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Emissions from light duty vehicles have traditionally been measured using a chassis dynamometer, while heavy duty testing has been based on engine dynamometers. However, the need for in-use vehicle emissions data has led to the development of two transportable heavy duty chassis dynamometers capable of testing buses and heavy trucks. A test cycle has been developed for Class 8 trucks, which typically have unsyncronized transmissions. This test cycle has five peaks, each consisting of an acceleration, cruise period, and deceleration, with speeds and acceleration requirements that can be met by virtually all vehicles in common service. Termed the “WVU 5 peak truck test”, this 8 km (5 mile) cycle has been used to evaluate the emissions from diesel and ethanol powered over-the-road tractors and from diesel and ethanol powered snow plows, all with Detroit Diesel 6V92 engines.

The use of a soy-based diesel fuel (biodiesel) has potential advantages over the use of a conventional petroleum diesel fuel including: Reduced dependence on foreign petroleum Lowering of greenhouse gas emissions Less air pollution and related public health risks in urban areas A life cycle study performed by the U.S. Department of Energy's National Renewable Energy Laboratory, the U.S. Department of Agriculture's Office of Energy and Ecobalance (completed in May 1998) helped to quantify the environmental benefits of the “cradle-to-grave” production and use of biodiesel. The study showed, for example, that substituting 100% biodiesel for petroleum diesel in urban buses reduced the life cycle emissions of carbon dioxide (CO2) by 78%. The study also pointed out some trade-offs of using biodiesel including increased life cycle hydrocarbon and NOx emissions.

A bi-fuel engine capable of operating either on compressed natural gas (CNG) or gasoline is being developed for the transition to alternative fuel usage. A Saturn 1.9 liter 4-cylinder engine was selected as a base powerplant. A control system that allows closed-loop optimization of both fuel delivery and spark timing was developed. Stock performance and emissions of the engine, as well as performance and emissions with the new controller on gasoline and CNG, have been documented. CNG operation in an engine designed for gasoline results in power loss because of the lower volumetric efficiency with gaseous fuel use, yet such an engine does not take advantage of the higher knock resistance of CNG. It is the goal of this research to use the knock resistance of CNG to recover the associated power loss. The two methods considered for this include turbocharging with a variable boost wastegate and raising the compression ratio while employing variable valve timing.

In order to obtain meaningful analyses of exhaust gas emissions and fuel economy for a heavy duty vehicle from a chassis dynamometer, the accurate simulation of road load characteristics is crucial. The adjusted amount of power to be absorbed by the chassis dynamometer during road driving of the tested vehicle needs to be calculated. In this paper, the performance of the chassis dynamometer under transient load cycle operations is discussed and the transient response of the power absorption system is presented. In addition, the design criteria of the chassis dynamometer used to test heavy duty vehicles under steady and transient load is described.

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 paper captures the recent events in relation with the Volkswagen (VW) Emissions Scandal and addresses the impact of this event on the future of power train development. The paper analyses the impact on the perspectives of the internal combustion engine, the battery based electric car and the hydrogen based technology. The operation of the United States Environmental Protection Agency (EPA), VW and the United States prosecutor, sparked by the action of the International Council on Clean Transportation (ICCT) is forcing the Original Equipment Manufacturers (OEM) towards everything but rationale immediate transition to the battery based electric mobility. This transition voids the value of any improvement of the internal combustion engine (ICE), especially in the lean burn, compression ignition (CI) technology, and of a better hybridization of powertrains, both options that have much better short term perspectives than the battery based electric car.

