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This paper presents 3D finite element analysis performed for a composite cylindrical tank made of 6061-aluminum liner overwrapped with carbon fibers subjected to a burst internal pressure of 1610 bars. As the service pressure expected in these tanks is 700 bars, a factor of safety of 2.3 is kept the same for all designs. The optimal design configuration of such high pressure storage tanks includes an inner liner used as a gas permeation barrier, geometrically optimized domes, inlet/outlet valves with minimum stress concentrations, and directionally tailored exterior reinforcement for high strength and stiffness. Filament winding of pressure vessels made of fiber composite materials is the most efficient manufacturing method for such high pressure hydrogen storage tanks. The complexity of the filament winding process in the dome region is characterized by continually changing the fiber orientation angle and the local thickness of the wall.

Natural Gas engines are viewed as an alternative to diesel power in the quest to reduce heavy duty vehicle emissions in polluted urban areas. In particular, it is acknowledged that natural gas has the potential to reduce the inventory of particulate matter, and this has encouraged the use of natural gas engines in transit bus applications. Extensive data on natural gas and diesel bus emissions have been gathered using two Transportable Heavy Duty Vehicle Emissions Testing Laboratories, that employ chassis dynamometers to simulate bus inertia and road load. Most of the natural gas buses tested prior to 1997 were powered by Cummins L-10 engines, which were lean-burn and employed a mechanical mixer for fuel introduction. The Central Business District (CBD) cycle was used as the test schedule.

Currently, the chassis assembly contributes about 73 percent of the overall weight of a 14.63 m long haul trailer. This paper presents alternative design concepts for the structural floor of a van trailer utilizing sandwich panels with various material and geometric characteristics of the core layer in order to reduce its weight significantly below that of the current design configuration. The main objective of the new designs is to achieve optimal tradeoffs between the overall structural weight and the flexural stiffness of the floor. Various preliminary design concepts of the core designs were compared on the basis of a single section of the core structure. Six different designs were analyzed by weight, maximum displacement and maximum stress under bending and torsion loads. Each concept was kept uniform by length, thickness, loading and boundary conditions. Each design concept was examined through testing of scaled model for floor assemblies.

Recent advances in Metal Matrix Composites have made them ready for transition to large-volume production and commercialization. Such new materials seem to allow the fabrication of higher quality parts at less than 50 percent of the weight as compared to steel. The increasing requirements of weight savings and extended durability motivated the potential application of MMC technology into the heavy vehicle market. However, significant technical barriers such as joining are likely to hinder the broad applications of MMC materials in heavy vehicles. The focus of this paper is to examine the feasibility of manufacturing and the behavior of bolted joint connections made from aluminum matrix reinforced with Silicon Carbide (SiC) particles. Two reinforcement ratios: 20% and 45% were considered in this study. The first part of the paper concentrates on experimental evaluation of bolted MMC joints.

Selective Catalytic Reduction (SCR), using urea injection, is being examined as a method for substantial reduction of oxides of nitrogen (NOx) for diesel engines, but the urea injection rates must be controlled to match the NOx production which may need to be predicted during open loop control. Unfortunately NOx is usually measured in the laboratory using a full-scale dilution tunnel and chemiluminescent analyzer, which cause delay and diffusion (in time) of the true manifold NOx concentration. Similarly, delay and diffusion of measurements of all emissions cause the task of creating instantaneous emissions models for vehicle simulations more difficult. Data were obtained to relate injections of carbon dioxide (CO2) into a tunnel with analyzer measurements. The analyzer response was found to match a gamma distribution of the input pulse, so that the analyzer output could be modeled from the tunnel CO2 input.

Diesel engines are highly reliable, durable and are used for a wide range of applications with low fuel usage owing to its higher thermal efficiency compared to other mobile power sources. Heavy-duty diesel engines are used for both on-road and off-road applications and dominate the heavy-duty engine segment of the United States transportation market. Due to their high reliability, there are considerable numbers of on-road legacy heavy-duty diesel engine fleets still in use in the United States. These engines are relatively higher oxides of nitrogen (NOx) and particulate matter (PM) producers than post 2007 model year diesel engines. There have been various emission certification or verification programs which are carried out in states like California and Texas for different aftermarket retrofit devices, fuels and additive technologies for reducing NOx and PM emissions from these legacy diesel engines.

