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The Cooperative Lubrication Research (CLR) Oil Test Engine, usually called the L-38, has been used for nearly 25 years to evaluate copper-lead journal bearing protection of gasoline rnotoroils under high-temperature, heavy-duty conditions. The test is sensitive to aggressive surface active additives that may encourage bearing corrosion. The L-38 also provides an estimate of oil durability, assessing the resistance of an oil to the accumulation of acidic by-products of combustion that could attack copper-lead bearings. However, the L-38 engine dynamometer test uses a heavily leaded gasoline that is no longer representative of the commercial fuels available in North America, Europe, or Japan. Rather than discard the L-38, this paper describes work to modify the L-38 procedure to run with unleaded gasoline.

Nylon is used as a material in the design of various components of automatic transmissions. Pump rotor guides and thrust washers are among components designed from nylon. Nylon must be compatible with automatic transmission fluid (ATF). An immersion test using nylon strips in various test fluids was developed. The nylon color change was independent of the physical properties (as measured by change of tensile force) of the material. Testing indicated that nylon color change is catalyzed by oxidation effects, and the change in tensile strength is related to thermal degradation. An automatic transmission fluid (ATF) containing calcium sulfonate detergent showed better oxidation resistance and caused less loss of tensile strength in nylon 6 (PA6).

The fuel effects on throttle transients in PFI spark ignition engines were assessed through experiments with simultaneous step change of the throttle position from part load to WOT and increment of the injected fuel amount. The test matrix consisted of various gasoline/methanol blends from pure gasoline to pure methanol, coolant temperatures at 40C (for cold engine condition) and 80C (for warm engine), and different levels of fuel enrichment at the WOT condition. The x-τ model was used to interpret the engine GIMEP response in the transient. Using the model, a procedure was developed to calculate the parameters of the transient from the data. These parameters were systematically regressed against the fuel distillation points, the increment in injected fuel mass in the transient, and the enthalpy required to evaporate the fuel increment as the explanatory variables.

It is found that a thin and rich mixture layer on a wall is formed after impingement of a gas jet of fuel on the wall. The measured thickness of the mixture layer is about 2 mm. and its dispersion rate after the end of injection is much lower, compared to that of a space gas jet. This phenomenon in a small D.I. diesel engine is known as “wall wetting” or “wall fuel accumulation” which has an important influence on engine fuel consumption and emissions. This paper presents a technique for enhancing the near wall mixing of an impinging jet by means of a bump on the wall. The development of a wall jet formed after an impingement of a gas jet has been investigated by simultaneously measuring the near wall velocity and concentration distribution. It has been found that a wall jet is stripped off the wall and ejected as a secondary jet when the wall jet encounters a bump of the wall.

A computational design of experiments was constructed to analyze two basic nozzle designs. Several geometric features of the nozzles such as cavity height, exit orifice area, turbulence generator area and exit orifice position in addition to the pressure differential across the injector were used in a 2k factorial design study. Performance characteristic which were analyzed in an analysis of variance study included the discharge coefficient. atomization efficiency and predicted spray pattern. The computational design of experiments revealed which of the studied parameters had the greatest influence on a given nozzle performance characteristic. These results were compared to a similar investigation which was later performed experimentally from which similar conclusions were drawn.

In the quest for improved fuel efficiency and reduced CO2 emissions, motor manufacturers are increasingly turning to the High Speed Direct Injection (HSDI) diesel engine for passenger car use. To achieve acceptable levels of noise and emissions at low loads two stage injection is being utilised. Such injection systems are prone to nozzle coking due to the small fuel metering holes, low opening pressures and low fuel flow rates under part load operation. This coking leads to a rapid deterioration of emissions performance. This paper describes work done to investigate conditions leading to this phenomena and the possible mechanisms involved.

Many researchers [1,2,3,4] have suggested that lubricants contaminated with soot result in increased rates of wear. Numerous potential mechanisms have been proposed which include abrasion via three body contact, oil starvation and deactivation of the anti-wear additives. It is commonly thought that the control of soot aggregation by the addition of appropriate dispersant additives will lead to improved wear performance [5]. In this paper, the kinematic behaviour of two valve train contacts are studied and a generalised wear model proposed that highlights the importance of oil film thickness, soot particle size and contact mechanics. The results of these analyses when considered alongside the detailed rheological behaviour of the soot laden oil lead us to challenge the significance of soot aggregation and viscosity control to engine wear.

