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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 present work discusses the developed simulation model aimed to predict the heat rejection (HR) performance and external pressure drop characteristics of automotive charge air cooler (CAC). Heat rejection and airside pressure drop characteristics of CAC were predicted for the conditions of different charge air mass flow rates and different cooling air velocities. The lack of detailed research on CAC performance prediction has motivated the development of the proposed simulation model. The present 1-D simulation has been developed based on the signal library of AMESIM application tool. Input parameters for this simulation such as core size, tube pitch, tube height, number of tubes, fin density, louver angle, louver pitch, charge air mass flow rate, cooling air velocity, charge air inlet temperature, and ambient temperature. Heat rejection curve and airside pressure drop of CAC were the output of the present simulation.

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.

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.

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 air velocity achieved at driver and passenger aim point is one of the key parameters to evaluate the automotive air-conditioning system performance. The design of duct, vent and vanes has a major contribution in the cabin air flow directivity. However, visual appearance of vent and vane receives higher priority in design because of market demand than their performance. More iterations are carried out to finalize the HVAC duct assembly until the target velocity is achieved. The objective of this study is to develop an automated process for vane articulation study along with predicting the optimized velocity at driver and passengers. The automated simulation of vane articulation study is carried out using STAR-CCM+ and SHERPA optimization algorithm which is available in HEEDS tool. The minimum and maximum vane angle are defined as parameters and face level velocity is defined as response.

In recent time, with inception of BS VI emission regulation with more focus on fuel economy and emission, many engine parts which were conventionally made from metal are getting replaced with plastic components for reducing weight to attain better fuel economy. EGR is commonly used technique to reduce emissions in diesel engine along with after treatment devices. EGR reduces peak combustion temperature inside the combustion chamber thereby reducing NOx. EGR is bypassed from the exhaust manifold, cooled down in EGR cooler and mixed with intake air at upstream of the intake manifold. Throttle valve is used for controlling the charged air flow to cylinders for different vehicle operating conditions. With compact engine layout EGR mixer are often located near to throttle valve thereby increasing the possibility of soot deposition on throttle valve.

Condition Monitoring is the process of identifying any significant change in operating parameters of a machine, which can be indicative of a failure in future. This paper discuss a non-invasive condition monitoring methodology for sensing and investigating the problems which could be identified by noise and vibrations. This could be an easy solution for predicting failures in tractors which are operational in the field. An example of engine tappet is used to demonstrate the methodology. A disturbed setting causes a distinguishable noise, referred to as “tappet rattle”. Android smartphones (with inbuilt sensors - accelerometer, gyroscope and microphone) are used to record noise and vibration from tractors in good condition as well as in disturbed condition. Time series data analysis is done to extract relevant features and then Fourier Transform is applied to the signals for extracting frequency domain signatures.

Computer Aided Engineering (CAE) simulations are an integral part of the product development process in an automotive industry. The conventional approach involving pre-processing, solving and post-processing is highly time-consuming. Emerging digital technologies such as Machine Learning (ML) can be implemented in early stage of product development cycle to predict key performances without need of traditional CAE. Oil Canning loadcase simulates the displacement and buckling behavior of vehicle outer styling panels. A ML model trained using historical oil canning simulation results can be used to predict the maximum displacement and classify buckling locations. This enables product development team in faster decision making and reduces overall turnaround time. Oil canning FE model features such as stiffness, distance from constraints, etc., are extracted for training database of the ML model. Initially, 32 model features were extracted from the FE model.

Lubrication systems play a major role not only in the durability of modern IC engines but also in performance and emissions. The design of the lubrication system influences the brake thermal efficiency of the engine. Also, efficient lubrication reduces the engine's CO2 emissions significantly. Thus, it is critical for an IC engine to have a well-designed lubrication system that performs efficiently at all engine operating conditions. The conventional lubrication system has a fixed-displacement oil pump that can cater to a particular speed range. However, a fully variable displacement oil pump can cater to a wide range of speeds, thereby enhancing the engine fuel efficiency as the oil flow rates can be controlled precisely based on the engine speed and load conditions. This paper primarily discusses the optimization of a lubrication system with a Variable Displacement Oil Pump (VDOP) and a map-controlled Piston Cooling Jet (PCJ) for a passenger car diesel engine.

The Introduction of Corporate Average Fuel Economy (henceforth will be addressed as CAFE) regulations demand suitable technological upgrades to meet the significant increase in targets of vehicle fleet fuel economy. Engine Downsizing and Friction Reduction measures help in getting one step closer to the target. In a Conventional Oil Pump, the pump discharge flow and pressure are a direct function of operating speed. There is no control over lubricant flow which results in increased power and fuel consumption due to its unnecessary pumping characteristics irrespective of the actual engine demand. This paper discusses the introduction of a variable displacement oil pump (henceforth will be addressed as VDOP) that was adapted to a 1.5-liter 3 Cylinder Diesel Engine. This approach helps the system to reduce parasitic losses as the oil flow is regulated based on the mechanical needs of the engine. The flow is regulated with help of a solenoid valve which receives input from the ECU.

