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Reduced emissions, improved fuel economy, and improved performance are a priority for manufacturers of internal combustion engines. However, these three goals are normally interrelated and difficult to optimize simultaneously. Studying the experimental heat release provides a useful tool for combustion optimization. Heavy-duty diesel engines are inherently transient, even during steady state operation engine controls can vary due to exhaust gas recirculation (EGR) or aftertreatment requirements. This paper examines the heat release and the derived combustion characteristics during steady state and transient operation for a 1992 DDC series 60 engine and a 2004 Cummins ISM 370 engine. In-cylinder pressure was collected during repeat steady state SET and the heavy-duty transient FTP test cycles.

An Advanced Automotive Manikin (ADAM), is used to evaluate liquid cooling garments (LCG) for advanced space suits for extravehicular applications and launch and entry suits. The manikin is controlled by a finite-element physiological model of the human thermoregulatory system. ADAM's thermal response to a baseline LCG was measured.The local effectiveness of the LCG was determined. These new thermal comfort tools permit detailed, repeatable measurements and evaluation of LCGs. Results can extend to other personal protective clothing including HAZMAT suits, nuclear/biological/ chemical protective suits, fire protection suits, etc.

People who wear protective uniforms that inhibit evaporation of sweat can experience reduced productivity and even health risks when their bodies cannot cool themselves. This paper describes a new sweating manikin and a numerical model of the human thermoregulatory system that evaluates the thermal response of an individual to transient, non-uniform thermal environments. The physiological model of the human thermoregulatory system controls a thermal manikin, resulting in surface temperature distributions representative of the human body. For example, surface temperatures of the extremities are cooler than those of the torso and head. The manikin contains batteries, a water reservoir, and wireless communications and controls that enable it to operate as long as 2 hours without external connections. The manikin has 120 separately controlled heating and sweating zones that result in high resolution for surface temperature, heat flux, and sweating control.

The goal of this project was to demonstrate a low emissions, high efficiency heavy-duty on-highway natural gas engine. The emissions targets for this project are to demonstrate US 2010 emissions standards on the 13-mode steady state test. To meet this goal, a chemically correct combustion (stoichiometric) natural gas engine with exhaust gas recirculation (EGR) and a three way catalyst (TWC) was developed. In addition, a Sturman Industries, Inc. camless Hydraulic Valve Actuation (HVA) system was used to improve efficiency. A Volvo 11 liter diesel engine was converted to operate as a stoichiometric natural gas engine. Operating a natural gas engine with stoichiometric combustion allows for the effective use of a TWC, which can simultaneously oxidize hydrocarbons and carbon monoxide and reduce NOx. High conversion efficiencies are possible through proper control of air-fuel ratio.

A heavy-duty engine testing project involving Cummins Engine Company, Southwest Research Institute (SwRI), and West Virginia University (WVU) has been completed. This project evaluated the transient exhaust gas emissions rate of Cummins N-14 heavy-duty diesel engines converted to natural gas. Three heavy-duty N-14 diesel engines were converted to run on natural gas using a lean burn strategy by SwRI and are in field service in Santa Barbara Air Pollution Control District (SBAPCD). Two of the engines were tested under a steady-state cycle that simulates the U.S. heavy-duty transient cycle. The third engine was tested at the WVU Engine Research Laboratory following the U.S. Federal Test Procedure (FTP). However, at WVU, lean burn combustion strategy was shifted rich of stoichiometric during idling time of the FTP test. This may have caused the engine to produce more total hydrocarbons (THC) and carbon monoxide (CO).

The effects of fuel composition on emissions levels from compression ignition engines can be profound, and this understanding has led to mandated reductions in both sulfur and aromatic content of automotive diesel fuels. A Navistar T444E (V8, 7.3 liter) engine was installed on an engine dynamometer and subjected to transient emissions measurement using a variety of fuels, namely federal low sulfur pump diesel; California pump diesel; Malaysian Fischer-Tropsch fuel with very low sulfur and aromatic content; various blends of soy-derived biodiesel; a Fischer-Tropsch fuel with very low sulfur and 10% aromatics; and the same Fischer-Tropsch fuel with 10% isobutanol by volume. The biodiesel blends showed their ability to reduce particulate matter, but at the expense of increasing oxides of nitrogen (NOx), following the simple argument that cetane enhancement led to earlier ignition. However, the Fischer-Tropsch fuels showed their ability to reduce all of the regulated emissions.

