Evaluation of Heavy-Duty Diesel Vehicle Emissions During Cold-Start and Steady-State Idling Conditions and Reduction of Emissions from a Truck-Stop Electrification Program

Cold-start and extended-idling emissions of carbon monoxide (CO), oxides of nitrogen (NOx) and particulate matter (PM) were measured from 24, class-8B, heavy-duty diesel vehicles (HDDV8B) using portable emission monitoring equipment. The ratio of nitrogen dioxide (NO2) to NOx and the ratio of PM2.5 to total PM were reported. Truck model years ranged from 1992 to 2004. All vehicles were tested in the field during summer and fall months under ambient environmental conditions at low (600-800 rpm) and high (1000 rpm) engine idling speeds with the truck cab air-conditioner operating at “on” and “off” modes. Sampling data thus obtained were used to generate typical average cold-start and extended-idling emission factors and were used to estimate potential emission reductions associated from using Truck Stop Electrification (TSE) Itechnology. Results indicated that cold-start emission rates, which were determined from the first 5-minutes of the cold-start period, were higher than the extended-idling emission rates by factors of 2.5 for CO, 1.5 for NOx and 1.7 for PM2.5. Overall, the extended-idling emission factors of the present study compared favorable to both the U.S Environmental Protection Agency (EPA) values that are recommended for State Implementation Plans (SIP) and average emission factors that were established from a previous review of the literature. In summary, the NOx emission rates were greater than those reported for EPA-SIP purposes and from the literature review by 23.5% and 17.4%, respectively. The PM2.5 emission rates observed in this study were less than those reported for EPA-SIP purposes by 3.8% and were greater than those reported in the literature by 6.3%, respectively. The average extended-idling emission factors for CO, NOx and PM2.5 were 64.5 g/hr, 167 g/hr and 3.51 g/hr, respectively. Electricity utilization and related emissions from TSE were calculated for a coal-fired power plant equipped with Selective Catalytic Reduction (SCR) technology for NOx removal and that meets New Source Performance Standards (NSPS) for NOx and PM2.5 emissions. In general, it was found that the cold-start emissions and the emissions from electricity were moderately small in comparison with the extended-idling emissions. Conversely, it was determined that the actual emission savings that could be associated with the TSE technology were 62.4 g/hr for CO, 158 g/hr for NOx and 3.19 g/hr for PM2.5. Finally, the corrected or actual emission reductions for CO, NOx and PM2.5 using a cold-start period for 5-minutes were approximately 3.2%, 5.0% and 10% less than the extended-idling emission rate, respectively

Analysis of particulate matter concentration and size distribution in heavy-duty vehicle exhaust emissions

This study put forward a method to predict the concentration field in the plume of a heavy-duty truck, operating at highway speed. It provided information regarding computation of dispersion coefficients in the area near a stack.;The numerical cumulative frequency fit method obtained in this study provided an effective and quick means for determining the particle size distribution parameters (the mass median aerodynamic diameters and geometric standard deviations) of sample data for the multi-modal distribution.;The particle size distribution of the compressed natural gas buses tested was characterized by a bi-modal particle size distribution; the clean diesel buses had a uni-modal particle size distribution.;The heavy-duty diesel trucks exhibited the Count Median Diameter (CMD) values ranging from 30 nm to 60 nm. EC-Diesel truck test yielded a CMD of 33 run (baseline), a CMD of 37--39 nm (with a JM-CRT), and a CMD of 40--47 nm (with a Engelhard DPX). CARB\u27s baseline was at 56 nm.;The thesis has 7 Chapters, 14 Tables, and 36 Figures

Liquid rocket engine turbines

Criteria for the design and development of turbines for rocket engines to meet specific performance, and installation requirements are summarized. The total design problem, and design elements are identified, and the current technology pertaining to these elements is described. Recommended practices for achieving a successful design are included

Data augmentation to improve the performance of ensemble learning for system failure prediction with limited observations

Ensemble learning has been widely used to improve the performance and robustness of machine learning algorithms on time series data. However, in real operational processes where the observed data is limited, it hinders the capability of ensemble learning algorithms. To address the challenge of limited observed data, this paper proposes a novel three-layer ensemble learning framework by use of data augmentation. Firstly, multiple classical time series augmentation methods are applied to increase the size of the data set. Subsequently, after pre-processing, these augmented data is trained by multiple basic learners with K-fold cross-validation as the first layer of the developed ensemble learning framework. The outputs of the first layer are integrated via LASSO to further improve the prediction performance, which serves as the second layer of the developed framework. Finally, the third-layer output is generated by averaging the prediction of the second layer and the output from an improved Long-Short Term Memory model that provides prediction based on the augmented data. A case study on a real wastewater treatment plant is used to illustrate the effectiveness of the proposed method

