislation. LPG is well known as an alternative fuel for Spark Ignition (SI) engines and, more recently, LPG systems have also been introduced in the Compression Ignition (CI) engines in dual-fuel configuration. In this research, LPG-Diesel liquid-blend has been used to power a CI engine in mixed fuel configuration. For this purpose, accurate modifications have been made on the single cylinder test ring and on the standard rail fuel injection system. LPG has been blended with diesel on the basis of the ratio 20-35% w/w. During the study, they have been carried out three sets of measurements: one by only using Diesel fuel and the others by using blended fuels at different engine operating conditions. The thermodynamic process, the combustion performance, and the exhaust emissions have been analyzed thanks to a specific designed-test campaign, with particular attention to the control strategies of fuel injection. The results show that, at partial load operating condition, Diesel-LPG blends improve the combustion and emission performances. In particular, it has been noticed, at constant Nitrogen Oxide (NOx), a significant decrease of particulate emissions. This observation confirms the previous authors’ results achieved on the optical engines.
Emissions of nitrogen oxides (NOx) from heavy-duty diesel engines are subject to more stringent environmental legislation. Selective catalytic reduction (SCR) over metal ion-exchanged zeolites is in this connection an efficient method to reduce NOx. Understanding durability of the SCR catalyst is crucial for correct design of the aftertreatment system. In the present paper, thermal and chemical ageing of Fe-BEA as NH3-SCR catalyst is studied. Experimental results of hydrothermal ageing, and chemical ageing due to phosphorous and potassium exposure are presented. The catalyst is characterized by flow reactor experiments, nitrogen physisorption, DRIFTS, XRD, and XPS. Based on the experimental results, a multisite kinetic model is developed to describe the activity of the fresh Fe-BEA catalyst. Furthermore, the model can predict deactivation of the catalyst well by decreasing the number of active sites, representing loss of active iron sites due to migration or chemical blockage of the sites. By performing a systematic study of different deactivation mechanisms, a deactivation expression for the active sites can be formulated.
New environmental legislation on emission and fuel efficiency targets increasingly requires good transient engine performance and this in turn means that the previously acceptable static engine calibration and control methodologies based on steady-state testing must be re-placed by dynamical optimization using dynamical models. Although many advances have been made in predictive models for internal combustion engines, the phenomena involved are so many, complex and nonlinear that dynamical black-box models typically employing neural network structures must be determined from system identification through experimental testing. Such identified dynamical models are required to provide high accuracy multiple step-ahead predictions of emissions but must accordingly also be compactly implementable for speed and memory to allow for the required large scale optimization involving possibly many thousands of iterations. This paper presents a novel methodology of using black box modeling techniques to build compact efficiently implementable nonlinear dynamic engine models with high predictive accuracy in the form of Neural Network and polynomial equations. The black box models obtained are shown to be efficient for state-of-the-art model-based fuel economy dynamical optimization with emission constraints. The effectiveness and relative efficiency of using polynomial models V.S. full Neural Network (NN) models in the fuel economy optimization are demonstrated. A novel multi-step ahead (simulation) output based parameter estimation method is proposed to improve the predictive accuracy of polynomial models.
Vehicular emissions limits have been reduced throughout the world in compliance with environmental legislations. With the rapid increase in the number of flex-fuel vehicles on the market, the consumption of ethanol has also increased. As a result, there is expected to be a large abundance of unburned alcohol from tailpipe gas emissions. Another important factor arising from the use of ethanol is the formation of tropospheric ozone. The objective of this study was to measure the amount of unburned alcohol and legislated emissions as well as the ozone formation potential of a passenger (light-duty) vehicle fueled with gasoline containing different concentrations of ethanol. The main conclusion is that unburned alcohol emissions increase in direct proportion to the ethanol content in the fuel. The unburned alcohol was measured by two techniques: gas chromatography and FTIR. Regarding ozone, it was concluded that ozone formation increases in direct proportion to the exposure of the exhaust gases to solar radiation and the ethanol content in the fuel.
