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Experiments were conducted on a turbocharged three cylinder automotive common rail diesel engine with port injection of butanol. This dual fuel engine was run with neat butanol and blends of water and butanol (up to 20% water by mass). Experiments were performed at a constant speed of 1800 rpm and a brake mean effective pressure of 11.8 bar (full load) at varying butanol to diesel energy share values while diesel was either injected as a single pulse or as twin pulses (Main plus Post). Open engine controllers were used for varying the injection parameters of diesel and butanol. Water butanol blends improved the brake thermal efficiency by a small extent because of better combustion phasing as compared to butanol without water. When the butanol to diesel energy share was high, auto-ignition of butanol occurred before the injection of diesel. This lowered the ignition delay of diesel and hence elevated the smoke level.

Use of biodiesel from non-edible vegetable oil as an alternative fuel to mineral diesel is attractive economically and environmentally. Diesel engines emit several harmful gaseous emissions and some of them are regulated worldwide, while countless others are not regulated. These unregulated species are associated with severe health hazards. Karanja biodiesel is a popular alternate fuel in South Asia and various governments are considering its large-scale implementation. Therefore it is important to study the possible adverse impact of this new alternate fuel. In this study, unregulated and regulated emissions were measured at varying engine speeds (1500, 2500 and 3500 rpm) for various engine loads (0%, 20%, 40%, 60%, 80% and 100% rated load) using 20% Karanja biodiesel blend (KB20) and diesel in a 4-cylinder 2.2L common rail direct injection (CRDI) sports utility vehicle (SUV) engine.

Engine oils and their additives are formulated to meet required performance areas such as lubrication, detergency, dispersancy, anti-wear, and so on. Understanding degradation of engine oil additives is important to formulate oils with long time durability. Engine oil additives have been found to affect abnormal combustion in turbocharged gasoline direct injection (TGDI) engines, called low speed pre-ignition (LSPI). Some of metal containing additives such as zinc dithiophosphates (ZnDTP) and molybdenum dithiocarbamates (MoDTC) have been found to reduce LSPI events. In this study, we investigated degradation of ZnDTP and MoDTC in gasoline engine operation and effects of the degradation on LSPI performance.

Commercial Heavy vehicles (CHVs) are an efficient and reliable link between marine, railroad, and air transportation nodes. The vehicle braking power imposes an important constraint in the allowable vehicle speed. The compression brake augments the vehicle retarding power and is currently typically used as an on-off device by experienced drivers. Hardware and software advances allow modulation of the compression brake power through variable valve timing, and thus, enable integration of the compression brake with service brakes. To analyze how much the compression brake affects vehicle speed during braking, we develop a crank angle engine model that describes the intrinsic transient interactions between individual cylinder intake and exhaust gas process, turbocharger dynamics, and vehicle dynamics during combustion and variable brake valve timing. The model is validated using experimental data.

Gasoline direct injection (GDI) technology is already in use in four wheeler applications owing to the additional benefits in terms of better combustion and fuel economy. The air-assisted in-cylinder injection is the emerging technology for gasoline engines which works with low pressure injection systems unlike gasoline direct injection (GDI) system. GDI systems use high pressure fuel injection, which provides better combustion and reduced fuel consumption. It envisages small droplet size and low penetration rate which will reduce wall wetting and hydrocarbon emissions. This study is concerned with a CFD analysis of an air-assisted injection system to evaluate mixture spray characteristics. For the analysis, the air injector fitted onto a constant volume chamber (CVC) maintained at uniform pressure is considered. The analysis is carried out for various CVC pressures, mixture injection durations and fuel quantities so as to understand the effect on mixture spray characteristics.

Better understanding of flow phenomena inside the combustion chamber of a diesel engine and accurate measurement of flow parameters is necessary for engine optimization i.e. enhancing power output, fuel economy improvement and emissions control. Airflow structures developed inside the engine combustion chamber significantly influence the air-fuel mixing. In this study, in-cylinder air flow characteristics of a motored, four-valve diesel engine were investigated using time-resolved high-speed Tomographic Particle Imaging Velocimetry (PIV). Single cylinder optical engine provides full optical access of combustion chamber through a transparent cylinder and flat transparent piston top. Experiments were performed in different vertical planes at different engine speeds during the intake and compression stroke under motoring condition. For visualization of air flow pattern, graphite particles were used for flow seeding.

