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This paper describes the engine mapping work carried out on a 2.1 litre carburetted petrol engine.The purpose of this work was to improve upon the emission levels of the engine to meet 1996 emission norms with sufficient margin and to achieve best fuel economy possible. This paper deals with the strategy for the selection of speed load points required for mapping depending on engine operating zones, engine base data collection, methodology followed in engine mapping, variation of engine performance and emissions with respect to air/fuel ratio and spark timing etc. Further the mass emission predictions for different strategies like leaning the air/fuel mixture, retarding the ignition timing etc. are also discussed. Recalibration of the carburettor based on the above findings, its effect on vehicle performance are dealt with.

When designing an electric vehicle (EV) traction system, overcoming the issues arising from the variations in the battery voltage due to the state of charge (SoC) is critical, which otherwise can lead to a deterioration of the powertrain energy efficiency and overall drive performance. However, systems are typically documented under fixed voltage and temperature conditions, potentially lacking comprehensive specifications that account for these variations across the entire range of the vehicle operating regions. To tackle this challenge, this paper seeks to adjust an optimal DC-link voltage across the complete range of drive operating conditions by integrating a DC-DC converter into the powertrain, thereby enhancing powertrain efficiency. This involves conducting a comprehensive analysis of power losses in the power electronics of a connected converter-inverter system considering the temperature variations, along with machine losses, accounting for variable DC-link voltages.

The induction process in a stratified engine using swirl was successfully studied by means of an analogous water model using neutral density beads. The studies revealed that the swirl generated by a masked intake valve is characterized by solid body rotation near the center and potential flow in the outer portions. The vortex is unstable and nonsymmetrical with its center of rotation offset from the cylinder axis and forming a helix extending the length of the cylinder.

Small remotely piloted aircraft (10-25 kg) powered by internal combustion engines typically operate on motor gasoline, which has an anti-knock index (AKI) of >80. To comply with the single-battlefield-fuel initiative in DoD Directive 4140.25, interest has been increasing in converting the 1-10 kW power plants in the aforementioned size class to run on lower AKI fuels such as diesel and JP-8, which have AKIs of ~20. It has been speculated that the higher losses (short-circuiting, incomplete combustion, heat transfer) that cause these engines to have lower efficiencies than their conventional-scale counterparts may also relax the fuel-AKI requirements of the engines. To investigate that idea, the fuel-AKI requirement of a 3W-55i engine was mapped and compared to that of the engine on the manufacturer-recommended 98 octane number (ON) fuel.

Automotive manufacturers are facing continuously changing Global environment. Traditionally, these manufacturers relied on structural and general durability tests to validate vehicles. For these tests to remain representative of customer usage in a Global environment, the overall surface conditions of the Global road systems must be studied. Understanding and classifying these road systems conditions is an important step in dealing with vehicle durability in the Global environment. In this paper, an approach to mapping the world road systems into Established Roads (ER) and Developing Roads (DR), utilizing Statistical Discriminant Analysis (SDA), is presented. The classification of Global regions as DR and ER road systems can be effectively used to recommend appropriate development and validation tests for each road system. A few examples are presented to demonstrate how the ER vs.

Dirt entrance on internal combustion engine's air inlet systems are a common issue to fleet owners. Heavy-duty engines are more susceptible to this due its great air volume aspirated. Aiming to avoid it manufacturers employ increasingly resources to conduct research in the field and to develop more efficient air filtration systems to reduce the probability of this occurs. Anyway, the early diagnosis are the best way to avoid expensive damages to the engine. This study aims to explain how fail due dust aspiration occurs and how to interpret periodic oil analysis in order to preserve the power units and reduce the risk of incorrect diagnosis.

Eighteen percent nickel marage steel can be used to fabricate welded airframe structure. The weldability is excellent and the heat treatment is simple. The mechanical properties of marage steel sheet is presented at ambient and elevated temperatures. TIG welded properties are also determined. The adaptation of this alloy for use in a tubular truss weldment is discussed. The tensile, notch tensile, and compressive yield strengths are very good, but the fatigue strength is low compared to a weldable low alloy steel. Marage steel can be used to advantage for high strength, short life applications such as experimental aircraft structure.

A new family of steels, called maraging steels, is being used quite successfully as die casting dies for casting aluminum. The maraging steels were developed for high strength pressure vessel applications such as solid fuel rocket motor cases. These steels have high strength with excellent toughness. In addition, they are relatively easy to heat treat and have good dimensional stability. Repairs by welding are accomplished with relative ease.

Extensive use of mining haulage vehicles with capacities greater than 610,000 kg (120 tons) has created the need for larger front end loaders. This paper describes the design of the L-1200 LeTro-Loader, rated at 17 m3 (22 yd.3), which incorporates an electric propulsion system integrated with an implement hydraulic system.

Marathon LeTourneau’s D-800 rubber tire dozer was developed specifically to meet the high production demands associated with strip mining reclamation. The electric propulsion system (diesel engine, ac generator, wheel motors and solid state control system) design is the same as that used by the L-800, 11.5 M3 (15 yd.3), front end loader. Specific performance and design features of the various systems are discussed.

