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As the efforts to push capabilities of current engine hardware to their durability limits increases, more accurate and reliable analysis is necessary to ensure that designs are robust. This paper evaluates a method of Conjugate Heat Transfer (CHT) analysis for a gasoline and a diesel engine that combines combustion Computational Fluid Dynamics (CFD), engine Finite Element Analysis (FEA), and cooling jacket CFD with the goal of obtaining more accurate temperature distribution and heat loss predictions in an engine compared to standard de-coupled CFD and FEA analysis methods. This novel CHT technique was successfully applied to a 2.5 liter GM LHU gasoline engine at 3000 rpm and a 15.0 liter Cummins ISX heavy duty diesel engine operating at 1250 rpm. Combustion CFD simulations results for the gasoline and diesel engines are validated with the experimental data for cylinder pressure and heat release rate.

General agreement exists that the ultimate goals of traffic accident research are to reduce fatality, mitigate injury and decrease economic loss to society. Although massive quantities of data have been collected in local, national and international programs, attempts by analysts to use these data to explore ideas or support hypotheses have been met by a variety of problems. Specifically, the coded variables in the different files are not consistent and little information on accident etiology is collected. Examples of the inadequacies of present data in terms of the collected and coded variables are shown. The vehicular, environmental and human (consisting of human factors and injury factors) variables are disproportionately represented in most existing data files in terms of recognized statistical evidence of accident causation. A systems approach is needed to identify critical, currently neglected variables and develop units of measurement and data collection procedures.

As on-highway, heavy-duty diesel engine designs have evolved to meet tighter emissions specifications and greater customer requirements, the crankcase environment for heavy-duty engine lubricants has changed. Engine lubricant quality is very important to help ensure engine durability, engine performance, and reduce maintenance downtime. Beginning in the late 1980's, a new Mack genuine oil specification and a new American Petroleum Institute (API) heavy-duty engine lubricant category have been introduced with each new U.S. heavy-duty, on-highway emissions specification. This paper documents the history and development of the Mack T-7, T-8, T-8A, T-8E, T-9, T-10, T-11, and T-12 engine lubricant tests.

The US EPA emission standards for 2010 on-highway and 2014 non-road diesel engines are extremely stringent, both in terms of oxides of nitrogen (NOX) and particulate matter (PM). Diesel engines typically operate lean and use at least 40-50 percent more air than what is needed for stoichiometric combustion of the fuel. As a result, significant excess oxygen (O₂) is present in diesel exhaust gas which prevents the application of the mature three-way catalyst (TWC) technology for NOX control used in gasoline engines. The objective of this work was to investigate whether or not the catalyzed DPF had a TWC-type of effect on NOX emissions and if so, why and to what extent when used on a diesel engine operating at reduced A/F ratio conditions.

Diesel particulate filters (DPF), known as traps in the mid-to late 1970s, were being developed for on-highway diesel applications. However, advanced engine design and in-cylinder engineering enabled diesel engines and vehicles to meet extremely low emission limits, including those of particulate matter (PM) without the need for DPF's or other auxiliary emission control devices. Late in 2000, the US EPA finalized its on-highway heavy-duty diesel emission standards, thus ending speculations regarding its stringency and establishing the lowest limits ever. The new nitric oxides (NOX) and PM limits are seen as technology-forcing. For NOX emissions, the debate rages on among the technical community about the merits of NOX adsorbers and urea selective catalytic reduction. On the other hand, there seems to be little doubt about DPF's as the technical solution for PM.

The post-1998 diesel engine emissions challenge was put forth in July 1995 by the Statement of Principles (SOP) signed by the manufacturers of heavy duty engines, the U.S. Environmental Protection Agency (EPA) and the California Air Resources Board (CARB). Through this SOP, the signatories agreed to reduce the on-highway diesel engine NOx emissions by 50% from the legislated 1998 4.0 g/bhp.hr to 2.0 g/bhp.hr by the year 2004 with no increase over the 1998 particulate matter legislated level set at 0.1 g/bhp.hr. There are provisions in the SOP for the optional grouping of the gaseous hydrocarbons and NOx, limiting them at a combined value of 2.5 g/bhp.hr with a 0.5 g/bhp.hr hydrocarbon limit. In North America, particulate matter emissions standards were first imposed on heavy duty diesel engines in 1988. Since then, the NOx and particulate matter were balanced by taking advantage of the trade-off between the two pollutants inherent in diesel engines.

