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A prototype 2007 ISL Cummins diesel engine equipped with a diesel oxidation catalyst (DOC), diesel particle filter (DPF), variable geometry turbocharger (VGT), and cooled exhaust gas recirculation (EGR) was tested at Southwest Research Institute (SwRI) under a high-load accelerated durability cycle for 1000 hours with B20 soy-based biodiesel blends and ultra-low sulfur diesel (ULSD) fuel to determine the impact of B20 on engine durability, performance, emissions, and fuel consumption. At the completion of the 1000-hour test, a thorough engine teardown evaluation of the overhead, power transfer, cylinder, cooling, lube, air handling, gaskets, aftertreatment, and fuel system parts was performed. The engine operated successfully with no biodiesel-related failures. Results indicate that engine performance was essentially the same when tested at 125 and 1000 hours of accumulated durability operation.

A technique for evaluating high temperature oxidation and corrosion tendencies of automotive crankcase lubricants is described. The technique utilizes a versatile bench apparatus which, with a minimum of modification, can be used for either evaluating thermal oxidation stability of gear lubricants or oxidation-corrosion tendencies of automotive crankcase lubricants. The apparatus is relatively compact and requires a minimal lubricant sample. Design of the apparatus permits close control of all operating parameters and provides satisfactory test data repeatability. Retainable copper-lead test bearings are used as the indicator in predicting a pass or fail of fully formulated crankcase lubricants as in the case of the CRC L-38-559 (Federal Test Method 3405) technique. Engine and bench test data are compared to illustrate the capabilities of this new bench technique.

The growing usage of Unmanned Aerial Vehicles (UAVs) for aerial surveillance and reconnaissance in military applications calls for lightweight, reliable powerplants that burn heavy distillate fuels. While mass-produced engines exist that provide adequate power-to-weight ratio in the low power class needed for UAVs, they all use a spark-ignited combustion system that requires high octane fuels. Southwest Research Institute (SwRI) has embarked upon an internal research effort to design and demonstrate an engine that will meet the requirements of high power density, power output compatible with small unmanned aircraft, heavy-fuel combustion, reliable, durable construction, and producible design. This effort has culminated in the successful construction and operation of a demonstrator engine.

As on-highway, heavy-duty diesel engine designs have evolved to meet tighter emissions specifications and greater customer requirements, the crankcase environment for heavy-duty engine lubricants has changed. Engine lubricant quality is very important to help ensure engine durability, engine performance, and reduce maintenance downtime. Beginning in the late 1980's, a new Mack genuine oil specification and a new American Petroleum Institute (API) heavy-duty engine lubricant category have been introduced with each new U.S. heavy-duty, on-highway emissions specification. This paper documents the history and development of the Mack T-7, T-8, T-8A, T-8E, T-9, T-10, T-11, and T-12 engine lubricant tests.

More stringent emission legislation has been a driver for changes in the design of Heavy Duty Diesel engines since the 1980s. Optimization of the combustion processes has lead to significant reductions of exhaust emission levels over the years. However, in the year 2002, diesel engines in the USA will have to meet an even more stringent set of emission requirements. Expectations are that this will force most engine builders to incorporate Exhaust Gas Recirculation (EGR). Several studies of the impact of EGR on lubricant degradation have shown increased levels of contamination with soot particles and acidic components. Both of these could lead to changes in lubricant requirements. The industry is developing a new specification for diesel engine lubricants, PC-9, using test procedures incorporating engines with EGR.

This paper describes the design and functionality of an in-situ air entrainment measuring device for analysis of the air entrainment and air release properties of lubricating fluids. The apparatus allows for a variety of measurement techniques for the aeration and deaeration of the lubricating fluid at various temperatures, pressures, and agitation speeds. This test apparatus is patent pending because of its unique ability to allow for continuous, in-situ measurement of the fluid properties and the rates of change of these properties. Most other measurement techniques and apparatuses do not allow for uninterrupted measurement. This apparatus is also unique in that it is capable of detecting minor fluid density changes at a lower level and with more accuracy than all other current techniques or apparatuses.

A menu-driven, PC-based model, ALAMO_ENGINE, has been developed to predict the nitrogen oxides (NOx) reductions in direct-injected, diesel engines due to exhaust gas recirculation (EGR), emulsified fuels, manifold or in-cylinder water injection, fuel injection timing changes, humidity effects, and intake air temperature changes. The approach was to use a diesel engine cycle simulation with detailed gas composition calculations for the intake and exhaust gases (including EGR, water concentration, fuel-type effects, etc.), coupled with a code to calculate stoichiometric, adiabatic flame temperatures and expressions that correlate measured NOx emissions with the flame temperature. Execution times are less than 10 seconds on a 486-66 MHz PC.