IN the first part of this paper, read at the March 3, 1938, meeting of the Baltimore Section of the Society, the author discussed the advantages of cab-over-engine trucks as compared with the engine-under-the-hood type, covering much of the same ground included in his earlier paper: “Cab-Over-Engine Trucks-Their Place in Transportation,” published on pages 421-427 of the September, 1937, S.A.E. TRANSACTIONS. At Baltimore Mr. Schon also traced the evolution of transportation by depicting examples of various forms of transportation at different stages in their development; portrayed the progress in allied industries; evaluated the uncontrollable expense increases from greater regulation, higher taxes, and increased pay-rolls; and touched upon dangerous practices and maintenance methods. In the remainder of the Baltimore Section paper, which follows in full, Mr. Schon interprets the trend of commercial-vehicle regulation in the various States, aided by tables showing 1937 changes.

A method for determining margins in conceptual-level design via probabilistic methods is described. The goal of this research is to develop a rigorous foundation for determining design margins in complex multidisciplinary systems. As an example application, the investigated method is applied to conceptual-level design of the Mars Exploration Rover (MER) cruise stage thermal control system. The method begins with identifying a set of tradable system-level parameters. Models that determine each of these tradable parameters are then created. The variables of the design are classified and assigned appropriate probability density functions. To characterize the resulting system, a Monte Carlo simulation is used. Probabilistic methods can then be used to represent uncertainties in the relevant models. Lastly, results of this simulation are combined with the risk tolerance of thermal engineers to guide in the determination of margin levels.

This research makes a new attempt to apply the activated seawater by electrolysis in the development of two-stage wet scrubber system to control the exhaust gas of large marine diesel engines. First, with using only seawater that is naturally alkaline (pH typically around 8.1), the SO2 and SO3 are absorbed by relatively high solubility compared to other components of exhaust pollutants, and PM (Particulate Matter) is removed through direct contact with sprayed seawater droplets. Besides, the electrolyzed alkaline seawater by electrolysis, which contains mainly NaOH together with alkali metal ions (i.e. Na+, Mg2+, Ca2+), is used as the absorption medium of NOx and CO2. Especially, to increase NOx absorption rate into the alkaline seawater, nitric oxide (NO) is adequately oxidized to nitrogen dioxide (NO2) in the acidic seawater, which means both volume fractions are adjusted to identical proportion.

The U. S. Marine Corps, in conjunction with the U. S. Army, is developing a marginal terrain vehicle, based on the airoll principle, to replace the M76 and Ml16 vehicles. The first phase of the XM759 development program established the overall vehicle configuration. Following approval of the basic design, detail design and pilot fabrication were developed. Initial testing was considered unsatisfactory. However, after tire modifications involving a Chevron tread design, slope climbing capability was achieved with no reduction in mobility. Extensive mobility tests have verified that the marginal terrain vehicle can negotiate the most extreme soft soil conditions.

Marine couplings are lubricated either by a continuous flow of oil, or by packing with grease. For an extended, trouble free performance, the selection of the lubricant, as well the maintenance procedures are of utmost importance. While for oil lubrication the main characteristics are viscosity and cleanliness, for grease lubrication the resistance to centrifugal separation is also a factor to be considered.

The basic reason for most marine diesel maintenance problems can be summed up briefly--lack of proper instrumentation. Preventive maintenance is the key to efficient and reliable operation of marine power plants, and this can be effected only by valuable safeguards such as torsion meters, lube pumps, proper inspection, and interpretation of consequent data. Instrumentation and inspection techniques are discussed and related to the responsibilities of both manufacturers and operators.

Briefcase-sized analyzers, originally designed for monitoring emissions from land-based smokestack gases, have been adapted to shipboard use. The results are comparable to those of much larger, rack-mounted devices used on shore, or the multiple instruments used by Lloyd's Register on shipboard. Portable monitors are particularly useful for small vessels, and have been applied to hot exhausts directly out of turbochargers, instead of the usual smokestack measurements. The test protocol evolved during this study will be useful in monitoring diesel engine exhaust emissions, before and after application of emission reduction techniques to assess their efficacy. Initial shipboard testing was conducted on three 82-ft U.S. Coast Guard Cutters (WPBs). The test protocol used was one based on the ISO 8178 procedure (1), taking into account the speeds actually used by the vessels - their operating profile.

Controlling emissions is becompping a more and more important task in the development of diesel engines. So far the most stringent emission limits are valid for landbased power plants. But today the International Maritime Organization (IMO) [1] is close to completing regulations prescribing the upper limits for nitrogen oxides (NOx) emissions from engines running on ships. The new limits are based on the rated engine speed. This paper mainly discusses the results of the research efforts made by New Sulzer Diesel Ltd to achieve the required NOx reductions. The solutions comprise both primary and secondary measures. The various primary measures aim at reducing NOx at the source - the combustion process - whereas secondary measures reduce the NOx emissions produced from the engine by exhaust aftertreatment. The results show that by the year 2000, it is expected NOx limits imposed by the IMO can be met by using well chosen primary methods that are more economical than secondary methods.

The U.S. EPA and the California Air Resources Board have adopted standards to reduce emissions from recreational marine vessels. Existing regulations focus on reducing hydrocarbons. There are no regulations on particulate emissions; particulate is expected to be reduced as a side benefit of hydrocarbon control. The goal of this study was to develop a sampling methodology to measure particulate emissions from marine outboard and personal watercraft engines. Eight marine engines of various engine technologies and power output were tested. Emissions measured in this program included hydrocarbons, carbon monoxide, oxides of nitrogen. Particulate emissions will be presented in a follow-up paper.