As the design of engines advances and continues to push the capabilities of current hardware closer to their durability limits, more accurate and reliable analysis is necessary to ensure that designs are robust. This research evaluates a method of conjugate heat transfer analysis for a diesel engine that combines the combustion CFD, Engine FEA, and cooling jacket CFD with the aim of getting more accurate heat loss predictions and a more accurate temperature distribution in the engine than with current analysis methods. A 15.0 L Cummins ISX heavy duty engine operating at 1250 RPM and 15 bar BMEP load is selected for this work. Spray combustion computational fluid dynamics (CFD) simulations are performed for the diesel engine and the results are validated with experimental data. Finite Element Analysis (FEA) simulations were performed in a separate software platform.

Low intake manifold temperature, well below ambient, has many applications in internal combustion engines. In diesel engines, it can reduce NOx to a level of 2.0 g/hp-hr or below, going beyond the 1994 heavy duty diesel engine emissions standards. In gasoline engines, it can allow high compression ratio, turbocharged operation without end gas knock. This will permit ready conversion of some heavy duty diesel engines to gasoline operation at increased power density and lower emissions. In natural gas engines, it will allow base diesel engine to be converted to stoichiometric natural gas operation without increasing thermal loads. A three way catalyst can then be used to reduce emissions.

Usage of CVTs in automotive applications has begun to increase, however because of their relative newness and previous usage in nonautomotive applications, a broad base of technical information on the various types of CVT's does not exist. Most importantly though, no comparison information exists on the different types of configurations. Currently, there are a number of CVT technologies that have been used in automotive, off-road and industrial applications. This paper will highlight the characteristics, design limitations and efficiencies of the following basic CVT types:

An investigation was performed to determine the effects of applying on-highway heavy-duty diesel engine emissions reduction technology to an off-highway version of the engine. Special attention was paid to the typical constraints of fuel consumption, heat rejection, packaging and cost-effectiveness. The primary focus of the effort was NOx, reduction while hopefully not worsening other gaseous and particulate emissions. Hardware changes were limited to “bolt-on” items, thus excluding piston and combustion chamber modifications. In the final configuration, NOx was improved by 28 percent, particulates by 58 percent, CO and HC were also better and the fuel economy penalty was limited to under 4 percent. Observations are made about the effectiveness of various individual and combined strategies, and potential problems are identified.

This paper describes a distributed digital process control computer designed for large industrial processing plants that has been applied successfully to laboratory engine testing. Over the past two years several complete systems have been installed and adapted to control engines from 75 kW to over 1800 kW with various dynamometer/generator absorption devices. Control problems encountered, and solutions we have found, are discussed along with the wide range of capabilities this type of system can provide. A short comparison is made between distributed digital control systems and mini-computers, listing advantages and disadvantages of both.

The U.S. Army has long identified the need for rapid, reliable methods for analysis of fuels and lubricants on or near the battlefield. The analysis of fuels and lubricants under battlefield or near-battlefield conditions requires that the equipment be small, portable, rugged, quick, and easy to use. Over the past 15 to 20 years, several test kits and portable laboratories have been developed in response to this need. One instrumental technique that has been identified as a likely candidate to meet this need is near-infrared spectroscopy (NIR). To evaluate NIR as a candidate, a set of 280 fuel samples was used. This sample set contained samples of diesel fuel grades 1 and 2, Jet A-l, JP-5, and JP-8. Inspection data were collected on all the fuels as sample size permitted. Each sample was then scanned using a near-infrared spectrometer. Data analysis, model building, and calibration were conducted using a software package supplied with the instrument.

Since the turn of the millennium, automated vehicle technology has matured at an exponential rate, evolving from research largely funded and motivated by military and agricultural needs to a near-production market focused on everyday driving on public roads. Research and development has been conducted by a variety of entities ranging from universities to automotive manufacturers to technology firms demonstrating capabilities in both highway and urban environments. While this technology continues to show promise, corner cases, or situations outside the average driving environment, have emerged highlighting scenarios that impede the realization of full automation anywhere, anytime. This paper will review several of these corner cases and research deficiencies that need to be addressed for automated driving systems to be broadly deployed and trusted.

The 2010 emission standards for heavy-duty diesel engines in the U.S. have established a limit for oxides of nitrogen (NOx) emissions of 0.20 g/bhp-hr., a 90% reduction from the previous emission standards. However, it has been projected that even when the entire on-road fleet of heavy-duty vehicles operating in California is compliant with the 2010 emission standards, the upcoming National Ambient Air Quality Standards (NAAQS) requirement for ambient particulate matter and ozone will not be achieved in California without further significant reductions in NOx emissions from the heavy-duty vehicle fleet. Given this, there is potential of further reduction in NOx emissions limit standards for heavy duty engines in the US. Recently there have been extensive studies and publications focusing on ultra-low NOx after treatment technologies that help achieve up to 0.02g/bhp-hr. at tailpipe [1].