In this study, 3D air-flow-field evolution in a single cylinder optical research engine was determined using tomographic particle imaging velocimetry (TPIV) at different engine speeds. Two directional projections of captured flow-field were pre-processed to reconstruct the 3D flow-field by using the MART (multiplicative algebraic reconstruction technique) algorithm. Ensemble average flow pattern was used to investigate the air-flow behavior inside the combustion chamber during the intake and compression strokes of an engine cycle. In-cylinder air-flow characteristics were significantly affected by the engine speed. Experimental results showed that high velocities generated during the first half of the intake stroke dissipated in later stages of the intake stroke. In-cylinder flow visualization indicated that large part of flow energy dissipated during the intake stroke and energy dissipation was the maximum near the end of the intake stroke.

Light duty vehicle emission standards are getting more stringent than ever before as stipulated by US EPA Tier 2 Standards and LEV III regulations proposed by CARB. The research in this paper sponsored by US DoE is focused towards developing a Tier 2 Bin 2 Emissions compliant light duty pickup truck with class leading fuel economy targets of 22.4 mpg “City” / 34.3 mpg “Highway”. Many advanced technologies comprising both engine and after-treatment systems are essential towards accomplishing this goal. The objective of this paper would be to discuss key engine technology enablers that will help in achieving the target emission levels and fuel economy. Several enabling technologies comprising air-handling, fuel system and base engine design requirements will be discussed in this paper highlighting both experimental and analytical evaluations.

Current production heavy duty diesel engines have a brake thermal efficiency (BTE) between 43-46% [1]. In partnership with the United States Department of Energy (DOE) as part of the Supertruck 2 program, Cummins has undertaken a research program to develop a new heavy-duty diesel engine designed to deliver greater than 50% BTE without the use of waste heat recovery. A system level optimization focused on: increased compression ratio, higher injection rate, carefully matched highly efficient turbocharging, variable lube oil pump, variable cooling components, and low restriction after treatment designed to deliver 50% BTE at a target development point. This work will also illustrate the system level planning and understanding of interactions required to allow that same 50% BTE heavy duty diesel engine to be integrated with a waste heat recovery (WHR) system to deliver system level efficiency of 55% BTE at a single point.

The influence of big-end bore fretting on connecting rod fatigue fracture is investigated. A finite element model, including rod-bearing contact interaction, is developed to simulate a fatigue test rig where the connecting rod is subjected to an alternating uniaxial load. Comparison of the model results with a rod fracture from the fatigue rig shows good correlation between the fracture location and the peak ‘Ruiz’ criterion, rather than the peak tensile stress location, indicating the potential of fretting to initiate a fatigue fracture and the usefulness of the ‘Ruiz’ criterion as a measure of location and severity. The model is extended to simulate a full engine cycle using pressure loads from a bearing EHL analysis. A fretting map and a ‘Ruiz’ criterion map are developed for the full engine cycle, giving an indication of a safe ‘Ruiz’ level from an existing engine which has been in service for more than 5 years.

Progression of the successful engine program exemplified by the Mack ENDT675 Maxidyne Six, having an essentially constant horsepower characteristic in the operating speed range, has led to the development and production of the new Mack ENDT865, Maxidyne V-8 having similarly ordered performance at higher output. Significant advances in design to maintain reliability at high loadings including a new injection pump, a simplified oil system, and a single turbocharger arrangement are discussed, as well as a new integral engine brake. The Mack Dynatard Engine Brake is specifically covered in the second part of this paper.

The use of alcohol-gasoline blends enables the favorable features of alcohols to be utilized in spark ignition (SI) engines while avoiding the shortcomings of their application as straight fuels. Eucalyptus and orange oils possess high octane values and are also good potential alternative fuels for SI engines. The high octane value of these fuels can enhance the octane value of the fuel when it is blended with low-octane gasoline. In the present work, 20 percent by volume of orange oil, eucalyptus oil, methanol and ethanol were blended separately with gasoline, and the performance, combustion and exhaust emission characteristics were evaluated at two different compression ratios. The phase separation problems arising from the alcohol-gasoline blends were minimized by adding eucalyptus oil as a co-solvent. Test results indicate that the compression ratio can be raised from 7.4 to 9 without any detrimental effect, due to the higher octane rating of the fuel blends.

The heightened interest level in Fuel Economy for Heavy Duty Diesel Engines the industry has seen over the last few years continues to be high, and is not likely to change. Lowering the fuel consumption of all internal combustion engines remains a priority for years to come, driven by economic, legislative, and environmental reasons. While it is generally assumed that lower viscosity grade lubricants offer fuel economy benefits, there is a lot of confusion about exactly what drives the fuel economy benefits. Fuel Economy claims in trade literature vary over a broad range and it is difficult for the end user to determine what to expect when a change in lubricant viscosity is adopted for a fleet of vehicles in a certain type of operation. This publication makes an attempt at clarifying a number of these uncertainties with the help of additional engine test data, and more extensive data analysis.

