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It is projected that even when the entire on-road fleet of heavy-duty vehicles operating in California is compliant with 2010 emission standards of 0.20 g/bhp-hr, the National Ambient Air Quality Standards (NAAQS) requirements for ambient ozone will not be met. It is expected that further reductions in NOX emissions from the heavy-duty fleet will be required to achieve compliance with the ambient ozone requirement. To study the feasibility of further reductions, the California Air Resources Board (CARB) funded a research program to demonstrate the potential to reach 0.02 g/bhp-hr NOX emissions. This paper details the work executed to achieve this goal on the heavy-duty Federal Test Procedure (FTP) with a heavy-duty natural gas engine equipped with a three-way catalyst. A Cummins ISX-12G natural gas engine was modified and coupled with an advanced catalyst system.

The 2010 emissions standards for heavy-duty engines have established a limit of oxides of nitrogen (NOX) emissions of 0.20 g/bhp-hr. However, the California Air Resource Board (ARB) projects that even when the entire on-road fleet of heavy-duty vehicles operating in California is compliant with 2010 emission standards, the National Ambient Air Quality Standards (NAAQS) requirement for ambient particulate matter (PM) and Ozone will not be achieved without further reduction in NOX emissions. The California Air Resources Board (CARB) funded a research program to explore the feasibility of achieving 0.02 g/bhp-hr NOX emissions.

Recent 2010 emissions standards for heavy-duty engines have established a limit of oxides of nitrogen (NOX) emissions of 0.20 g/bhp-hr. However, CARB has projected that even when the entire on-road fleet of heavy-duty vehicles operating in California is compliant with 2010 emission standards, the National Ambient Air Quality Standards (NAAQS) requirement for ambient particulate matter and Ozone will not be achieved without further reduction in NOX emissions. The California Air Resources Board (ARB) funded a research program to explore the feasibility of achieving 0.02 g/bhp-hr NOX emissions. This paper details engine and aftertreatment NOX management requirements and model based control considerations for achieving Ultra-Low NOX (ULN) levels with a heavy-duty diesel engine. Data are presented for several Advanced Technology aftertreatment solutions and the integration of these solutions with the engine calibration.

The most recent 2010 emissions standards for heavy-duty engines have established a tailpipe limit of oxides of nitrogen (NOX) emissions of 0.20 g/bhp-hr. However, it is projected that even when the entire on-road fleet of heavy-duty vehicles operating in California is compliant with 2010 emission standards, the National Ambient Air Quality Standards (NAAQS) requirement for ambient particulate matter and Ozone will not be achieved without further reduction in NOX emissions. The California Air Resources Board (CARB) funded a research program to explore the feasibility of achieving 0.02 g/bhp-hr NOX emissions.

The U.S. Army has long identified the need for rapid, reliable methods for analysis of fuels and lubricants on or near the battlefield. The analysis of fuels and lubricants under battlefield or near-battlefield conditions requires that the equipment be small, portable, rugged, quick, and easy to use. Over the past 15 to 20 years, several test kits and portable laboratories have been developed in response to this need. One instrumental technique that has been identified as a likely candidate to meet this need is near-infrared spectroscopy (NIR). To evaluate NIR as a candidate, a set of 280 fuel samples was used. This sample set contained samples of diesel fuel grades 1 and 2, Jet A-l, JP-5, and JP-8. Inspection data were collected on all the fuels as sample size permitted. Each sample was then scanned using a near-infrared spectrometer. Data analysis, model building, and calibration were conducted using a software package supplied with the instrument.

Automotive catalytic converters must provide a very high level of mechanical and thermal durability to maintain performance during their 100,000 to 150,000 mile life expectancy. The work reported herein characterizes the converter as a base (can) excited spring (mat material) supported mass (substrate). A mat material coupon test apparatus was developed for the purpose of providing parameter data for the converter model in the form of stiffness and material loss factor data as a function of shear deflection across the mat. An intumescent mat material was chosen and its dynamic properties evaluated for a range of converter operating parameters. The mat material response properties were placed into a mat material database as a function of gap bulk density, substrate temperature, and temperature gradient across the mat.