The need for a cleaner and less expensive alternative energy source to conventional petroleum fuels for powering the transportation sector has gained increasing attention during the past decade. Special attention has been directed towards natural gas (NG) which has proven to be a viable option due to its clean-burning properties, reduced cost and abundant availability, and therefore, lead to a steady increase in the worldwide vehicle population operated with NG. The heavy-duty vehicle sector has seen the introduction of natural gas first in larger, locally operated fleets, such as transit buses or refuse-haulers. However, with increasing expansion of the NG distribution network more drayage and long-haul fleets are beginning to adopt natural gas as a fuel.

The study was aimed at assessing in-use emissions of a USEPA 2010 emissions-compliant heavy-duty diesel vehicle powered by a model year (MY) 2011 engine using West Virginia University's Transportable Emissions Measurement System (TEMS). The TEMS houses full-scale CVS dilution tunnel and laboratory-grade emissions measurement systems, which are compliant with the Code of Federal Regulation (CFR), Title 40, Part 1065 [1] emissions measurement specifications. One of the specific objectives of the study, and the key topic of this paper, is the quantification of greenhouse gas (GHG) emissions (CO2, N2O and CH4) along with ammonia (NH3) and regulated emissions during real-world operation of a long-haul heavy-duty vehicle, equipped with a diesel particulate filter (DPF) and urea based selective catalytic reduction (SCR) aftertreatment system for PM and NOx reduction, respectively.

Exhaust gas composition and particulate matter emission levels were obtained from in-use heavy duty transit buses powered by 6V-92TA engines with different fuels. Vehicles discussed in this study were pulled out of revenue service for a day, in Phoenix, AZ, Pittsburgh, PA and New York, NY and tested on the Transportable Heavy Duty Vehicle Emissions Testing Laboratory employing a transient chassis dynamometer. All the vehicles, with engine model years ranging from 1982 to 1992, were operated on the Federal Transit Administration Central Business District Cycle. Significant reductions in particulate matter emissions were observed in the 1990-1992 model year vehicles equipped with the trap oxidizer systems. Testing vehicles under conditions that represent “real world” situations confirmed the fact brought to light that emission levels are highly dependent upon the maintenance and operating conditions of the engines.

The federal emission standards for heavy duty vehicle engines require the exhaust emissions to be measured and calculated in unit form as grams per break horse-power-hour (g/bhp-hr). Correct emission results not only depend on the precise emission measurement but also rely on the correct determination of vehicle energy consumption. A Transportable Heavy-Duty Vehicle Emission Testing Laboratory (THDVETL) designed and constructed at West Virginia University provides accurate vehicle emissions measurements in grams over a test cycle. This paper contributes a method for measuring the energy consumption (bhp-hr) over the test cycle by a chassis dynamometer. Comparisons of analytical and experimental results show that an acceptable agreement is reached and that the THDVETL provides accurate responses as the vehicle is operated under transient loads and speeds. This testing laboratory will have particular value in comparing the behavior of vehicles operating on alternative fuels.

The objective of this study was to evaluate iso-butanol (C4H9OH) as an alternative fuel for spark ignition engines. Unlike methanol (CH3OH) and ethanol (C2H5OH), iso-butanol has not been extensively studied in the past as either a fuel blend candidate with gasoline or straight fuel. The performance of a single cylinder engine (ASTM=CFR) was studied using alcohol-gasoline blends under different input parameters. The engine operating conditions were: three carburetor settings (three different fuel flow rates), spark timings of 5°, 10°, 15°, 20°, and 25° BTDC, and a range of compression ratios from a minimum of 7.5 to a maximum of 15 in steps of one depending on knock. The fuels tested were alcohol-gasoline blends having 5%, 10%, 15%, and 20% of iso-butanol, ethanol, and methanol. And also as a baseline fuel, pure gasoline (93 ON) was used. The engine was run at a constant speed of 800 RPM.

Gaseous and particulate emissions from heavy-duty vehicles are affected by fuel types, vehicle/engine parameters, driving characteristics, and environmental conditions. Transient chassis tests were conducted on twenty-six heavy-duty vehicles fueled with methanol, compressed natural gas (CNG), #1 diesel, and #2 diesel, using West Virginia University (WVU) Transportable Heavy-Duty Vehicle Emissions Testing Laboratory. The vehicles were operated on the central business district (CBD) testing cycle, and regulated emissions of carbon monoxide (CO), total hydrocarbon (HC), nitrogen oxides (NOx), and particulate matter (PM) were measured. Comparisons of regulated emissions results revealed that the vehicles powered on methanol and CNG produced much lower particulate emissions than the conventionally fueled vehicles.