To establish a criteria for engine oil requirements for Mack diesel engines, a program was conducted to establish a specification based on the use of a production multicylinder engine. Laboratory engine tests were supplemented by field tests to assure correlation. Subsequently modifications were made to the engine test procedures to accommodate modifications in engines being marketed. Oil monitoring and oil analysis programs were also implemented to further assist in assuring adequate engine lubrication.

Prototype selective catalytic reduction (SCR) systems using urea have been demonstrated on diesel trucks in Europe in recent years. In view of upcoming stringent emissions control standards for US HD diesel engines, urea-SCR is being evaluated by US engine and truck manufacturers. The authors and their companies have worked jointly on a project to develop, test, and demonstrate urea-SCR on a US HD diesel engine and Class-8 truck. A prototype urea-SCR system was applied to a 12-liter HD diesel engine. The engine model selected is rated at 350 bhp and is common for highway trucks. The only engine modifications were changes to the injection timing control map in order to better suit the application of the urea-SCR system. This paper details two demonstration phases of the project as follows. The first phase includes recent emissions cell tests using a new compact SCR catalyst and an engine calibration optimized for lower NOX.

In modern engine design, downsizing and reducing weight while still providing an increased amount of power has been a general trend in recent decades. Traditionally, an engine design with superior NVH performance usually comes with a heavier, thus sturdier structure. Therefore, modern engine design requires that NVH be considered in the very early design stage to avoid modifications of engine structure at the last minute, when very few changes can be made. NVH design optimization of engine components has become more practical due to the development of computer software and hardware. However, there is still a need for smarter algorithms to draw a direct relationship between the design and the radiated sound power. At the moment, techniques based on modal acoustic transfer vectors (MATVs) have gained popularity in design optimization for their good performance in sound pressure prediction.

With increasing energy prices and concerns about the environmental impact of greenhouse gas (GHG) emissions, a growing number of national governments are putting emphasis on improving the energy efficiency of the equipment employed throughout their transportation systems. Within the U.S. transportation sector, energy use in commercial vehicles has been increasing at a faster rate than that of automobiles. A 23% increase in fuel consumption for the U.S. heavy duty truck segment is expected from 2009 to 2020. The heavy duty vehicle oil consumption is projected to grow while light duty vehicle (LDV) fuel consumption will eventually experience a decrease. By 2050, the oil consumption rate by LDVs is anticipated to decrease below 2009 levels due to CAFE standards and biofuel use. In contrast, the heavy duty oil consumption rate is anticipated to double. The increasing trend in oil consumption for heavy trucks is linked to the vitality, security, and growth of the U.S. and global economies.

In gasoline direct injection (GDI) engines, air-fuel mixture homogeneity plays a major role on engine performance, especially in combustion and emission characteristics. The performance of the engine largely depends on various engine operating parameters viz., start of injection, duration of injection and spark timing. In order to achieve faster results CFD is becoming a handy tool to optimize and understand the effect of these parameters. Therefore, this study aims on evaluating the two injection parameters viz., single and split injection to evaluate different flame characteristics. Novelty in this study is to define five different parameters which are called α, β, γ, δ and η the details of which are explained in the paper. In order to understand the flame characteristics, these five parameters are found to be very useful. In the present study, a single-cylinder, two-valve, four- stroke engine which is used in two-wheelers in India is considered for carrying out the CFD analysis.

The effect of variation in injection pressure and Injection timing on the performance and exhaust emission characteristics of a direct injection, naturally aspirated Diesel engine operating on Diesel and Diesel-Biodiesel Blends were studied. A three-way factorial design consisting of four levels of injection pressure (150,210, 265,320 bar), four levels of injection timing (19° btdc, 21.5° btdc, 26° btdc, and 30.5° btdc) and five different fuel types (D100, B10, B20, B40, and B60) were employed in this test. The experimental analysis shows that when operating with Linseed Oil Methyl Ester-Diesel blends, we could increase the injection pressure by about 25% over the normal value of 20MPa. The engine performance and exhaust emission characteristics of the engine operating on the ester fuels at advanced injection timing were better than when operating at increased injection pressure.

This work demonstrates how the performance of a standard spark-assisted alcohol engine can be improved by using the Low Heat Rejection (LHR ) concept. The improved combustion is attained by better using the greater heat energy in the combustion chamber of a LHR engine - in this case for the faster vaporisation and better mixing of the alcohol fuels. For this program the LHR engine used has a single cylinder diesel and alcohols sued as sole fuels were ethanol and methanol. For spark assistance an extended electrode spark plug was used and location and projection were optimised for best results. These configurations were evaluated for performance and emissions with and without LHR implementation. The results show that the engine with LHR, ethanol fuel and spark assistance has the highest brake thermal efficiency with the lowest emissions.