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Technical Paper

Development of a Desulfurization Strategy for a NOx Adsorber Catalyst System

2001-03-05
2001-01-0510
The aggressive reduction of future diesel engine NOx emission limits forces the heavy- and light-duty diesel engine manufacturers to develop means to comply with stringent legislation. As a result, different exhaust emission control technologies applicable to NOx have been the subject of many investigations. One of these systems is the NOx adsorber catalyst, which has shown high NOx conversion rates during previous investigations with acceptable fuel consumption penalties. In addition, the NOx adsorber catalyst does not require a secondary on-board reductant. However, the NOx adsorber catalyst also represents the most sulfur sensitive emissions control device currently under investigation for advanced NOx control. To remove the sulfur introduced into the system through the diesel fuel and stored on the catalyst sites during operation, specific regeneration strategies and boundary conditions were investigated and developed.
Technical Paper

Emission Reductions and Operational Experiences With Heavy Duty Diesel Fleet Vehicles Retrofitted with Continuously Regenerated Diesel Particulate Filters in Southern California

2001-03-05
2001-01-0512
Particulate emission control from diesel engines is one of the major concerns in the urban areas in California. Recently, regulations have been proposed for stringent PM emission requirements from both existing and new diesel engines. As a result, particulate emission control from urban diesel engines using advanced particulate filter technology is being evaluated at several locations in California. Although ceramic based particle filters are well known for high PM reductions, the lack of effective and durable regeneration system has limited their applications. The continuously regenerated diesel particulate filter (CRDPF) technology discussed in this presentation, solves this problem by catalytically oxidizing NO present in the diesel exhaust to NO2 which is utilized to continuously combust the engine soot under the typical diesel engine operating condition.
Technical Paper

Analytical Methodology for Design and Performance Assessment of Run-Off-Road Collision Avoidance Systems

1997-02-24
970455
Research in Intelligent Transportation Systems (ITS) has been increasingly focussed on the development of Collision Avoidance Systems (CAS). A CAS would reduce the incidence of collisions by providing warnings to the driver to take evasive action. Because single vehicle roadway departures, also known as Run-off-Road (ROR) events, are a cause of a significant portion of vehicle accidents and fatalities, an effective CAS for ROR can potentially improve highway safety dramatically. The development of performance specifications for CAS for ROR events is a part of an ongoing three-phase program for NHTSA (National Highway Traffic Safety Administration). This paper focusses on the development and application of a powerful simulation tool, RORSIM, for CAS assessments over a wide range of environmental, roadway, driver, vehicle and CAS operating conditions. The results of CAS effectiveness studies are presented.
Technical Paper

A Continuously Variable Power Split Transmission for Automotive Applications

1997-02-24
970687
Continuously variable transmissions, commonly known as CVT's, have been shown to be feasible alternatives to the conventional multi-step gear transmissions (standard or automatic) typically used in automotive applications. Most CVT applications, however, rely on a shaft-to-shaft transmission arrangement, in which the belt-sheave action limits the load capacity of the transmission, particularly at the high power ranges (low speed, high torque). In this paper, a system based on a combined planetary gear train and a continuously variable pulley system is presented. The uniqueness of this arrangement is that the variable pulleys provide a power/torque split and recirculation function, which, when combined with the planetary gear train function, produces a continuously variable power split transmission system.
Technical Paper

Automobile Body Panel Color Measurement Test

1997-02-24
970995
It has been proposed that an automated remote color inspection of automobile body panels is possible with a reasonably precise color measurement. This paper outlines a test of a new 3D color measurement technology as applied to this task and presents the results of the first test. A camera is set up several feet away from a car body; a 3D orientation measuring system takes both 3D and color data from the car. The raw data is presented as a set of 3D graphs; the geometry-corrected data is also provided. Statistical analysis is presented to indicate system precision.
Technical Paper

Modeling and Analysis of Microstructure Development in Resistance Spot Welds of High Strength Steels

1998-09-29
982278
In this study, an incrementally coupled finite element analysis procedure is used to analyze the electrical, thermal, and mechanical interaction during resistance spot welding processes. The results of the finite element analysis are validated by experimental measurements of the weld nugget sizes and dynamic resistance. The temperature results from the thermo-electric analysis are used as the input for the prediction of the microstructure evolution in the resistance spot welds of high strength steels. Consequently such welding parameters as welding current, electrode force, electrode designs, cooling water temperature and flow rate, and electrode holding time can be linked with the weld nugget size, microstructure and mechanical properties in spot welds, and eventually the residual stresses and performance of spot welded structures.
Technical Paper

Fleet Test Using Butane and Propane Mixtures

1998-10-19
982444
This paper describes the results of a liquefied petroleum gas (LPG) fleet test conducted using para-transit, medium-duty vehicles. The vehicles were part of an active municipal fleet providing daily service on varying operating routes. Over a period of nine months, each vehicle was fueled with a series of butane/propane mixtures. The mixtures tested were HD5 LPG as the baseline fuel, 20 percent butane/80 percent propane, 30 percent butane/70 percent propane, and a final blend of 50 percent butane/50 percent propane by volume. The test vehicles showed improved fuel economy as the butane content increased in the fuel mixture, even without modification to existing LPG fuel systems. The improved fuel performance was consistent with the higher energy content of butane, compared to an equal volume of propane. The vehicles displayed no symptoms of performance or maintenance problems that would be related to operation of the fuel mixtures.
Technical Paper

Characterization of Nugget Development under Electrode Wear Conditions in Resistance Spot Welding