The emergence of tougher environmental legislations and ever increasing demand for increased ride comfort, fuel efficiency, and low emissions have triggered exploration and advances towards more efficient vehicle gearbox technologies. The growing complexity and spatial distribution of such a mechatronic gearbox demands precise timing and coordination of the embedded electronics, integrated sensors and actuators as well as excellent overall reliability. The increased gearbox distributed systems have seen an increased dependence on sensors for feedback control, predominantly relying on hardware redundancy for faults diagnosis. However, the conventional hardware redundancy has disadvantages due to increased costs, weight, volume, power requirements and failure rates. This paper presents a virtual position sensor-based Fault Detection, Isolation and Accommodation (FDIA), which generates an analytical redundancy for comparison against the actual sensor output. The proposed FDIA scheme has been validated experimentally using an electro-hydraulic test rig and the gearshift simulation model, including the non-linear hydraulic actuator dynamics.
Several injection and ignition systems have been developed and tested since the invention of the internal combustion engine. As environmental regulations have become more stringent over the years, an electronic injection and ignition systems of the mixture air/fuel was implemented in the vehicles. Since then these systems have constantly been improved with the inclusion of devices, sensors and actuators that help them work more efficiently, both to gain power and for the enforcement of environmental laws in force in each country. For the correct operation of the engine electronic management it is extremely important to develop a software that can perfectly control the inputs (sensors) and outputs (actuators) information. The task of adjustment and calibration of the software requires a programmable module, which is connected to the vehicle and tested with various settings until an ideal fit between performance and emissions can be reached. This paper proposes the implementation of a programmable electronic management system that can replace the original system of the vehicle without exceeding the limits of pollutant emissions described in the Brazilian legislation. To achieve this goal, it will be necessary to analyze the behavior of the vehicle with its original management system and with the use of specific equipment such as the gas analyzer (emission pollutants), the automotive scanner (parameters of the management system) and the dynamometer (power and torque). Therefore this work presents the methodology, testing, advantages, disadvantages and limitations of implementing a programmable electronic management system for an internal combustion engine.
EU environmental law requires 30 ozone precursor volatile organic compounds (VOCs) to be measured for urban air quality control. In this study, 28 ozone precursor VOCs were measured at a rate of 0.5 Hz by an in-vehicle FTIR emission measurement system along with other VOCs. The vehicle used was a Euro 3 emission compliant diesel van. The test vehicle was started from a cold ambient temperature soak and driven under real world urban driving conditions. Diesel and B100 (100% Biodiesel) were compared using the same repeat journeys. The VOC emissions and OFP (ozone formation potential) were investigated as a function of engine warm up and ambient temperatures during cold start. The exhaust temperatures were measured along with the exhaust emissions. The temperature and duration of light off of the catalyst for VOC were monitored and showed a cold start period to catalyst light off that was considerably longer than would occur on the NEDC (New European Driving Cycle). The results showed that compounds that formed ozone were significantly higher in diesel exhausts and were higher than equivalent compounds in SI vehicles under cold start in real world urban driving. For B100 aldehyde emissions were higher than for diesel and this is a strong ozone forming gas. However, other VOCs that form ozone were lower than diesel. The higher VOCs with diesel compared to SI engines was mainly due to the oxidation catalyst not being active for much of the journey, whereas in SI engines VOC emissions were only significant during the cold start period. The results will also be shown to be dominated by transient events at junctions and by the cold start period
With the increase in fuel prices and the increasingly strict environmental legislations regarding CO₂ emissions, reduction of the total energy consumption of our society becomes more important. Passenger vehicles are partly responsible for this consumption due to their strong presence in the daily life of most people. Therefore reducing the impact of cars on the environment can assist in decreasing the overall energy consumption. Even though several fields have an impact on a passenger car's performance, this paper will focus on the aerodynamic part and more specifically, the wake behind a vehicle. By definition a car is a bluff body on which the air resistance is for the most part driven by pressure drag. This is caused by the wake these bodies create. Therefore analyzing the wake characteristics behind a vehicle is crucial if one would like to reduce drag. With the recent upgrade of wind tunnels with a moving belt system, the opportunity has emerged to investigate the flow field in the wake behind vehicles, matching closer the real on-road driving conditions. This study investigates experimentally and numerically the wake behind a passenger car of an SUV type. Three configurations with a significant change in CD have been chosen for the analysis. Their wake shape together with their respective closure points have been analyzed using three planes, namely one x-plane, one y-plane and one z-plane. Results have shown that the numerical simulations correlate well with the experiments in wake shape and wake behavior. However in the chosen configurations they underestimate the wake length. A distinct interference of the traversing unit presence can be noted in the experimental results.