A Single Cylinder Medium Speed diesel engine research facility has been developed for investigating areas of current technical concern to the rail, marine and stationary power industries. The design and operation of this Single Cylinder Research Engine (SCRE) is described. The facility is centered around a Bombardier model 251-plus 11.0 L engine which is representative of four stroke multi-cylinder railroad, marine and small stationary powerplant engines. All engine support systems (air, cooling water, fuel oil and lubricating oil pumps) operate independent of the engine enabling a wide range of adjustments in flow, pressure and temperature. Current program areas for which this system is used include alternative fuels evaluation, combustion analyses, fuel injection system development, component wear and durability studies, engine friction analyses, lubricant testing and emissions evaluations.

Chassis dynamometer tests are often used to determine vehicle fuel economy (FE). Since the entire vehicle is used, these methods are generally accepted to be more representative of ‘real-world’ conditions than engine dynamometer tests or small-scale bench tests. Unfortunately, evaluating vehicle fuel economy via this means introduces significant variability that can readily be mitigated with engine dynamometer and bench tests. Recently, improvements to controls and procedures have led to drastically improved test precision in chassis dynamometer testing. Described herein are chassis dynamometer results from five fully formulated engine oils (utilizing improved testing protocols on the Federal Test Procedure (FTP-75) and Highway Fuel Economy Test (HwFET) cycles) which not only show statistically significant FE changes across viscosity grades but also meaningful FE differentiation within a viscosity grade where additive systems have been modified.

Enhancement of fuel/air mixing is one path towards enabling future diesel engines to increase efficiency and control emissions. Air-assist fuel injections have shown potential for low pressure applications and the current work aims to extend air-assist feasibility understanding to high pressure environments. Analyses were completed and carried out for traditional high pressure fuel-only, internal air-assist, and external air-assist fuel/air mixing processes. A combination of analytical 0-D theory and 3D CFD were used to help understand the processes and guide the design of the air-assisted setup. The internal air-assisted setup was determined to have excellent liquid fuel vaporization, but poorer fuel dispersion than the traditional high-pressure fuel injections.

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.

An automated data handling system to assist in the operation of a diesel engine lubricant test laboratory, involving two mini-computers, is described in terms of why it was needed, the design goals sought, and the operating experience which resulted from its use. The concept of two digital systems, one for on-line data logging and another as a ready back-up, as well as a data processor, is discussed. Direct and peripheral benefits which have resulted from the application of the system, such as semi-automated report processing, operational aids, and various engineering applications, are reported.

It is widely acknowledged that the CFR octane rating engines are not representative of modern engines and that there is a gap in the quantification of knock severity between the two engine types. As part of a comprehensive study of the autoignition of different fuels in both the CFR octane rating engines and a modern, direct injection, turbocharged spark-ignited engine, a series of fuel blends were tested with varying composition, octane numbers and ethanol blend levels. The paper reports on the fourth part of this study where cylinder pressures were recorded under standard knock conditions in CFR engines under RON and MON conditions using the ASTM prescribed instrumentation. By the appropriate signal conditioning of the D1 detonation pickups on the CFR engines, a quantification of the knock severity was possible that had the same frequency response as a cylinder pressure transducer.

Stringent emissions regulations and the need for lower tailpipe emissions are pushing the development of low-carbon alternative fuels. H2 is a zero-carbon fuel that has the potential to lower CO2 emissions from internal combustion engines (ICEs) significantly. Moreover, this fuel can be readily implemented in ICEs with minor modifications. Batteries can be argued to be a good zero tailpipe emission solution for the light-duty sector; however, medium and heavy-duty sectors are also in need of rapid decarbonization. Current strategies for H2 ICEs include modification of the existing spark ignition (SI) engines to run on port fuel injection (PFI) systems with minimal changes from the current compressed natural gas (CNG) engines. This H2 ICE strategy is limited by knock and pre-ignition. One solution is to run very lean (lambda >2), but this results in excessive boosting requirements and may result in high NOx under transient conditions.