Improved Electric Vehicle Powertrain Incorporating a Lithium-Ion Battery and a Range Extender Zinc-Air Battery, plus Associated Health and Economic Benefits

As the world confronts the serious challenge posed by anthropogenic climate change, electric vehicles have emerged as a serious candidate to displace gasoline-burning vehicles. In spite of the environmental and operational advantages of electric vehicles, however, and in spite of billions in investment, electric vehicles have not attained meaningful market share in the main national vehicle markets. This is a serious problem not only for climate change mitigation but also for air pollution mitigation, given the substantial air pollution generated by vehicles. The inability of electric vehicles to attain market share may be due to the inadequacies of the lithium-ion batteries which power electric vehicles, and which are heavy and expensive. In this work an electric vehicle with a novel powertrain is designed, optimized and modelled. The novel powertrain uses a lithium-ion battery as the primary energy storage system and a lighter and cheaper zinc-air battery as a range extender. The first objective of this work is to compare this novel powertrain to a conventional electric vehicle powertrain and quantify the benefits. The optimized two-battery electric vehicle achieves 400 km of range, over 12 years of zinc-air battery life and an MSRP of $26,300 – over$5000 lower than that of the conventional electric vehicle. As part of this work, it is necessary to create a zinc-air cell model based on academic literature, since there are no commercially available rechargeable zinc-air cells that are suitable for use in vehicles. The cell model achieved 10% greater specific energy to the lithium-ion cell at a much lower price. An improved cell model achieved even greater specific energy – 65% greater than the lithium-ion cell. The second objective of this work is to analyze the air pollution impacts of electric vehicles in a local context. Specifically, the air pollution impact of increasing levels of electric vehicles on Highway 401 is simulated. Using Ontario Ministry of Transportation data for traffic flows on Highway 401, pollution modelling software and Transport Canada guidance it is estimated that pollution from Highway 401 costs $18.5M per year, and that replacing all the light passenger vehicles with electric vehicles could reduce these costs by 45.6%. The modelling demonstrates that NOx and PM2.5 are the costliest pollutants, and that PM2.5 experiences the least relative reduction in emissions with increased electric vehicle penetration

Aeronautical engineering: A continuing bibliography with indexes (supplement 257)

This bibliography lists 560 reports, articles, and other documents introduced into the NASA scientific and technical information system in September 1990. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics

Diesel exhaust: current knowledge of adverse effects and underlying cellular mechanisms

Diesel engine emissions are among the most prevalent anthropogenic pollutants worldwide, and with the growing popularity of diesel-fueled engines in the private transportation sector, they are becoming increasingly widespread in densely populated urban regions. However, a large number of toxicological studies clearly show that diesel engine emissions profoundly affect human health. Thus the interest in the molecular and cellular mechanisms underlying these effects is large, especially concerning the nature of the components of diesel exhaust responsible for the effects and how they could be eliminated from the exhaust. This review describes the fundamental properties of diesel exhaust as well as the human respiratory tract and concludes that adverse health effects of diesel exhaust not only emerge from its chemical composition, but also from the interplay between its physical properties, the physiological and cellular properties, and function of the human respiratory tract. Furthermore, the primary molecular and cellular mechanisms triggered by diesel exhaust exposure, as well as the fundamentals of the methods for toxicological testing of diesel exhaust toxicity, are described. The key aspects of adverse effects induced by diesel exhaust exposure described herein will be important for regulators to support or ban certain technologies or to legitimate incentives for the development of promising new technologies such as catalytic diesel particle filters

Aerosol jet deposition of samarium-doped ceria films

Direct write processes include a range of additive manufacturing technologies. These technologies are employed to fabricate structures by depositing layer upon layer of functional material. The feature resolutions obtained are often in the micron or sub-micron range. This thesis focuses on use of the Aerosol Jet direct write printing process, which shows promise for the fabrication of ceramic films due to its fine feature resolution and flexibility with printing complex features. This study identifies significant process parameters and their relationship to the process output for deposition of Samarium-doped Ceria (SDC) nano-ink. A design of experiments approach is used to generate a model where height and width of the printed tracks are the response variables of interest. Initial feasible operating ranges for each process parameter were identified. Then fractional factorial screening experiments were designed to identify the significant factors affecting the response variables in the study. Two distinct regression equations were generated to predict width and height. Validation experiments were run to confirm the actual values as compared with the predicted ones. For height, the experiment results suggested lack of curvature as well as the standard error and R-squared values were found satisfactory. For width, a higher order model was designed referring to the results of the validation experiment. For the higher order model a three factor three level experiment was considered. The higher order model gives a much lesser standard error and better fit of residuals as compared to the screening model for width. In addition, the study includes a brief discussion on use of Aerosol Jet printing system to manufacture high aspect ratio structures in addition to its application in thin film deposition. The work further demonstrates printing of a high aspect ratio micro-pillar array as a proof of this concept