The West Virginia University (WVU) Transportable Heavy-Duty Vehicle Emissions Testing Laboratory was employed to conduct chassis dynamometer tests in the field to measure the exhaust emissions from heavy-duty buses and trucks. This laboratory began operation in the field in January, 1992. During the period January, 1992 through June, 1993, over 150 city buses, trucks, and tractors operated by 18 different authorities in 11 states were tested by the facility. The tested vehicles were powered by 14 different types of engines fueled with natural gas (CNG or LNG), methanol, ethanol, liquified petroleum gas (LPG), #2 diesel, and low sulfur diesel (#1 diesel or Jet A). Some of the tested vehicles were equipped with exhaust after-treatment systems. In this paper, a total of 12 CNG-fueled and #2 diesel-fueled transit buses equipped with Cummins L-10 engines, were chosen for investigation.

A correlation study of vehicle exhaust emissions measurements was conducted by the West Virginia University (WVU) Transportable Heavy-Duty Vehicle Emissions Testing Laboratory and the Los Angeles County Metropolitan Transportation Authority (MTA) Emissions Testing Facility. A diesel fueled transit bus was tested by both chassis dynamometer emissions testing laboratories. Exhaust emissions were sampled from the tested vehicle during the operation of the Federal Transit Administration (FTA) Central Business District (CBD) testing cycle. Data of gaseous and particulate matter emissions was obtained at each testing laboratory. The emissions results were compared to evaluate the effects of different equipment, test procedures, and drivers on the measurements of exhaust emissions of heavy-duty vehicles operated on a chassis dynamometer.

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.

Regulated gaseous and particulate emissions were obtained from in-use vehicles, two trucks and two buses, operated on the Transportable Heavy Duty Engine Emissions Testing Laboratory. Presented here is the data on transient emissions from a refuse truck with a Cummins LTA10-260 engine, a GMC tractor with a CAT 3176 engine and two buses with Detroit Diesel 6V-92TA engines (one with a particulate trap and the other without) when tested on different fuels. The reported study on in-use heavy duty vehicles is part of an on-going program aimed at establishing a database on the exhaust emissions from vehicles tested on a chassis dynamometer under conditions that represent the ‘real-world’ situations. The paper also discusses, briefly, the entire testing laboratory. The Transportable Laboratory can be effectively used in testing programs, such as recall, deterioration and emission factors.

Recent interest in the effect of engine life on vehicle emissions, particularly those from alternately fueled engines, has led to a need to test heavy duty trucks in the field over their lifetime. West Virginia University has constructed two transportable laboratories capable of measuring emissions as a vehicle is driven through a transient test schedule. Although the central business district (CBD) cycle is well accepted for bus testing, no time-based schedule suited to the testing of class 8 trucks with unsynchronized transmissions is available. The Federal Test Procedure for certifying heavy duty engines can be translated with some difficulty into a flat road chassis cycle although original data clearly incorporated unpredictable braking and inclines. Two methods were attempted for this purpose, but only an energy conservation method proved practical.

The need to assess the effect of exhaust gas emissions from heavy duty vehicles (buses and trucks) on emission inventories is urgent. Exhaust gas emissions measured during the fuel economy measurement test procedures that are used in different countries sometimes do not represent the in-use vehicle emissions. Since both local and imported vehicles are running on the roads, it is thought that studying the testing cycles of the major vehicle manufacturer countries is worthy. Standard vehicle testing cycles on chassis dynamometer from the United States, Canada, European Community Market, and Japan1 are considered in this study. Each of the tested cycles is categorized as either actual or synthesized cycle and its representativness of the observed driving patterns is investigated. A total of fourteen parameters are chosen to characterize any given driving cycle and the cycles under investigation were compared using these parameters.

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.

Data has been gathered using the West Virginia University Heavy Duty Transportable Emissions Laboratories from buses operating on diesel and a variety of alternate fuels in the field. Typically, the transportable chassis dynamo meter is set up at a local transit agency and the selected buses are tested using the fuel in the vehicle at the time of the test. The dynamometer may be set up to operate indoors or outdoors depending on the space available at the site. Samples of the fuels being used at the site are collected and sent to the laboratory for analysis and this information is then sent together with emissions data to the Alternate Fuels Data Center at the National Renewable Energy Laboratory. Emissions data are acquired from buses using the Central Business District cycle reported in SAE Standard J1376; this cycle has 14 ramps with 20 mph (32.2 km/h) peaks, separated by idle periods.