To aid in the catalytic converter design and development process, a test apparatus was designed and built which will allow comparative evaluation of the durability of candidate mat materials under highly controlled thermal and vibration environments. The apparatus directly controls relative shear deflection between the substrate and can to impose known levels of mat material strain while recording the transmitted shear force across the mat material. Substrate and can temperatures are controlled at constant levels using a resistive thermal exposure (RTE) technique. Mat material fatigue after several million cycles is evident by a substantial decrease in the transmitted force. A fragility test was found to be an excellent method to quickly compare candidate materials to be used for a specific application. Examples of test results from several materials are given to show the utility of the mat material evaluation technique.

The 2010 emission standards for heavy-duty diesel engines in the U.S. have established a limit for oxides of nitrogen (NOx) emissions of 0.20 g/bhp-hr., a 90% reduction from the previous emission standards. However, it has been projected that even when the entire on-road fleet of heavy-duty vehicles operating in California is compliant with the 2010 emission standards, the upcoming National Ambient Air Quality Standards (NAAQS) requirement for ambient particulate matter and ozone will not be achieved in California without further significant reductions in NOx emissions from the heavy-duty vehicle fleet. Given this, there is potential of further reduction in NOx emissions limit standards for heavy duty engines in the US. Recently there have been extensive studies and publications focusing on ultra-low NOx after treatment technologies that help achieve up to 0.02g/bhp-hr. at tailpipe [1].

An Automatic Tire Inflation System (ATIS), specifically designed for use on commercial long haul trailers underwent complete testing and evaluation in 1993/1994.1 Testing and evaluation included a field test of a prototype system and a controlled laboratory evaluation of the Rotary Union which is the only component subject to wear. The testing of the prototype system indicated that design improvements were necessary before the system could be installed in fleet operations. The design improvements were completed and field installation of production ATIS began. The design improvements were intended to improve overall system durability, decrease installation time, to have less effect on the axle structure than the original design, implement the use of SAE or DOT Approved pressure components and increase overall dependability of the system. ATIS systems have now been developed and tested for most domestic trailer axle configurations.

Emissions from existing diesel-powered urban buses are increasingly scrutinized as local, state, and federal governments require enforcement of more stringent emission regulations and expectations. Currently, visual observation of high smoke levels from diesel-powered equipment is a popular indicator of potential emission problems requiring tune-up or engine maintenance. It is important that bus inspection and maintenance (I/M) operations have a quality control “test” to check engine emissions or diagnose the engine state-of-tune before or after maintenance. Ideally, the “emission test” would be correlated to EPA transient emissions standards, be of short duration, and be compatible with garage procedures and equipment. In support of developing a useful “short-test,” equipment was designed to collect samples of raw exhaust over a short time period for gaseous and particulate emissions.

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.

The key words in the marketplace for off-highway vehicles are durability, performance, and efficiency. A manufacturer of these vehicles recognizes that one way to successfully address these needs is by a well thought through electronics design. With the computer sophistication now being incorporated into off-highway vehicles, engineers must work closely to assure electromagnetic compatibility (EMC) of the entire system. A properly established EMC program extending from concept to final design will support each of a product's specified operations and still function as an integrated whole. This paper describes the process for designing the EMC for an off-highway vehicle.

Electromagnetic immunity (EMI) for off-highway vehicles (OHV) is a vehicle's ability to resist radiated and conducted electromagnetic interference. Interference can originate within the OHV from the various systems designed to control its operational functions; external sources can also cause serious disruption of the electronic control mechanisms. Knowledge of how and where interferences originate gives the electronic designer insight into how to avoid the pitfalls which can cause malfunctions. Verification of designs through testing will ensure that safety and reliability are built into every OHV produced. This paper discusses the mechanisms that cause susceptibility of electronic circuits to electromagnetic interference, and presents test methods to help the designer improve circuit design and verify the immunity of the complete vehicle. This is the second in a series of papers on electromagnetic compatibility (EMC) in the off-highway vehicle.