Due to its high efficiency and superior durability the diesel engine is again becoming a prime candidate for future light-duty vehicle applications within the United States. While in Europe the overall diesel share exceeds 40%, the current diesel share in the U.S. is 1%. Despite the current situation and the very stringent Tier 2 emission standards, efforts are being made to introduce the diesel engine back into the U.S. market. In order to succeed, these vehicles have to comply with emissions standards over a 120,000 miles distance while maintaining their excellent fuel economy. The availability of technologies such as high-pressure common-rail fuel systems, low sulfur diesel fuel, NOx adsorber catalysts (NAC), and diesel particle filters (DPFs) allow the development of powertrain systems that have the potential to comply with the light-duty Tier 2 emission requirements. In support of this, the U.S.

Pollutants are a major issue of diesel engines, with oxides of nitrogen (NOx) and airborne total particulate matter (TPM) of primary concern. Current emission standards rely on laboratory testing using an engine dynamometer with a standard test procedure. Results are reported as an integrated value for emissions from a transient set of engine speed and load conditions over a length of time or a set of prescribed speed-load points. To be considered a valid test by the US EPA, the measured engine speed and load are compared to the prescribed engine speed and load and must be within prescribed regression limits.

Heavy-duty diesel engines (HDDE), because of their widespread use and reputation of expelling excessive soot, have frequently been held responsible for excessive amounts of overall environmental particulate matter (PM). PM is a considerable contributor to air pollution, and a subject of primary concern to health and regulatory agencies worldwide. The U.S. Environmental Protection Agency (EPA) has provided PM emissions regulations and standards of measurement techniques since the 1980's. PM standards set forth by the EPA for HDDEs are based only on total mass, instead of size and/or concentration. The European Union adopted a particle number emission limit, and it may influence the U.S. EPA to adopt particle number or size limits in the future. The purpose of this research was to study the effects biodiesel blended fuel and cetane improvers have on particle size and number.

As a part of the FutureTruck 2000 advanced technology student vehicle competition sponsored by the US Department of Energy and General Motors, West Virginia University has converted a full-size sport utility vehicle into a high fuel efficiency, low emissions vehicle. The environmental impact of the Chevrolet Suburban SUV, in terms of both greenhouse gas emissions and exhaust emissions, was reduced through hybridization without losing any of the functionality and utility of the base vehicle. The approach taken was one of using a high efficiency, state-of-the-art direct injection, turbocharged diesel engine coupled to a high output electric traction motor for power assist and to recover regenerative braking energy. The vehicle employs a state-of-the-art combination lean NOx catalyst, oxidation catalyst and particulate filter to ensure low exhaust emissions.

A key to the success of the national hydrogen and fuel cell codes and standards developments efforts to date was the creation and implementation of national templates through which the U.S. Department of Energy (DOE), the National Renewable Energy Laboratory (NREL), and the major standards development organizations (SDOs) and model code organizations coordinate the preparation of critical standards and codes for hydrogen and fuel cell technologies and applications and maintain a coordinated national agenda for hydrogen and fuel cell codes and standards

This paper summarizes the several of the studies in the Environmental Science Program being sponsored by DOE's Office of Heavy Vehicle Technologies (OHVT) through the National Renewable Energy Laboratory (NREL). The goal of the Environmental Science Program is to understand atmospheric impacts and potential health effects that may be caused by the use of petroleum-based fuels and alternative transportation fuels from mobile sources. The Program is regulatory-driven, and focuses on ozone, airborne particles, visibility and regional haze, air toxics, and health effects of air pollutants. Each project in the Program is designed to address policy-relevant objectives. Current projects in the Environmental Science Program have four areas of focus: improving technology for emissions measurements; vehicle emissions measurements; emission inventory development/improvement; ambient impacts, including health effects.

This paper summarizes current work in the Environmental Science & Health Effects (ES&HE) Program being sponsored by DOE's Office of Heavy Vehicle Technologies (OHVT) through the National Renewable Energy Laboratory (NREL). The program is regulatory-driven, and focuses on ozone, airborne particles, visibility and regional haze, air toxics, and health effects of air pollutants. The goal of the ES&HE Program is to understand atmospheric impacts and potential health effects that may be caused by the use of petroleum-based and alternative transportation fuels. Each project in the program is designed to address policy-relevant objectives. Studies in the ES&HE Program have four areas of focus: improving technology for emissions measurements; vehicle emissions measurements, emission inventory development/improvement; and ambient impacts, including health effects.

Pedestrians account for a significant ratio of traffic fatalities; as a result, research on methods of reducing vehicle-pedestrian crashes is of importance. In this paper, we describe a system architecture that allows the use of vehicle-to-pedestrian (V2P) communication as a means of generating situational awareness and eventually predicting hazards and warning drivers and pedestrians. In contrast, vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication for safety applications, V2P has not received much attention. One major reason for this lack of attention had been the unavailability of communication mechanisms between pedestrians and vehicles. Recent advances in enabling Wi-Fi and dedicated short range communication (DSRC) based communication using smart-phones is changing this picture. As a result, V2P communication can be considered as a possible solution.