We have found that most commercially available biodegradable hydraulic oils show low static friction coefficients not depending on the kinds of wet friction materials. Since hydraulic motors of a hydraulic excavator contain wet parking brakes, the most commercially available biodegradable hydraulic oils can not provide enough brake torque capacity to park safely. Furthermore, all kinds of commercially available biodegradable hydraulic oils do not have adequate oil performance for a hydraulic system of construction eq ipment. Thus we have developed a n high performance biodegradable hydraulic oil. To obtain a high static friction coefficient and compatibility with elastomers, a new synthetic ester base fluid has been developed. To improve oxidation stability and to attain compatibility with mineral oil based hydraulic oils,. an additive formulation has also been developed.

Diesel fuel was reformulated by reducing sulfur to < 0.005 wt-%, aromatics to < 20 vol-% and by limiting heavy polyaromatics. This reduced NOx, particulate, PAH and mutagenic emissions plus exhaust odor. Oxidation catalysts operated well. Less deposits formed in the EGR system. Fuel lubricity was enhanced by additives evaluated by injection pump tests and HFRR. Three years of field testing with 140 buses showed no fuel related problems. Oil change period could be lengthened and fuel consumption was unchanged. Demand for reformulated fuel was triggered by differentiating taxation based on quality. Fuels have been used since 1993 without problems. Life cycle analysis showed no increase of CO2.

This paper documents the winter and summer testing of a Nissan truck that has been converted to electric drive and specifically designed for cold and damp winter operation. The Nissan pickup truck was driven every day as a commuter vehicle from November 7995 to present time, having logged 7000Km to date. Extensive data and experience provide valuable insights into the design optimization for cold weather performance. Design features to be considered include thermal management of batteries, high grade synthetic lubricants, and low rolling resistance tires. We conclude that an electric vehicle may be used as a personal transportation vehicle; albeit having I l l 0th of the energy in the ‘fuel tank’, EV's can be designed and built to be satisfactorily operated in cold climate conditions.

RESEARCH BY GENERAL MOTORS(ELLIS, 1994) INDICATED THAT THE RANGE OF THEIR PROTOTYPE EV, THE IMPACT, WAS 19 KILOMETERS IN COLD WEATHER. IN OTHER WORDS, THE CAR LOSES OVER 80% OF ITS NOMINAL 21°C RANGE WHEN OPERATED AT-18°C. ACCORDING TO THIS REPORT, POOR EV RANGE IN COLD WEATHER IS A MAJOR IMPEDIMENT TO EV DEPLOYMENT IN NORTHERN REGIONS OF THE COUNTRY. THE NORTHEAST ADVANCED THERMAL MANAGEMENT TECHNOLOGY PROJECT(NATMTP) WAS STARTED TO INCREASE COLD WEATHER RANGE AND IMPROVE PASSENGER COMFORT IN COLD TEMPERATURES. NATMTP, LED BY EVERMONT, FOUND THAT PRODUCTION SOLECTRIA ELECTRIC VEHICLES, MODIFIED WlTH EXISTING TECHNOLOGY SUCH AS FUEL FIRED HEATERS, EXPERIENCED FAR LESS RANGE REDUCTION THAN THAT REPORTED BY ELLIS. ALSO PASSENGER COMFORT IN THESE MODIFIED VEHICLES WAS ACCEPTABLE EVEN IN VERMONT'S BELOW ZERO TEMPERATURES. SOLECTRIA HAS INCORPORATED THE BEST OF THE COLD WEATHER TECHNOLOGIES DEMONSTRATED BY NATMTP INTO ITS 1996 PRODUCTION EV.

Iveco and Shell have collaborated in a test programme on diesel emissions, which has investigated the effect of diesel fuel properties, in conjunction with the effect of fuel injection timing, on the regulated emissions from an advanced heavy-duty diesel engine. This study has contributed complementary information to that generated in the European Programme on Emissions, Fuels and Engine technology (EPEFE). Tests were performed over the R49 (13-mode) European cycle. The experimental programme covered a range of fuel properties, similar to those investigated by EPEFE (density, cetane number, polyaromatics and back-end distillation (T90)), but also included total aromatics. Fuel sulphur content, being relatively well understood with respect to particulate emissions, and in the absence of an oxidation catalyst, was not investigated. Care was taken in the preparation of the fuels to maximise the decorrelation of the selected properties.

The viable environmental car is defined, candidate solutions are reviewed, and an explanation of the recommended solution is presented. The recommended solution, termed “Unlimited Electric,” is the fruit of a study of US driving patterns, target vehicle efficiencies, and advanced battery technologies. Further rationale is derived from the benefits of the vehicle and the avoidance of key consumer burdens associated with many advanced propulsion technologies. The recommended solution is a light, aerodynamic, four-passenger, hybrid vehicle having electric propulsion as the source of acceleration power. Local travel can be performed with zero emissions and there is no need of new fuels or major infrastructure. Energy for long range travel is provided by a small, ultra-low emission, gasoline powered auxiliary power unit integrated with the vehicle.