Increasing competition in the automotive sector, according to new energy and environmental legislations, requires that the vehicles have higher performance with lower fuel consumption and pollutant emissions. These factors encourage the study of new technologies such as the Variable Valve Actuation System (VVA) in internal combustion engines. To accomplish this, a detailed study of friction and pumping losses present in the engine becomes relevant, as they directly influence its efficiency. According to Heywood [1], these losses vary in relation to the delivered energy from 10% at full load to 100% at idle, when there is no production of effective work. This paper proposes the application of combustion chamber pressure analysis to separately identify and measure the friction and pumping losses in engines with VVA.
Crankcase emissions are a complex mixture of combustion products and, specifically Particulate Matter (PM) from lubricant oil. Crankcase emissions contribute substantially to the particle mass and particle number (PN) emitted from an internal combustion engine. Environmental legislation demands that the combustion and crankcase emissions are either combined to give a total measurement or the crankcase gases are re-circulated back into the engine, both strategies require particle filtration. There is a lack of understanding regarding the physical processes that generate crankcase emissions of lubricant oil, specifically how the bulk lubricant oil is atomised into droplets. In this paper the crankcase of a motored compression ignition engine, has been optically accessed to visualise the lubricant oil distribution. The oil distribution was analysed in detail using high speed laser diagnostics, at engine speeds up to 2000 rpm and oil temperatures of 90°C. High resolution calibrated images show the passive behavior of lubricant oil once it has been supplied to critical engine components. The major mechanisms of oil atomisation have been identified and quantified from high speed images, the generation of oil droplets dp = 10 μm - 3 mm has been captured. The most significant generation mechanism was atomisation of oil films present on the surface of rotating components. The isolated contribution of the crank and camshafts to the atomised oil droplets present in the top of the engine has been recorded. Further breakup, evaporation and condensation from the surface of the atomised oil droplets will generate coarse and fine PM. Results from imaging data show good correlation with sub-micron PN sampling measurements captured in a previous study [1]; namely an increase in particle number concentration with increasing engine speed.
New combustion concepts developed in internal combustion engines such as homogeneous charge compression ignition (HCCI) have attracted serious attention due to the possibilities to simultaneously achieve higher efficiency and lower emissions, which will impact the environment positively. The HCCI combustion concept has potential of ultra-low NOX and particulate matter (PM) emission in comparison to a conventional gasoline or a diesel engine. Environmental Legislation Agencies are becoming increasingly concerned with particulate emissions from engines because the health and environmental effects of particulates emitted are now known and can be measured by sophisticated instruments. Particulate emissions from HCCI engines have been usually considered negligible, and the measurement of mass emission of PM from HCCI combustion systems shows their negligible contribution to PM mass. However some recent studies suggest that PM emissions from HCCI engines cannot be neglected. In this paper, effect of start of injection (SOI) of fuel on particulate emission of a HCCI engine fuelled with methanol is experimentally investigated. In this study, port fuel injection technique is used for preparing homogeneous mixture of methanol and air. The experiment is conducted with varying SOI timings for different amount of fuel, and intake air temperature. The engine exhaust particle sizer (EEPS) is used for size, surface area and volume distributions of soot particles emitted under each of these different operating conditions. It was found that total concentration of particles increase with increasing intake air temperature and particles are mainly in the size range from 10 to 150 nm. It was found that number and size distribution of HCCI generated soot particles depends on SOI, amount of fuel injected and the intake air temperature.
