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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.

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.

Diesel Engines are known for its low fuel consumption coupled with high specific power output. Downsizing the engines with turbocharging and common rail injection technologies are the recent trends in improving the efficiency and performance of diesel engines. It is very challenging to match the torque targets at low speed and power targets at high speed range of a diesel engines due to system hardware limitation. Torque at lower engine speed will improve a greater extent to the drivability of a vehicle. Formation of black smoke is a major problem in lower engine speeds due lack of air availability. The use of variable geometry, two stage turbocharging and four valves per cylinder are some of the solutions which make the task simpler, also involves additional cost and fundamental design changes. At the same time commonly used waste gate turbocharger for boosting the airflow, fails to deliver required air flow at lower engine speeds.

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.

In the present study, a 17 kW, stationary, direct- injection diesel engine has been converted to operate it as a gas engine using producer-gas and compressed natural gas (CNG) as the fuels on two different operational modes called SIPGE (Spark Ignition Producer Gas Engine) and DCNGE (Dedicated Compressed Natural Gas Engine). The engine before conversion, was run on two other modes of operation, namely, diesel mode using only diesel and producer-gas-diesel-dual-fuel mode with diesel used for pilot ignition. The base data generated on diesel mode was used for performance comparison under other modes to ascertain the fuel flexibility. A technology development and optimisation followed by performance confirmation are the three features of this study. The exercise of conversion to SIPGE is a success since comparable power and efficiency could be developed. DCNGE operation also yielded comparable power with higher efficiency, which establishes the fuel flexibility of the converted machine.

In the present work, investigations were carried out on a single cylinder, low compression ratio, spark-assisted low heat rejection D.I diesel engine. An extended electrode spark plug was used. Performance and emission tests on the engine were carried out with diesel fuel at two compression ratios, 10.5 and 12.5. In each case the engine was tested as a normal engine as well as a low heat rejection engine. The test results show that the low compression ratio spark assisted diesel engine operates very smoothly due to the low peak pressure and low rate of pressure rise. The low heat rejection spark assisted diesel engine gave an improved performance and reduced emissions compared to the normal baseline diesel engine.

The purpose of this study was to assess, by use of computer simulations, the effectiveness of motorcycle helmets in reducing head and neck injuries in motorcyclist impacts. The computer model used was the MVMA Two-Dimensional Crash Victim Simulator. The study investigated a wide variety of impact conditions in order to establish a broad overall view of the effectiveness of helmets. It was found that helmet use invariably reduces dynamic responses which have a role in producing head injury and, in addition, almost always reduces the severity of neck response as well. For no configuration or condition does the helmet greatly increase the likelihood of neck injury. Thus, these simulations of a wide spectrum of motorcyclist impacts provide further evidence that helmet use significantly reduces the likelihood and severity of both head and neck injuries. This study was supported by the Insurance Institute for Highway Safety.

An analysis of the rollover propensity of a make of a TSR used extensively in S.E. Asia roads is presented using a 6-degree of freedom simulation. Verification of the model was against measured accelerations measured over speed breakers. Rollover stability was analyzed through simulating Increasing Steer, NHTSA J Turn, and Road Edge Recovery maneuvers.

A novel Air-Alcohol INDUCTOR with an inherent flexibility to tailor the alcohol flow rate, has been developed for a multi-cylinder, variable-speed, vehicular Diesel engine to enable operation in the Alcohol-Diesel bi-fuel mode. Tests have been carried out on the dynamometer over the whole speed range of the engine. Also road tests have been carried out under constant vehicular speed conditions. Upto 48% Diesel substitution was achieved on road without reduction in thermal efficiency. Laboratory tests indicate lower exhaust temperatures and lower smoke intensities than in the diesel mode.

The contribution of engine borne noise is the major source of vehicle noise in diesel powered vehicles. The engine noise can be minimized by modification of engine components design and also with different acoustic abatement techniques. The research activities were carried out on 4-cylinder CRDe engine for SUV application. All the emission and performance parameters along with combustion noise was captured continuously for all the part load points from 1000 RPM to 2750 RPM with respect to the different road conditions and driving cycle. This paper targets on reducing the combustion noise at the noise prone zones only on the basis of the injection strategies ensuring no ill effect on the emissions and fuel economy. The first step was the reduction of rail pressure which helped noise levels to be reduced by almost 6 dB at noise zones. Main injection timing retardation was tried at all possible zones which influenced in considerable noise reduction at various zones.

The replacement of fossil diesel with neat biodiesel in a compression ignition engine has advantage in lowering unburned hydrocarbon, carbon monoxide and smoke emissions. However, the injection advance experienced with biodiesel fuel with respect to diesel injection setting increases oxides of nitrogen emission. In this study, the biodiesel-NO control is attempted using charge and fuel modification strategies with retarded injection timing. The experiments are performed at maximum torque speed and higher loads viz. from 60% up to full load conditions maintaining same power between diesel and biodiesel while retarding the timing of injection by 3 deg. crank angle. The charge and fuel modifications are done by recycling 5% by volume of exhaust gas to the fresh charge and 10% by volume of methanol to Karanja biodiesel.