The primary goal of this project was to characterize particulate emissions from a snowmobile engine through measurement of particulate matter volatile organic fraction (VOF), particle size, and biological activity. Emissions were evaluated using both a mineral oil and a biosynthetic oil. Basic criteria pollutants were also measured from diluted exhaust using conventional techniques. Particulate matter volatile organic fraction was determined using a gas chromatographic method (DFI/GC). Particle size was characterized using a scanning mobility particle sizer (SMPS), and particulate matter biological activity was measured using a modification of the Ames bioassay procedure. Results revealed that more than 99 percent of the particles were ultrafine (Dp<100nm), with a peak concentration in the nanoparticle (Dp<50nm) size range. It was also observed that the use of a biosynthetic lubricant increased both volatile and total PM mass emissions compared to the mineral lubricant.

Many studies on low speed pre-ignition have been published to investigate the impact of fuel properties and of lubricant properties. Fuels with high aromatic content or higher distillation temperatures have been shown to increase LSPI activity. The results have also shown that oil additives such as calcium sulfonate tend to increase the occurrence of LSPI while others such as magnesium sulfonate tend to decrease the occurrence. Very few studies have varied the fuel and oil properties at the same time. This approach is useful in isolating only the impact of the oil or the fuel, but both fluids impact the LSPI behavior of the engine simultaneously. To understand how the lubricant and fuel impacts on LSPI interact, a series of LSPI tests were performed with a matrix which combined fuels and lubricants with a range of LSPI activity. This study was intended to determine if a low activity lubricant could suppress the increased LSPI from a high activity fuel, and vice versa.

The primary objective of this study was to compare the performance of “new” plastic fuel tanks vs. “aged” plastic fuel tanks when subjected to the standard fire exposure test described in ECE R34.01, Annex 5 Section 5.0 “Resistance to Fire.” The program also included a comparison of failure modes of plastic vs. metal fuel tanks when subjected to a simulated post-crash pool fire. The “new” tanks were purchased from the OEM suppliers (not weathered or pre-conditioned with fuel). The “aged” tanks were obtained from vehicles that were operated in a warm climate and considered to be weathered and fully conditioned with fuel. Three vehicle types, representing three fuel tank shapes and installations, were evaluated: 1.) “thin profile” tank, typical of front wheel drive cars with the tank mounted on the underbody near the rear seat area and in front of the rear axle; 2.) “square profile” tank, typical of SUV's with the tank mounted behind the rear axle; and 3.)

Alternative fuels are being evaluated in automotive applications in both commercial and government fleets in an effort to reduce emissions and United States dependence on diesel fuel. Vehicles and equipment have been operated using 100 percent biodiesel and various blends of biodiesel and diesel fuel in a variety of applications, including farming equipment and transit buses. This government study investigates the compatibility of four base fuels and six blends with elastomer and metallic components commonly found in fuel systems. The physical properties of the elastomers were measured according to American Society of Testing and Materials (ASTM) D 471, “Standard Test Method for Rubber Property-Effect of Liquids,” and ASTM D 412, “Standard Test Methods for Rubber Properties in Tension.” These evaluations were performed at 51.7°C for 0, 22, 70, and 694 hours. Tensile strength, hardness, swell, and elongation were determined for all specimens.

This paper describes a new method for measuring oil consumption using laser induced breakdown spectroscopy (LIBS). LIBS focuses a high energy laser pulse on a sample to form a transient plasma. As the plasma cools, each element produces atomic emission lines which can be used to identify and quantify the elements present in the original sample. In this work, a LIBS system was used on simulated engine exhaust with a focus on quantifying the inorganic components (termed ash) of the particulate emissions. Because some of the metallic elements in the ash almost exclusively result from lube oil consumption, their concentrations can also be correlated to an oil consumption rate. Initial testing was performed using SwRI’s Exhaust Composition Transient Operation Laboratory®(ECTO-Lab®) burner system so that oil consumption and ash mass could be precisely controlled.

Impending emissions regulations for diesel engines, specifically exhaust particulate emissions have caused engine manufacturers to once again examine the potential of alternative fuels. Much interest has centered around compressed natural gas (CNG) due to its potential for low particulate and NOx emissions. Natural gas engine development projects have tended toward the use of current gasoline engine technology (stoichiometric mixtures, closed-loop fuel control, exhaust catalysts) or have applied the results of previous research in lean-burn gasoline engines (high-turbulence combustion chambers). These technologies may be inappropriate for foreseeable emissions targets in heavy-duty natural gas engines.