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Octane appetite of modern engines has changed as engine designs have evolved to meet performance, emissions, fuel economy and other demands. The octane appetite of seven modern vehicles was studied in accordance with the octane index equation OI=RON-KS, where K is an operating condition specific constant and S is the fuel sensitivity (RONMON). Engines with a displacement of 2.0L and below and different combinations of boosting, fuel injection, and compression ratios were tested using a decorrelated RONMON matrix of eight fuels. Power and acceleration performance were used to determine the K values for corresponding operating points. Previous studies have shown that vehicles manufactured up to 20 years ago mostly exhibited negative K values and the fuels with higher RON and higher sensitivity tended to perform better.

A project was conducted by Southwest Research Institute on behalf of the California Air Resources Board and the South Coast Air Quality Management District to demonstrate the technical feasibility of utilizing closed-loop three-way catalyst technology in off-road equipment applications. Five representative engines were selected, and baseline emission-tested using both gasoline and LPG. Emission reduction systems, employing three-way catalyst technology with electronic fuel control, were designed and installed on two of the engines. The engines were then installed in a fork lift and a pump system, and limited durability testing was performed. Results showed that low emission levels, easily meeting CARB's newly adopted large spark-ignited engine emission standards, could be achieved.

A new approach to reclaiming the spoil areas produced by area-type mining operations has been developed. This system uses a machine known as a winch-dozer, consisting of a pair of large back-to-back buckets which are drawn by cable across spoil piles, moving back and forth between a “tailblock” anchor and a “drawworks” winch unit developed as an attachment to a large crawler tractor. The system is expected to reduce the cost of reclamation leveling by 40-50%. The system permits more effective power utilization due to the blade system's light weight, induces caving of spoil banks, and permits moving spoil in both directions of blade travel.

The Texas Department of Transportation (TxDOT) began using an emulsified diesel fuel in July 2002. They initiated a simultaneous study of the effectiveness of this fuel in comparison to 2D on-road diesel fuel, which they use in both their on-road and off-road equipment. The study also incorporated analyses for the fleet operated by the Associated General Contractors (AGC) in the Houston area. Some members of AGC use 2D off-road diesel fuel in their equipment. The study included comparisons of fuel economy and emissions for the emulsified fuel relative to the conventional diesel fuels. Cycles that are known to be representative of the typical operations for TxDOT and AGC equipment were required for use in this study. Four test cycles were developed from data logged on equipment during normal service: 1) the TxDOT Telescoping Boom Excavator Cycle, 2) the AGC Wheeled Loader Cycle, 3) the TxDOT Single-Axle Dump Truck Cycle, and 4) the TxDOT Tandem-Axle Dump Truck Cycle.

Tests were conducted on a variety of commercially available spark plugs to determine the influence of igniter design on initial kernel formation and overall performance. Flame kernel formation was investigated using high-speed schlieren visualization. The flame growth rate was quantified using the area of the burned gas region. The results showed that kernel growth rate was heavily influenced by electrode geometry and configuration. The igniters were also tested in a bomb calorimeter to determine the levels of supplied and delivered energy. The typical ratio of supplied to delivered energy was 20% and igniters with a higher internal resistance delivered more energy and had faster kernel formation rates. The exception was plugs with large amounts of conductive mass near the electrodes, which had very slow kernel formation rates despite relatively high delivered energy levels.

Swirl plane Particle Image Velocimetry (PIV) measurements were performed in a single-cylinder optically accessible gasoline direct injection (DISI) engine using a borescope introduced through the spark plug hole. This allowed the use of a contoured piston and the visualization of the flow field in and around the piston bowl. The manifold absolute pressure (MAP) was fixed at 90 kPa and the engine speed was varied in increments of 250 rpm from 750 rpm to 2000 rpm. Images were taken from 270° to 320° bTDC of compression at 10° intervals to study the evolution of the velocity fluctuations. Measurements were performed with and without fuel injection to study its effect on the in-cylinder flow fields. Fuel was injected at 10 MPa and 5 MPa. The 2-D spatial mean velocities of individual flow fields and their decompositions were averaged over 100 cycles and used to investigate the effects of engine speed and image timing on the flow field.

This paper discusses the techniques and diagnostic significance of atomic absorption, atomic emission, and infrared spectrometric analysis of crankcase lubricants, with the use of supplementary data where pertinent. The parameters affecting used oil analytical data are discussed in terms of examples from Army general purpose vehicle test engines. Wear metals in used gear oils are also discussed and examples are given. Analytical methods and their applications are fully described, and the equipment and procedures for infrared spectroscopy and gas chromatography techniques are outlined.