As part of the 1998 Consent Decrees concerning alternative ignition strategies between the six settling heavy-duty diesel engine manufacturers and the United States government, the engine manufacturers agreed to perform in-use emissions measurements of their engines. As part of the Consent Decrees, pre- (Phase III, pre-2000 engines) and post- (Phase IV, 2001 to 2003 engines) Consent Decree engines used in over-the-road vehicles were tested to examine the emissions of oxides of nitrogen (NOx) and carbon dioxide (CO2). A summary of the emissions of NOx and CO2 and fuel consumption from the Phase III and Phase IV engines are presented for 30 second “Not-to-Exceed” (NTE) window brake-specific values. There were approximately 700 Phase III tests and 850 Phase IV tests evaluated in this study, incorporating over 170 different heavy duty diesel engines spanning 1994 to 2003 model years. Test vehicles were operated over city, suburban, and highway routes.

Growing concern over ground-level ozone and its role in smog formation has resulted in extensive investigation into identifying ozone sources. Motor vehicle exhaust, specifically oxides of nitrogen and hydrocarbons, have been identified as major ozone precursors in urban areas. Past research has concentrated on assessing the impact of emissions from gasoline fueled light duty vehicles. However, little work has been done on identifying ozone precursors from medium and heavy duty diesel fueled vehicles. This paper presents the results of testing performed on a Navistar T 444E 190 horsepower diesel engine which is certified as a light/heavy-duty emissions classification and is used in medium duty trucks up to 11,800 kg (26,000 lb) GVW. Regulated emissions and speciated hydrocarbon emissions were collected using a filter, bag and Tenax adsorption cartridges for both steady state and transient engine operation.

An electrochemical cell is presented which reduces NOx emissions from a vehicle fueled by dedicated natural gas. The cell is comprised of a honeycomb shaped ceramic which is chemically coated with an electrically conductive material in two distinct regions which serve as electrodes such that, with the application of a voltage potential, a cathode and anode are formed. As the exhaust gas flows through the inner channels of the cell, the electrochemical reduction of NOx at the cathode yields nitrogen gas and oxide ions. The nitrogen continues to flow through the cell while the oxide ions dissolve in the solid electrolyte. At the anodic zone, oxide ions are converted to oxygen gas. The pressure drop across the cell was experimentally measured to insure that the back pressure created by the cell does not create a significant reduction in the efficiency of the engine.

Reliable assessment of occupant thermal comfort can be difficult to obtain within automotive environments, especially under transient and asymmetric heating and cooling scenarios. Evaluation of HVAC system performance in terms of comfort commonly requires human subject testing, which may involve multiple repetitions, as well as multiple test subjects. Instrumentation (typically comprised of an array of temperature sensors) is usually only sparsely applied across the human body, significantly reducing the spatial resolution of available test data. Further, since comfort is highly subjective in nature, a single test protocol can yield a wide variation in results which can only be overcome by increasing the number of test replications and subjects. In light of these difficulties, various types of manikins are finding use in automotive testing scenarios.

We describe a study to identify potential biofuels that enable advanced spark ignition (SI) engine efficiency strategies to be pursued more aggressively. A list of potential biomass-derived blendstocks was developed. An online database of properties and characteristics of these bioblendstocks was created and populated. Fuel properties were determined by measurement, model prediction, or literature review. Screening criteria were developed to determine if a bioblendstock met the requirements for advanced SI engines. Criteria included melting point (or cloud point) < -10°C and boiling point (or T90) <165°C. Compounds insoluble or poorly soluble in hydrocarbon were eliminated from consideration, as were those known to cause corrosion (carboxylic acids or high acid number mixtures) and those with hazard classification as known or suspected carcinogens or reproductive toxins.

Mixing controlled compression ignition, i.e., diesel engines are efficient and are likely to continue to be the primary means for movement of goods for many years. Low-net-carbon biofuels have the potential to significantly reduce the carbon footprint of diesel combustion and could have advantageous properties for combustion, such as high cetane number and reduced engine-out particle and NOx emissions. We developed a list of over 400 potential biomass-derived diesel blendstocks and populated a database with the properties and characteristics of these materials. Fuel properties were determined by measurement, model prediction, or literature review. Screening criteria were developed to determine if a blendstock met the basic requirements for handling in the diesel distribution system and use as a blend with conventional diesel. Criteria included cetane number ≥40, flashpoint ≥52°C, and boiling point or T90 ≤338°C.