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RADIATION can produce almost instantaneous failure of modern aircraft lubricants, tests at Southwest Research Institute show. Two types of failures demonstrated are rapid viscosity rise and loss of heat conductivity. Furthermore, it was found that lubricants can become excessively corrosive under high-level radiation. Generally speaking, the better lubricants appeared to improve in performance while marginal ones deteriorated to a greater extent under radiation. When the better lubricants were subjected to static irradiation prior to the deposition test, there was a minor increase in deposition number as the total dose was increased.

Transmission spin loss has significant influence on the vehicle fuel economy. Transmission output chain may contribute up to 10~15% of the total spin loss. However, the chain spin loss information is not well documented. An experimental study was carried out with several transmission output chains and simulated transmission environment in a testing box. The studies build the bases for the chain spin loss modeling and depicted the influences of the speed, the sprocket sizes, the oil levels, the viscosity, the temperatures and the baffle. The kriging method was employed for the parameter sensitivity study. A closed form of empirical model was developed. Good correlation was achieved.

Radioactive tracer technology is an important tool for measuring component wear on a real-time basis and is especially useful in measuring engine wear as it is affected by combustion system operation and lubricant performance. Combustion system operation including the use of early and/or late fuel injection and EGR for emissions control can have a profound effect on aftertreatment contamination and engine reliability due to wear. Liner wear caused by localized fuel impingement can lead to excessive oil consumption and fuel dilution can cause excessive wear of rings and bearings. To facilitate typical wear measurement, the engine's compression rings and connecting rod bearings are initially exposed to thermal neutrons in a nuclear reactor to produce artificial radioisotopes that are separately characteristic of the ring and bearing wear surfaces.

Radioactive tracer technology (RAT) is an important tool in measuring component wear in an operating engine on a real-time basis. This paper will discuss the use of RAT to study and evaluate boundary lubricant and surfactant chemistries aimed at providing benefits in wear control. In particular, RAT was employed to study ring and bearing wear as a function of engine operating condition (speed, load, and temperature) and lubricant characteristics. Prior to testing, the engine's compression rings and connecting rod bearings were subjected to bulk thermal neutron bombardment in a nuclear reactor to produce artificial radioisotopes that were separately characteristic of the ring and bearing wear surfaces. The irradiated parts were installed in the test engine, after which testing to a specific test matrix was accomplished.

A unique and attractive variator mechanism has been developed by Turbo Trac, Inc. and Southwest Research Institute (SwRI) for initial use in a heavy duty diesel truck application. High efficiency levels have been predicted with analytical models and confirmed with actual test data. Further, this variator incorporates a very stable and simple control system and has extremely high torque capacity. The prototype of the variator mechanism has also been configured with a modified Allison 650 series transmission for use as a series application in a Peterbilt truck, the final configuration will be a split power design. The setup includes a preliminary control system that allows for highway driving. It is emphasized, however, that Allison did not contribute to this design or any of the content of this paper.

Several techniques have been developed to measure the relative amount of splash and spray produced by vehicles when driven on wet roads at highway speeds under controlled conditions. This paper discusses considerations in the development of measurement techniques such as those utilizing photographs, a photometer, densitometer, spraymeter, and spray collector. The development of each technique is described. Some test data utilizing the photometer and densitometer techniques are presented in a comparison of two different trucks run on two different road surfaces with new and worn tires, fully loaded and unloaded, and under light and heavy road moisture conditions.

A study was performed to develop optimum design strategies for a production V6 engine to maximize catalyst performance at minimum pressure loss and at minimum cost. Test results for an advanced system, designed to meet future emission limits on a production V6 vehicle, are presented based on FTP testing. The on-line pressure loss and temperature data serves to explain the functioning of the catalyst.

Pouch cells are increasingly popular form factors for the construction of energy storage systems in electric vehicles of all classes. Knowledge of the stress generated by these higher capacity pouch cells is critical to properly design battery modules and packs for both normal and abnormal operation. Existing literature predominantly offers data on smaller pouch cells with capacities of less than 10 Ah, leaving a gap in our understanding of the behavior of these larger cells. This experimental study aimed to bridge this knowledge gap by measuring loads and stresses in constrained 65 Ah pouch cells under both cycling and abuse conditions. To capture the desired responses, a load cell was located within a robust fixture to measure cell stress in real time after the application of a preload of approximately 30 kilograms or 294 N, equivalent to a pressure of 0.063 bar, with a fixed displacement.

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 optical spark plug probe and ionization head gasket probe developed at Sandia Laboratories were applied to one cylinder of a production multicylinder automotive gasoline engine. The purpose of this application is to eventually study combustion phenomena leading to high emissions under cold start and cold idle conditions. As a first step in studying cold start combustion and emissions issues, diagnostic instrumentation was simultaneously applied to a production engine under steady state idle, road load and an intermediate load-speed condition. The preliminary application of such instrumentation is the subject of the present paper. The spark plug probe was redesigned for ease of use in production engines and to provide a more robust design. The two probes were geometrically oriented to obtain radial line-up between the optical windows and ionization probes. Data were taken simultaneously with both probes at the three load-speed conditions mentioned above.