1998-09-29
982363
The effects of electrode wear on nugget development during resistance spot welding are major concerns in auto-body assembly and manufacturing. By considering detailed electrode-sheet interactions using advanced finite element modeling procedure, this paper presents a framework for detecting the electrode wear conditions and associated nugget development characteristics. Two important in-process parameters are studied in detail. They are the electrode movement and the dynamic resistance. It is found that the second-order derivative of the electrode movement and the first-order derivative of the dynamic resistance can be correlated in a fundamental form to identify the detailed nugget development process under various electrode wear conditions.
Technical Paper

A Double Planetary Gear Train-CVT Transmission with Multiple Applications

1995-02-01
950094
A family of transmission systems based on a “Planetary Gear - CVT” mechanism is presented here. The systems considered consist of two compound planetary gear trains connected through a CVT pulley system to provide the power/torque split and recirculation function, without the use of additional clutches and/or chain drives. A two degree of freedom system results in which one of the degrees of freedom is directly related to the CVT ratio. The mechanisms considered here combine the gear reduction function of compound planetary gear trains with the continuously variable trans- used as a circulating power control unit. The kinematics and dynamics of this family of systems is presented with emphasis on the belt forces, torques on the various shafts and the overall input/output velocity ratios through the CVT ratio span. Then a parametric analysis is conducted to characterize the effect of the various functional ratios and parameters of the system in terms of the overall performance.
Technical Paper

Use of the West Virginia University Truck Test Cycle to Evaluate Emissions from Class 8 Trucks

1995-02-01
951016
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.
Technical Paper

The Design of a Bi-Fuel Engine Which Avoids the Penalties Associated with Natural Gas Operation

1995-02-01
950679
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.
Technical Paper

Transient Emissions Tests of Cummins N-14 Natural Gas Engine

1995-11-01
952653
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).
Technical Paper

Speciation of Hydrocarbon Emissions from a Medium Duty Diesel Engine

1996-02-01
960322
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.
Technical Paper

Dynamic Vehicle Simulation to Evaluate Countermeasure Systems for Run-Off-Road Crashes

1996-02-01
960517
An important part of ITS (Intelligent Transportation Systems, formerly IVHS) is the development of collision avoidance systems. These systems continuously sense the dynamic state of the vehicle and the roadway situation, and they assess the potential for a collision. When the system determines that an emergency situation might be developing, it warns the driver to take evasive action. Such countermeasure systems must be subjected to rigorous testing to ensure reasonable performance in all foreseeable circumstances and effectiveness in reducing the incidence of collisions. The efficiency and safety of testing can be greatly enhanced by using a dynamic simulation of a vehicle in near-collision situations and “equipping” the vehicle with a proposed collision avoidance system. This paper discusses the development and application of a time-domain simulation code based on a dynamic model of the driver/vehicle/counter-measure system.
Technical Paper

Investigation of a Radio Frequency Plasma Ignitor for Possible Internal Combustion Engine Use

1997-02-24
970071
This paper outlines the development process of a radio frequency (RF) plasma ignitor and its application to internal combustion engines. The system features a high Q quarter-wave coaxial cavity resonator that serves as an electric field magnifier and as a discharge device. The preliminary characteristics of the cavity have been studied by the construction and operation of larger scaled devices. Testing has been performed using these devices in a testing apparatus operating under ambient conditions. Once an analysis of the large-scale device is complete, a smaller device, more inclined to interfacing with a standard engine, will be constructed and tested on a full scale engine. The final device is intended to operate in the 800-1500 MHz range.
Technical Paper

Zero Dimensional Combustion Modeling of an Axial Vane Rotary Engine

1997-02-24
970069
A zero dimensional combustion model of an axial vane rotary engine has been developed. The engine is a positive displacement mechanism that permits the four “stroke” action to occur in one revolution of the shaft with a minimum number of moving components. Current modeling efforts for this engine require improved estimations of engine parameters such as chamber pressure, chamber wall temperature, gas temperature, and heat loss. The purpose of this investigation was to develop a zero dimensional combustion model that predicts the above-mentioned parameters in a quick and accurate manner for a spark ignition or compression ignition version of the engine. For this effort, NASA's ZMOTTO code was modified. Piston engine data and the results from the modified ZMOTTO code are in good agreement.
Technical Paper

Comparative Emissions from Natural Gas and Diesel Buses

1995-12-01
952746
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.
Technical Paper

Ideal Computer Analysis of a Novel Engine Concept

1996-02-01
960080
A novel engine concept, currently under study, addresses many of the problems commonly associated with conventional internal combustion engines. In its simplest form the novel engine consists of a single crankshaft operating both a piston compressor and a piston expander which are connected by a continuous flame combustion chamber. One might regard this as a Brayton piston engine which is similar to a previous engine investigated by Warren. Also, due to the use of piston cylinders as the compression and expansion devices, this engine varies little mechanically from current engine technology thus allowing for easy implementation. The main improvement from conventional engine design is that the expansion cylinder can have a larger displacement than that of the compression cylinder. This allows more power to be extracted by lowering the loss due to blowdown and this will increase the thermal efficiency.
Technical Paper

An Approach to Simulate Chassis Dynamometer Test Cycles with Engine Dynamometer Test Cycles for Heavy-Duty Urban Buses

1996-10-01
962196
A mathematical model has been developed to transfer Chassis Dynamometer (CD) test cycles for heavy duty vehicles to the equivalent Engine Dynamometer (ED) test cycles. The model assumed a generalized drivetrain layout, and a variable drive line efficiency. An interactive computer code was written to represent the mathematical model for different drivetrain systems. Several CD test cycles were used to obtain equivalent ED test cycles for a sample based upon an urban bus equipped with an automatic transmission. Results showed the possibility of simulating CD test cycles with equivalent ED test cycles for heavy-duty urban buses under certain assumptions.
Technical Paper

Speciation of Heavy Duty Diesel Exhaust Emissions under Steady State Operating Conditions

1996-10-01
962159
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.
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