The bending fatigue performance of high temperature (1050 °C) vacuum carburized Nb modified 8620 steel, with niobium additions of 0.02, 0.06 and 0.1 wt pct, was evaluated utilizing a modified Brugger specimen geometry. Samples were heated at two different rates (20 and 114 °C min-1) to the carburizing temperature resulting in different prior austenite grain structures that depended on the specific Nb addition and heating rate employed. At the lower heating rate, uniform fine grained prior austenite grain structures developed in the 0.06 and 0.1 Nb steels while a duplex grain structure with the presence of large (>200 μm grains) developed in the 0.02 Nb steel. At the higher heating rate the propensity for abnormal grain growth was highest in the 0.02 Nb steel and complete suppression of abnormal grain growth was achieved only with the 0.1 Nb steel.

High strain rate sheet tensile tests (up to 300s-1) and Ohio State University (OSU) formability tests (up to an estimated strain rate of 10s-1) were performed to examine the effect of strain rate on the mechanical properties and formability of five ferritic stainless steels: HIGH PERFORMANCE-10™ 409 (HP-10 409), ULTRA FORM® 409 (UF 409), HIGH PERFORMANCE-10™ 439 (HP-10 439), two thicknesses of 18 Cr-Cb™ stainless steel, all supplied by AK Steel, and Duracorr®, a ferrite-tempered martensite dual-phase stainless steel supplied by Bethlehem Steel Corporation. Tensile results show that increasing strain rate resulted in increases in yield stress, flow stress, and stress at instability for all alloys tested. In addition, increases in uniform and total elongation were also found for each of the five alloys.

The effects of austenite grain size on the bending fatigue crack initiation and fatigue performance of gas carburized, modified 4320 steels were studied. The steels were identical in composition except for phosphorus concentration which ranged between 0.005 and 0.031 wt%. Following the carburizing cycle, specimens were subjected to single and triple reheat treatments of 820°C for 30 minutes to refine the austenite grain structure, and oil quenched and tempered at 150°C. Specimens subjected to bending fatigue were characterized by light metallography to determine microstructure and grain size, X-ray analysis for retained austenite and residual stress measurements, and scanning electron microscopy for examination of fatigue crack initiation and propagation. The surface austenite grain size ranged from 15 μm in the as-carburized condition to 6 and 4 μm diameter grain size for the single and triple reheat conditions, respectively.

Regulated emissions (THC, CO, NOx, and PM) and particulate SOF and sulfate fractions were determined for a 1995 Detroit Diesel Series 50 urban bus engine at varying fuel sulfur levels, with and without catalytic converters. When tested on EPA certification fuel without an oxidation catalyst this engine does not appear to meet the 1994 emissions standards for heavy duty trucks, when operating at high altitude. An ultra-low (5 ppm) sulfur diesel base stock with 23% aromatics and 42.4 cetane number was used to examine the effect of fuel sulfur. Sulfur was adjusted above the 5 ppm level to 50, 100, 200, 315 and 500 ppm using tert-butyl disulfide. Current EPA regulations limit the sulfur content to 500 ppm for on highway fuel. A low Pt diesel oxidation catalyst (DOC) was tested with all fuels and a high Pt diesel oxidation catalyst was tested with the 5 and 50 ppm sulfur fuels.

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.

An alternative fuel that has demonstrated considerable potential in reducing emissions and crude oil dependence is compressed natural gas (CNG). A dedicated CNG vehicle suffers from the lack of an adequate number of fueling stations and the poor range limited by CNG storage technology. A vehicle capable of operating on either gasoline or natural gas allows alternative fuel usage without sacrificing vehicle range and mobility. Although many such bi-fuel vehicles are in existence, historically they have employed older engine designs and made compromises in engine control parameters that can degrade performance relative to gasoline and increase emissions. A modern production engine, a 1992 Saturn 1.9 liter 16 valve powerplant, is being optimized for operation on each fuel to realize the full potential of CNG in a bi-fuel system. CNG operation in an engine designed for gasoline typically suffers from reduced power, due in part to displacement of air by gaseous fuel.