The U.S. Army's National Automotive Center has contracted with Illinois Institute of Technology Research Institute (IITRI), Southwest Research Institute (SwRI), and Advanced Propulsion, LLC, to evaluate the effects on fuel consumption and logistics that would result from hybridizing the powertrains of the Army's tactical wheeled vehicle fleet. This paper will outline the approach taken to perform that evaluation and present a synopsis of results achieved to date.

Real-time transient and steady-state oil consumption were measured on three SI-engines, applying two different ring-packs to each engine. Testing of multiple engines enables an assessment of the engine-to-engine variability in oil consumption. Testing of multiple ring-packs on each engine enables an assessment of the ring-pack-to-ring-pack variability in oil consumption. The oil consumption was measured by the Southwest Research Institute (SwRI) novel developed SO2-tracer technique, referred to as RTOC-III. An interesting finding is that the testing shows low engine-to-engine and ring-pack-to-ring-pack variability, in both steady-state, as well as in transient oil consumption. This suggests that the RTOC-III system did not introduce significant variability to the data. The testing results are experimental verification of a design and simulation exercise, in a field of scarcely published literature.

Increased concern for improving fuel mileage in today's vehicles has focused attention on powertrain component efficiencies. Currently, no efficiency standards exist for automatic transmissions but, uniform testing procedures do exist. Consequently, vehicle and transmission manufacturers have no basis for comparing transmission-to-transmission performance. In addition, manufacturers have no design targets from which to critique their product. This paper addresses this issue by developing an overall transmission efficiency rating. This rating is based upon average transmission operational torques and speeds, the percent time of operation in each gear for a representative duty cycle, and representative efficiencies at these conditions based on test data obtained from a cross section of current production transmissions.

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.

A Dodge Omni electric car was prepared for competition in an electric “stock car” 2-hour endurance event: the inaugural Solar and Electric 500 Race, April 7, 1991. This entry utilized a series-wound, direct-current 21-hp electric motor controlled by an SCR frequency and pulse width modulator. Two types of lead-acid batteries were evaluated and the final configuration was a set of 16 (6-volt each) deep-cycle units. Preparation involved weight and friction reduction; suspension modification; load, charge and temperature instrumentaltion; and electrical interlock and collision safety systems. Vehicle testing totalled 15 hours of operation. Ranges observed in testing with the final configuration were from 30 to 52 miles for loads of 175 to 90 amperes. These were nearly constant, continuous discharge cycles. The track qualifying speed (64mph) was near the 68 mph record set by the DEMI Honda at the event on the one-mile track.

Upcoming regulations from CARB and EPA will require diesel engine manufacturers to validate aftertreatment durability with full useful life aged components. To this end, the Diesel Aftertreatment Accelerated Aging Cycle (DAAAC) protocol was developed to accelerate aftertreatment aging by accounting for hydrothermal aging, sulfur, and oil poisoning deterioration mechanisms. Two aftertreatment systems aged with the DAAAC protocol, one on an engine and the other on a burner system, were directly compared to a reference system that was aged to full useful life using conventional service accumulation. After on-engine emission testing of the fully aged components, DOC and SCR catalyst samples were extracted from the aftertreatment systems to compare the elemental distribution of contaminants between systems. In addition, benchtop reactor testing was conducted to measure differences in catalyst performance.

The effects of carbon black∕diesel fuel slurries on fuel injection systems and performance of an EMD 567B two-cylinder locomotive research engine when operated on slurry fuel are presented in this paper. Without extensive modification to the diesel engine fuel transfer system, carbon black slurries cannot be run. Laboratory bench tests revealed clogged fuel filters, worn transfer pump components and frozen injector needle assemblies. Engine performance while running slurries resulted in reduced thermal efficiency and increased BSFC at rated power output. Upon engine disassembly, inspection revealed severe ring and liner wear. Severe wear resulted during only 40 hours of engine operation.

It is generally recognized chat methanol is the best candidate for long-term replacement of petroleum-based fuels at soma time in the future. The transition from an established fuel to a new fuel, and vehicles that can use the new fuel, is difficult, however. This paper discusses two independent investigations of possible transition uses of methanol, which, when combined, may provide an option for introduction of methanol that takes advantage of the existing industrial base, and provides economic incentives to the consumer. The concept combines the intermediate blends of methanol and gasoline (50%-70% methanol) with the Flexible Fuel Vehicle. In addition to a possible maximum cost effectiveness, these fuels ease vehicle range restrictions due to refueling logistics, and mitigate cold starting problems, while at the same time providing most of the performance of the higher concentration blends.

In off-highway applications the engine torque is distributed between the transmission (propulsion) and other accessories such as power steering, air conditioning and implements. Electronic controls offer the opportunity to more efficiently manage the control of the engine and transmission as an integrated system. This paper deals with development of a steepest descent algorithm for maximizing the efficiency of hydrostatic transmission along with the engine in the presence of accessory load. The methodology is illustrated with an example. The strategy can be extended to the full hydro-mechanical configuration as required. Applications of this approach include adjusting for component wear and intelligent energy management between different accessories for possible size reduction of powertrain components. The potential benefits of this strategy are improved fuel efficiency and operator productivity.

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.