This paper describes the ongoing homogeneous charge compression ignition (HCCI) research being carried out at Southwest Research Institute (SwRI). Summaries of the results of testing to date are presented and discussed. HCCI is a process whereby a premixed charge of diesel fuel and air is admitted into the power cylinder and compression ignited. Ignition occurs homogeneously throughout the cylinder. HCCI reduces flame temperatures and oxides of nitrogen (NOx) emissions. The lack of fuel rich zones within the cylinder eliminates soot formation (1-pull Bosch smoke numbers of 0, 5-pull = 0). The limits of HCCI start of combustion timing are defined by knock before top dead center (BTDC) and misfire after top dead center (ATDC). Stable and repeatable HCCI combustion has been demonstrated over a wide range of air-fuel (A/F) ratios, intake temperatures, compression ratios (CR), exhaust gas recirculation (EGR) rates, and for two fuels. A/F ratios of 14 to 80 are possible.

Piston heat transfer measurements were taken under varying knock intensity in a modern spark-ignition engine combustion chamber. For a range of knocking spark timings, two knock intensity levels were obtained by using a high (80°C) and a low (50°C) cylinder head coolant temperature. Data were taken with a central and a side spark plug configuration. When the spark-plug was placed at the center of the combustion chamber, a linear variation of peak heat flux with knock intensity was found in the end-gas region. Very large changes in peak heat flux (on the order of 100%) occurred at probes whose relative location with respect to the end gas zone changed from being within (80°C coolant case) to being outside the zone (50°C coolant case). With side spark-plug, distinct differences in peak heat flux occurred at all probes and under all knock intensities, but the correlation between knock intensity and heat flux was not linear.

The Maryland Mass Transit Administration conducted an LNG transit bus demonstration in Baltimore, Maryland. A refueling facility was constructed and maintenance facilities were modified to provide support for the demonstration. During the demonstration operational data were collected on the buses and facilities. Problems encountered with the vehicle LNG fuel systems are reviewed and discussed. This paper summarizes the findings and operation of the LNG fleet during the demonstration and projects future LNG vehicle and operational costs.

A naturally aspirated, direct injection diesel engine was modified in order to be run on dimethyl ether (DME), with a conventional pump-line-nozzle system. The effects of various modifications to engine timing and the injection system as well as EGR were experimentally determined. Compared to the original diesel engine, the NOx emissions were reduced by over 70% through the use of suitable timing, lowered injector opening pressure and EGR. Particulate emissions were very low, and represent over a 90% reduction as compared to the original diesel version. The original pump-line-nozzle injection system was found to be not well suited to DME operation, CO and HC emissions were substantially higher due to secondary injections, caused by high pressure oscillations and residual pressure with the DME.

Even in today's age of underwater nuclear power the majority of the world's submarines still use diesel engines as their main source of mechanical power, as they have done since the turn of the century. The diesel-electric submarine propulsion system has changed little in concept since the start of the Great War of 1914-1919. Diesels are used to provide surface propulsion and underwater power is provided from battery driven motors. Diesels are also used to recharge the batteries when the vessel is on the surface or at snort depth. In the 1939-45 War efforts were made by the Germans to perfect the closed or recycled diesel so that the engine could operate underwater independent of a normal air supply. After sporadic revivals of the idea in recent years, the concept has been brought to technical maturity by British and German engineers. However, the history of the submarine diesel engine and its air-dependent versions are nearly as old as the engine itself.

Nowadays the use of clean fuel on vehicles is actively studied to prevent air pollution in cities. Because of this social need, KIA has developed various vehicles that use alternative fuels[1,2,3,4]. In this study the development of a CNG (Compressed Natural Gas) vehicle that was converted from a 2.0 ℓ Sportage, multi-purpose vehicle, is described. The development of its engine, the conversion of the vehicle, its EMS (Engine Management System), and the reduction of its emissions are discussed.

Long range, extended endurance, variable speed autonomous underwater vehicles (AUVs) appear to be an attractive solution to problems of environmental monitoring, geophysical exploration and military surveillance. To undertake their intended autonomous missions these vehicles require reliable and cost-effective power systems. Although there is presently an extensive interest in untethered AUVs, with far reaching efforts being made in a variety of activities, only limited headway has been made in the development of power systems which could be readily integrated into these vessels. The majority of current research is focusing on increasing the underwater endurance and hence cost effectiveness of the vehicle by developing compact, lightweight high energy density power systems for vessel propulsion. Subsequently, a number of different power systems have been investigated proposed, designed and developed.