Tractor weight transfer is the most common farm-related cause of fatalities nowadays. As in India it is getting mandatory for all safety devices across all HP ranges. Considering any changes in the weight from an attachment such as Rops, PTO device, tow hook and draw bar etc. can shift the center of gravity towards the weight. center of gravity is higher on a tractor because the tractor needs to be higher in order to complete operations over crops and rough terrain. Terrains, attachments, weights, and speeds can change the tractor’s resistance to turning over. This center of gravity placement disperses the weight so that 30 percent of the tractor’s weight is on the front axle and 70 percent is on the rear axle for two-wheel drive propelled tractors and it must remain within the tractor’s stability baseline for the tractor to remain in an upright position.

Oil pump is one of the important engine parasitic loads which takes up engine power through crankshaft to deliver oil flow rate according to engine demand to maintain required oil pressure. The proper functioning of oil pump along with optimum design parameters over various operating conditions is considered for required engine oil pressure. Pressure relief passage is also critical from design point of view as it maintains the required oil pressure in the engine. Optimal levels of oil pressure and flow are very important for satisfied performance and lubrication of various engine parts. Low oil pressure will lead to seizure of engine and high oil pressure leads to failure of oil filters, gasket sealing, etc. Optimization of pressure relief passage area along with other internal systems will also reduce the power consumed by the pump.

Oil pump is one of the important engine parasitic loads which takes up engine power through crankshaft to deliver oil flow rate according to engine demand to maintain required oil pressure. The proper functioning of oil pump along with optimum design parameters over various operating conditions is considered for required engine oil pressure. Pressure relief passage is also critical from design point of view as it maintains the required oil pressure in the engine. Optimal levels of oil pressure and flow are very important for satisfied performance and lubrication of various engine parts. Low oil pressure will lead to seizure of engine and high oil pressure leads to failure of oil filters, gasket sealing, etc. Optimization of pressure relief passage area along with other internal systems will also reduce the power consumed by the pump.

Diesel has been used extensively as fuel for small agricultural engines in India. As natural gas is available in abundance, lot of interest is shown to substitute gas for diesel in these engines either partially or fully. Natural gas has a high Octane rating and hence to replace diesel fully, major irreversible changes in the diesel engine is required. However, in the dual fuel (diesel + gas) system a large percentage of diesel substitution is possible by the addition of the components of the conversion system. A simple dual fuel system has been developed indigenously for this study. Engine tests with dual fuel gas system have been conducted on a single cylinder diesel engine. These results show that the performance of the engine with dual fuel system can almost match that of standard diesel engine.

In order to comply with the stringent future emission mandates of automotive diesel engines it is essential to deploy a suitable combination of after treatment devices like diesel oxidation catalyst (DOC), diesel particulate filter (DPF) and DeNox converter (Lean NOx Trap (LNT) or Selective Catalytic reduction (SCR) system). Since arriving at a suitable strategy through experiments will involve deploying a lot of resources, development of well-tuned simulation models that can reduce time and cost is important. In the first phase of this study experiments were conducted on a single cylinder light duty diesel engine fitted with a diesel oxidation catalyst (DOC) at thirteen steady state mode points identified in the NEDC (New European Driving cycle) cycle. Inlet and exit pressures and temperatures, exhaust emission concentrations and catalyst bed temperature were measured. A one dimensional simulation model was developed in the commercial software AVL BOOST.

The automotive industries around the world is undergoing massive transformation towards identifying technological capabilities to improve vehicle performance. In this regard, the engine dynamic torque plays a crucial role in defining the transient performance and drivability of a vehicle. Moreover, the dynamic torque is used as a visualization parameter in performance prediction of a vehicle to set the right engineering targets and to assess the engine potential. Hence, an accurate measurement and prediction of the engine dynamic torque is required. However, there are very few methodologies available to measure the engine dynamic torque with reasonable accuracy and minimum efforts. The measurement of engine brake torque using a torque transducer is one of the potential methods. However, it requires a lot of effort and time to instrument the vehicle. It is also possible to back-calculate the engine torque based on fuel injection quantity and other known engine parameters.

The effect of different cold- rolling and cryo-rolling routes on the strength and ductility of Al-6061 alloy was thoroughly investigated. Rolling decreased the grain size and increased the strength according to the Hall-Petch relationship. However subjecting the samples to ageing at different temperatures and for different time period increased the strength and improved the ductility. The ductility was improved due to the rearrangement and even decrease in dislocation density due to recovery and recrystallization during ageing while the strength was maintained due to ageing. Evolution of microstructure was investigated by optical microscopy, scanning electron microscopy. Preliminary hardness measurements coupled with tensile tests indicate the improvement of both yield strength and ductility. The disparity in ultimate tensile strength, yield strength and the elongation to failure with different ageing temperatures and for different time period is determined and discussed.