The process of developing, parameterizing, validating, and maintaining models occurs within a wide variety of tools, and requires significant time and resources. To maximize model utilization, models are often shared between various toolsets and experts. One common example is sharing aircraft engine models with airframers. The functionality of a given model may be utilized and shared with a secondary model, or multiple models may run collaboratively through co-simulation. There are many technical challenges associated with model sharing and co-simulation. For example, data communication between models and tools must be accurate and reliable, and the model usage must be well-documented and perspicuous for a user. This requires clear communication and understanding between computer scientists and engineers. Most often, models are developed by engineers, whereas the tools used to share the models are developed by computer scientists.

The engine intake process governs many aspects of the flow within the cylinder. The inlet valve is the minimum area, so gas velocities at the valve are the highest velocities seen. Geometric configuration of the inlet ports and valves, and the opening schedule create organized large scale motions in the cylinder known as swirl and tumble. Good charge motion within the cylinder will produce high turbulence levels at the end of the compression stroke. As the turbulence resulting from the conversion energy of the inlet jet decays fast, the strategy is to encapsulate some of the inlet jet in the organized motions. In this work the baseline port of a 2.0 L gasoline engine was modified by inserting a tumble plate. The work was done in support of an experimental study for which a new single-cylinder research engine was set up to allow combustion system parameters to be varied in steps over an extensive range. Tumble flow was one such parameter.

The design of helical Intake ports for swirl generation is a process that has been developed over a number of years through primarily empirical methods. A number of design rules have been established that enable designers to develop ports that approach the state-of-the-art for maximum swirl generation with minimum pressure loss. More recently, computer-aided design (CAD) tools have been introduced that permit geometry and features to be accurately defined by mathematical surface descriptions, and to be parameterized such that derived geometry is updated automatically along with parent features. The author has developed a parametric design approach for helical ports that incorporates the lessons learned from experience into a systematic design procedure. This procedure takes advantage of the current CAD capabilities to expedite the design process and improve the result.

SCR-on-filter, or SCRoF, is an emerging technology for different market segments and vehicle applications. The technology enables simultaneous particulate matter trapping and NOX reduction, and provides thermal management and aftertreatment packaging benefits. However, there is little information detailing the lubricant derived exposure effects on functional SCR performance. A study was conducted to evaluate the impact of various oil consumption pathways on a light duty DOC and SCRoF aftertreatment system. This aftertreatment system was aged utilizing an engine test bench modified to enable increased oil consumption rates via three unique oil consumption pathways. The components were characterized for functional SCR performance, ash morphology, and ash deposition characteristics. This included utilizing techniques, such as SEM / EDS, to evaluate the ash structures and quantify the ash elemental composition.

A higher octane quality fuel used in premium-recommended vehicles has the potential for delivering better acceleration and power. Octane number is a standard measure for the anti-knock quality of a gasoline fuel. A higher octane number fuel can withstand more compression before detonation (or knock). Higher compression ratios directly correlate with engine power and thermodynamic efficiency. Hence engines that are designed for higher octane or premium grade fuels should typically develop higher power by extracting more from the calorific value of the fuel. However, in the case of premium-recommended vehicle models that are designed to run even on lower octane fuels, the extent of performance benefits of using premium grade higher octane fuels can be deciphered via vehicle testing. In this regard, two gasoline fuels with anti-knock index values (AKI) of 87 and 91 respectively were compared in five premium-recommended vehicles for acceleration and power benefits.

Copper ion exchange procedures were used to prepare zeolite-based catalysts for NOx reduction in lean (oxygen-rich) exhaust. Energy dispersive x-ray fluorescence and scanning electron microscopy analyses confirmed the presence of copper in the zeolite matrix. Zeolites were applied onto honeycomb and foam substrates, and evaluated for catalytic NOx reduction efficiency using engine exhaust. Copper-exchanged zeolite catalysts prepared for this study revealed NOx reduction of 95 percent for a period of seven minutes using previously adsorbed exhaust hydrocarbons as the reducing agent. Experiments using ethylene injection to supplement the exhaust suggest long-term and sustained NOx reduction, initially observed at 52 percent. Experimental results and performance comparisons of ZSM-5, mordenite, and Y-type zeolites are discussed. Zeolite catalysts based on Cu-mordenite showed high levels of initial NOx reduction, while results using Cu-ZSM-5 suggested better long-term activity.