With the increased use of tubular steel products, especially for automotive hydroforming applications, there is increased interest in understanding the mechanical properties measured by tensile tests from specimens of different orientations in the tube. In this study, two orientations of tensile specimens were evaluated -- axial specimens with and without flattening and flattened circumferential specimens. Three steels were evaluated -- two thicknesses of aluminum killed drawing quality (AKDQ) steel and one thickness of high strength low alloy (HSLA) steel. Mechanical property data were obtained from the flat stock, conventional production tubes and quasi tubes. Quasi tubes were produced from the flat stock on a 3-roll bender, but the quasi tube was not welded or sized.

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.

This paper presents results from a study on speciation of the emission profiles and on the ozone forming potential of heavy-duty diesel exhaust under steady state engine operation. Very limited attempts have been made at determining the ozone forming potential of heavy duty diesel exhaust emissions. In this study a proportional sample of the dilute exhaust was drawn from a CFV-CVS system using a temperature controlled sampling line. The particulate matter was collected on a 70 mm Teflon coated glass fiber filter (TX40HI20WW), the semi-volatiles on XAD-2 copolymer resin and volatiles in Tedlar bags. The samples were analyzed by gas chromatography after conditioning and chemical extractions. The initial phase of the study was directed towards developing techniques and establishing protocols to determine the ozone forming potential of heavy-duty diesel exhaust. A pre-chamber naturally aspirated engine was tested on steady-state modes 1, 3, 5, 7 and 8 of the ISO 8 mode cycle.

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.

Techniques have been developed to sample and speciate dilute heavy duty diesel exhaust to determine the specific reactivities and the ozone forming potential. While the Auto/Oil Air Quality Improvement Research Program (AQIRP) has conducted a comprehensive investigation to develop data on potential improvements in vehicle emissions and air quality from reformulated gasoline and various other alternative fuels. However, the development of sampling protocols and speciation of heavy duty diesel exhaust is still in its infancy [1, 2, 3, 4, 5 and 6]. This paper focuses on the first phase of the heavy duty diesel speciation program, that involves the development of a unique set of sampling protocols for the gas phase, semi-volatile and particulate matter from the exhaust of engines operating on different types of diesel fuel. Effects of sampling trains, sampling temperatures, semi-volatile adsorbents and driving cycles are being investigated.

The influences of laboratory-induced hydrogen on the tensile deformation and fracture behavior of selected sheet steels including conventional DQSK and HSLA steels as well as newer DP and TRIP grades were evaluated. The effects of cold work, simulated paint baking, and natural aging were considered. Hydrogen effects were observable by increased flow stress, decreased ductility, altered neck geometry, and altered fracture mechanisms. Differences among the steels and conditions were observed and interpreted on the basis of microstructure, fracture behavior, and theories of hydrogen embrittlement.

Results of a research effort directed towards identifying and measuring the genotoxic properties of respirable particulate matter involved in mining exposures, especially those which may synergistically affect genotoxic hazard, are presented. Particulate matter emissions from a direct injection diesel engine have been sampled and assayed to determine the genotoxic potential as a function of engine operating conditions. Diesel exhaust from a Caterpillar 3304 diesel engine, representative of the ones found in underground mines, rated 100 hp at 2200 rpm is diluted in a multi-tube mini-dilution tunnel and the particulate matter is collected on 70 mm fluorocarbon coated glass fiber filters as well as on 8″ x 10″ hi-volume filters. A six mode steady state duty cycle was used to relate engine operating conditions to the genotoxic potential.

Most environments inhabited by living beings have dust. Much of that dust comes from the continuous flaking of our own skin and atmosphere borne particles of submicron size. Dust mites seem to play an important role in integrating fine scale dust, which they consume to grow, resulting in larger length scale dust. Dust continues to agglomerate and grow. Air filters are designed to remove dust and control dust agglomeration. We report a simple scaling law, based on kinematic simulations of dust filtration through a one dimensional idealized filter. The results reveal insights regarding how filters may clog in time. Our results may be of use to someone interested in designing customized air filters for optimum dust removal in an environment with a known dust distribution.