Multiple areas in the U.S. continue to struggle with achieving National Ambient Air Quality Standards for ozone. These continued issues highlight the need for further reductions in NOX emission standards in multiple industry sectors, with heavy-duty on-highway engines being one of the most important areas to be addressed. Starting in 2014, CARB initiated a series of technical demonstration programs aimed at examining the feasibility of achieving up to a 90% reduction in tailpipe NOX, while at the same time maintaining a path towards GHG reductions that will be required as part of the Heavy-Duty Phase 2 GHG program. These programs culminated in the Stage 3 Low NOX program, which demonstrated low NOX emissions while maintaining GHG emissions at levels comparable to the baseline engine.

This paper discusses the implications of computerizing the SAE #2 clutch friction durability tests that General Motors Corporation and Ford Motor Company require for automatic transmission fluid certification. There are three reasons for this paper. 1) Friction durability testing is a significant part of a much larger battery of tests needed to qualify a fluid. 2)There have been recent modifications concerning computerization of both the Ford and GM tests. 3) Because there are only two OEM qualified testing facilities, the details of certain testing intricacies in the areas of data acquisition, reduction and reporting may not be as understood as well as in other areas of automotive-based standardized testing. Formulators of automatic transmission fluid need to be aware of all details surrounding the collection and evaluation of the data that will result in the final test report.

This paper reviews the technologies available for Bharat Stage 3 and 4 Heavy Duty on-highway emissions standards. Benchmarking data from several existing engines is used to explore the trade-offs between engine/vehicle cost and fuel consumption. Other implications of the available technologies, such as durability / reliability requirements, are also addressed. The paper provides recommendations for low cost approaches to meeting Bharat Stage 3 and 4 standards with good fuel consumption and reliability/ durability characteristics. A brief look ahead to future Bharat Stage 5 requirements is also provided.

Because of its dominant role in diesel engine performance and emissions, the fuel injection process has become an area of very active research and development. It is now clear that location, shape, rate of development, and mass flow distribution within each fuel jet are all important in controlling fuel air mixing, wall interactions, combustion rate, and the resulting levels of emissions. The objective of this project was to develop an instrument for measurement of the instantaneous fuel mass and momentum distribution in the jets issuing from diesel injection nozzles. The goal was to develop an instrument concept that can be used in the laboratory for fundamental measurements, as well as a quality control system for use in manufacture of the injection nozzles. The concept of the instrument is based on the measurement of the instantaneous momentum of the fuel jet as it impacts on a surface equipped with pressure sensitive elements.

Natural gas-fueled vehicles impose unique requirements on exhaust aftertreatment systems. Methane conversion, which is very difficult for conventional automotive catalysts, may be required, depending on future regulatory directions. Three-way converter operating windows for simultaneous conversion of HC, CO, and NOx are considerably more narrow with gas engine exhaust. While several studies have demonstrated acceptable fresh converter performance, aged performance remains a concern. This paper presents the results of a durability study of eight catalytic converters specifically developed for natural gas engines. The converters were aged for 300 hours on a natural gas-fueled 7.0L Chevrolet engine operated at net stoichiometry. Catalyst performance was evaluated using both air/fuel traverse engine tests and FTP vehicle tests. Durability cycle severity and a comparison of results for engine and vehicle tests are discussed.

An on-line oil consumption measurement system using the SO2 tracer method has characterized automotive gasoline engine oil consumption under various engine operating conditions, including a 200-hour durability test. An oil consumption map of total engine, individual cylinder, and valve train was produced for various speed and load ranges under both steady-state and step-transient operating conditions. The effect of spark timing as an additional engine parameter on the oil consumption was also investigated. Oil consumption maps have enlightened the conventional understanding of oil consumption characteristics and broadened the areas of concern for control technologies. This paper reports the benefit of the on-line oil consumption measurement system, the result of oil consumption history over the durability test, discrete measurement of oil consumption contribution within the engine, and various oil consumption characteristics affected by engine operating conditions.

The purpose in doing probabilistic structural analysis is to provide the designer with a more realistic ability to assess the importance of uncertainty in the structural response. This paper provides an overview of the methodology and discusses validation of modular structural analysis packages capable of predicting the probabilistic response distribution for key structural variables such as stress, displacement, natural frequencies, buckling loads, transient responses, etc. The structural analysis solution is in terms of the cumulative distribution function (CDF). Probabilistic structural analysis methods (PSAM) can be used to estimate structural safety and reliability, while providing the engineer with information on the confidence that should be given to the predicted behavior.