This paper describes a hybrid robust nonlinear control approach for modern diesel engines running low temperature combustion and conventional diesel combustion modes. Using alternative combustion modes has become a promising approach to reduce engine emissions. However, due to very different in-cylinder conditions and fueling parameters for different combustion modes, control of engines operating multiple combustion modes is very challenging. It becomes difficult for conventional calibration / mapping based approaches to produce satisfactory results in terms of engine torque responses and emissions. Advanced control techniques are then demanded to accomplish the tasks. An innovative hybrid control system is designed to track different key engine operating variables at different combustion modes as well as avoid singularity which is inherent for turbocharged diesel engines running multiple combustion modes.

Fossil fuel consumption is a significant factor in terms of both economic and environ-mental impact of on- and off-highway systems. Because fuel consumption can be directly tied to equipment efficiency, gains in efficiency can lead to reduction in operating costs as well as conservation of nonrenewable resources. Fluid performance has a direct effect on the efficiency of a hydraulic system. A procedure has been developed for measuring a fluid's effect on the degree to which mechanical power is efficiently converted to hydraulic power in pumps typical of off-highway applications.

Fuel conservationists will welcome this practicable proposal for converting railroads from diesel fuel to propane gas propulsion. Propane is no newcomer to the fuel family, but the advantages of economy, simplicity of operation, minimal maintenance, and extended life of equipment, as presented in this paper, show up its unexploited and extensive potential use in all mobile units. This careful study includes experimental results and data especially applied to railroad engines, even to conversion plans for existing engines that allows an interchangeable fuel system to accommodate present supply and variable cost factors in the United States.

The effects of downspeeding and supercharging a passenger car diesel engine were studied through laboratory investigation and vehicle simulation. Changes in the engine operating range, transmission gearing, and shift schedule resulted in improved fuel consumption relative to the baseline turbocharged vehicle while maintaining performance and drivability metrics. A shift schedule optimization technique resulted in fuel economy gains of up to 12% along with a corresponding reduction in transmission shift frequency of up to 55% relative to the baseline turbocharged configuration. First gear acceleration, top gear passing, and 0-60 mph acceleration of the baseline turbocharged vehicle were retained for the downsped supercharged configuration.

This project’s objective was to generate experimental data to evaluate the impact of metals doped B20 on diesel particle filter (DPF) ash loading and performance compared to that of conventional petrodiesel. The effect of metals doped B20 vs. conventional diesel on a DPF was quantified in a laboratory controlled accelerated ash loading study. The ash loading was conducted on two DPFs – one using ULSD fuel and the other on B20 containing metals dopants equivalent to 4 ppm B100 total metals. Engine oil consumption and B20 metals levels were accelerated by a factor of 5, with DPFs loaded to 30 g/L of ash. Details of the ash loading experiment and on-engine DPF performance evaluations are presented in the companion paper (Part I). The DPFs were cleaned, and ash samples were taken from the cleaned material. X-ray Fluorescence (XRF), X-Ray Photoelectron Spectroscopy (XPS) and X-Ray Diffraction (XRD) were conducted on the ash samples.

The United States and Europe are mandating increasingly severe diesel fuel specifications, particularly with respect to sulfur content, and in some areas, aromatics content. This trend is directed towards reducing vehicle exhaust emissions and is generally beneficial to fuel quality, ignition ratings, and stability. However, laboratory studies, as well as recent field experience in Sweden and the United States, indicate a possible reduction in the ability of fuels to lubricate sliding components within the fuel injection system. These factors, combined with the trend toward increasing injection pressure in modern engine design, are likely to result in reduced durability and failure of the equipment to meet long-term emissions compliance. The U.S. Army Belvoir Fuels and Lubricants Research Facility (BFLRF) located at Southwest Research Institute (SwRI) developed an accelerated wear test that predicts the effects of fuel lubricity on injection system durability.

An experimental sensor array that measures dynamic exhaust temperature and dynamic smoke for the purpose of diagnosing diesel engine fuel injection equipment was designed, built, and tested. The sensor array is portable and easily installed on truck tailpipes, and was tested using two 6V-53 Detroit Diesel engines. The dynamic temperature sensor is a very high response instrument capable of measuring changes in gas temperature in excess of 104°F/second. The dynamic smokemeter is an optical device designed to measure very low levels of light opacity in the smoke plume, with a response compatible with the engine firing frequency. Dynamic exhaust temperature data had more diagnostic significance than dynamic smoke in the detection of maximum power degrading fuel injection faults.