Due to the importance of fulfilling the actual and upcoming environmental legislation, it is an Airbus main target to develop eco-efficient materials. Under consideration of the economical effects, these processes will be implemented into the production line. This paper gives an overview of Airbus and its partners research work, the results obtained within the frame of the European funded, integrated technology demonstrator (ITD) ECO Design for Airframe. This ITD is part of the joint technology initiative Clean Sky. Developments with different grade of maturity from “upstream” as the investigation of materials from renewable recourses up to materials now in use in production as low volatile organic compounds cleaner are under investigation. As a basis for future eco-efficient developments an approach for a quantitative life cycle assessment will be demonstrated.
The strict regulation of environmental laws, the oil price and restricted resources has made the vehicle manufacturers to use other energy resources instead of fuel oil. Iran is recognized as the second holder of gas reservoirs in the world and can use hydrocarbon gases broadly in particular compressed natural gas (CNG) as the fuel for vehicles specifically in its public transportation fleet and thereby reduce the consumption of diesel fuel and gasoline. This will bring about the reduction of environmental pollutants and reduce the economic costs of transportation sector. With regard to the climatic situation of Iran and concerning the existence of broad network of gas distribution, CNG is a suitable alternative for other fuels. Therefore, developing bi-fuel engine (gasoline and CNG) in the short and middle term strategy for achieving this important subject will be necessary. A basic measure for supporting the subject is applied studies for considering and improving the engine performance. In this paper, a four-stroke bi-fuel spark ignition (SI) engine has been modeled. The model is based on the two-zone combustion model. The selective outputs are such as volumetric efficiency, brake power (BP), brake mean effective pressure (BMEP), torque, brake specific fuel consumption (BSFC) and emissions. In this study, the effect of engine speed, equivalence ratio and performance parameters have been discussed and considered. In addition, the model has been validated by experimental data of an engine performance result. The CNG with regard to the gaseous form specification has advantages and disadvantages as compared with gasoline. The natural gas forms a more homogenous mixture in comparison with gasoline. It is cheaper than gasoline and produces the least rate of CO while gasoline produces more power and less NOx as compared with CNG. In order to obtain an engine with less pollution and better performance, it should be designed for each type of fuels specifically.
New environmental legislation places increasing demands on automobile emission controls, requiring new approaches to engine management and diagnostics systems. This paper demonstrates the use of an Artificial Neural Network (ANN) solution for misfire detection in spark ignition engines. The solution is based on a truly parallel hardware implementation of an ANN. The network is developed by a data-driven training process, using data with known incidences of misfires. No analytical or algorithmic methods need to be developed in order to train or use the ANN for misfire detection. There is minimal processing overhead on the main processor of the engine management unit, freeing resources for alternative engine management tasks or enabling the use of less costly processor solutions.
Agricultural OEMs are looking at the total life cycle to develop more environmentally conscious products and processes. As environmental regulations become more stringent, agricultural OEMs have created environmental safeguards for their manufacturing plants and products as part of their overall marketing. They have incorporated environmental standards for controlling emissions from vehicles as well as manufacturing plants, recycling products at the end of their lives, and controlling hazardous wastes. They produce better designs for their combines and tractors to satisfy environmental regulations for fuels and emissions. They also make their vehicles more operator-friendly by reducing noise and in-cab pollution. “Customers for the most part want products that are environmentally friendly and place expectations on manufacturers to provide them,” said Mike Campbell, Product Development Manager for Caterpillar Ag Products, a subsidiary of Caterpillar Inc. “They do not share the same willingness to pay more for a product just because it's environmentally friendly. It's always a challenge to make such improvements cost-effective-recognizing that the value customers place on them will vary, both on an industry basis as well as a geographic basis. Traditionally, the U.S. and Europe have led the environmental effort. Tax credits are available to consumers who purchase products with lower emissions or sound levels. But as international standards are developed, this aspect will become less prevalent as the world continues to become a smaller place.”
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