The primary objective of this study was to compare the performance of “new” plastic fuel tanks vs. “aged” plastic fuel tanks when subjected to the standard fire exposure test described in ECE R34.01, Annex 5 Section 5.0 “Resistance to Fire.” The program also included a comparison of failure modes of plastic vs. metal fuel tanks when subjected to a simulated post-crash pool fire. The “new” tanks were purchased from the OEM suppliers (not weathered or pre-conditioned with fuel). The “aged” tanks were obtained from vehicles that were operated in a warm climate and considered to be weathered and fully conditioned with fuel. Three vehicle types, representing three fuel tank shapes and installations, were evaluated: 1.) “thin profile” tank, typical of front wheel drive cars with the tank mounted on the underbody near the rear seat area and in front of the rear axle; 2.) “square profile” tank, typical of SUV's with the tank mounted behind the rear axle; and 3.)

This study compared diesel exhaust emission from four different diesel fuels: a conventional low sulfur D2 diesel (0.03% sulfur, 28% aromatics), California Air Resources Board (CARB) diesel (0.015% sulfur, 8% aromatics), “Swedish” diesel (<0.001% sulfur, 4% aromatics), and a Fischer-Tropsch (F-T) diesel (<0.0001% sulfur, <0.1% aromatics) fuel. The comparison included regulated emissions, hydrocarbon speciation, air toxics, aldehydes and ketones, particle size distribution, and greenhouse gas emissions. Testing was conducted using a Cummins B-Series engine installed both in a heavy light-duty truck operating on a chassis dynamometer and on an engine dynamometer. The chassis driving cycles included city, highway, and aggressive driving operation. Engine dynamometer tests included the U.S. transient cycle.

In the United States, most school buses are powered by diesel engines. Some have advocated replacing diesel school buses with natural gas school buses, but little research has been conducted to understand the emissions from school bus engines. This work provides a detailed characterization of exhaust emissions from school buses using a diesel engine meeting 1998 emission standards, a low emitting diesel engine with an advanced engine calibration and a catalyzed particulate filter, and a natural gas engine without catalyst. All three bus configurations were tested over the same cycle, test weight, and road load settings. Twenty-one of the 41 “toxic air contaminants” (TACs) listed by the California Air Resources Board (CARB) as being present in diesel exhaust were not found in the exhaust of any of the three bus configurations, even though special sampling provisions were utilized to detect low levels of TACs.

Two methods of sampling exhaust emissions are typically used for characterizing emissions from diesel engines: total dilution which uses a constant volume sampling (CVS) system and partial flow dilution which relies on proportionally diluting a small part from the main exhaust stream. The CVS dilutes the entire exhaust flow to a constant volumetric flowrate which allows for proportional sampling of the exhaust species during transient engine operation. For partial dilution sampling during transient engine operation, obtaining a proportional sample is more rigorous and dilution of the extracted sample must be continuously changed throughout the cycle in order for the extracted sample flowrate to be proportional to the continuously changing exhaust flow. Typically, regulated emissions measured using both methods for an engine platform have shown good correlation. The focus for this work was on the experimental investigation of the two methods for the measurement of unregulated species.

Exhaust emission data from several fuel effects studies were normalized and subjected to statistical analyses. The goal of this work was to determine whether emission effects of property variation in alternate-source fuels were similar, less pronounced, or more pronounced than the effects of property variation in petroleum fuels. A literature search was conducted, reviewing hundreds of studies and finally selecting nine which dealt with fuel property effects on emissions. From these studies, 15 test cases were reported. Due to the wide variety of vehicles, fuels, test cycles, and measurement techniques used in the studies, a method to relate them all in terms of general trends was developed. Statistics and methods used included bivariate correlation coefficients, regression analysis, scattergrams and goodness-of-fit determinations.

Overcharging lithium-ion batteries is a failure mode that is observed if the battery management system (BMS) or battery charger fails to stop the charging process as intended. Overcharging can easily lead to thermal runaway in a battery. In this paper, nickel manganese cobalt (NMC) battery modules from the Chevrolet Bolt, lithium manganese oxide (LMO) battery modules from the Chevrolet Volt, and lithium iron phosphate (LFP) battery modules from a hybrid transit bus were overcharged. The battery abuse and emissions tests were designed to intentionally drive the three different battery chemistries into thermal runaway while measuring battery temperatures, battery voltages, gaseous emissions, and feedback from volatile organic compound (VOC) sensors. Overcharging a battery can cause lithium plating and other exothermic reactions that will lead to thermal runaway.