Design and development of high-pressure pipe involves number of design validation plans for robust design in diesel engine. The fundamental behavior of two-cylinder diesel engine with parallel stroke involves high vibration which generates stress on components mounted on crankcase resulting into earlier fatigue failure. In this paper, the innovative approach of using optimized design of vibration damper for resolving high vibration stress concerns in fuel system is discussed. The vibration dampers were designed meeting both performance and durability aspects in two-cylinder diesel engine applicable for both passenger and commercial vehicle. This paper highlights the design approach involving experimental stress measurements and design optimization based on part development feasibility.

Globally, automotive sector is moving towards improving off-road performance, durability and safety. Need of off-road performance leads to unpredictable overload to powertrain system due to unpaved roads and abuse driving conditions. Generally, shafts and gears in the transmission system are designed to meet infinite life. But, under abuse condition, it undergo overloads in both torsional and bending modes and finally, weak part in the entire system tend to fail first. This paper represents the failure analysis of one such an incident happened in output shaft under abuse test condition. Failure mode was confirmed as torsional overload using Stereo microscope and SEM. Application stress and shear strength of the shaft was calculated and found overstressing was the cause of failure. To avoid recurrence of breakage, improvement options were identified and subjected to static torsional test to quantify the improvement level.

Light weight and Robust manufacturing technologies are always needed for transformation drive in the Automotive industry for the next-generation vehicles with greater Power to weight ratio. Innovations and process developments in materials and manufacturing processes are key to this light weighting transformation. Aluminium material has been widely used for these light weighting opportunities. However, aluminum joining techniques, characterized by their poor quality and consistency are limiting this transformation. This technical paper represents one of such case, where the part is made up of Aluminium through conventional casting route which has affected the laser weld quality due to poor casting soundness. This experiment explains in detail about the importance of Casting soundness for laser weld quality, weld penetration, strength etc., and the Product consistency.

Diesel engines are known for their excellent low-end torque, better drivability, performance, and better fuel economy. The increase in customer demands pushes to deliver higher power and torque along with fuel economy. This requirement puts a great challenge on the overall weight of the engine. This paper explains the holistic approach followed along with optimizing the rocker arm cover to achieve the weight target without compromising on durability and cost in the commercial segment 2.5-liter Diesel Engine. This paper presents a complete overview of the design and development of Rocker Arm (RA) cover to meet Strength, Durability, NVH and Aesthetic in Commercial Engine where base design is in aluminum which is mounted on cylinder head with a separate breather system. From aluminum the base design of Rocker arm cover is optimized to sheet metal where in there is reduction of 43% in weight and cost saving of 13%.

For meeting the stringent BS VI emissions in a 3-cylinder diesel engine the Exhaust after treatment system (EATS) was upgraded from a single brick DOC (diesel oxidation catalyst) to 2 brick DOC+sDPF (Diesel Particulate Filter) configuration. To meet the demands of emission regulation and sDPF requirements, changes were also required in the Fuel injection system. Major changes were done to the fuel injector and fuel pump. This paper primarily discusses the Fuel injector change from 1.1 to 2.2 family with changes in nozzle geometry, Nozzle tip protrusion (NTP), and injector cone angle and the effects on the emission and performance parameters. The various design values of NTP, cone angle, and Sac values are tested in an actual engine to meet the required power, torque and verified to meet NOx, HC, PM values as required by the new BS (Bharat Stage) VI regulation. Other boundary conditions are also checked - BSFC (Brake Specific Fuel Consumption), temperature, etc.

The combustion strategies play a key role in emission improvisation and noise reduction on diesel engines equipped for higher emission norus. This paper clearly discussed on the selection of various operating points for optimization and employing of proper calibration strategies like pilot strategy, Main injection timing, EGR type and rail pressure variation for best emission and noise output. Various optimization techniques have been implemented in our study. Since the pilot injection quantity as well as timing are varied in our paper, careful matrix formulation is required to determine the best optimum point. Around 340 points were obtained on varying pilot quantity and pilot separation sweep chosen at single engine speed and load for both the pilots. Out of the above points, 5 sensitive points were selected ensuring the sensitivity of the emissions and noise.

The combustion phenomenon of diesel engines has got a very major impact on the performance and exhaust emission levels. Several important factors like engine components design, combustion chamber design, Exhaust gas recirculation, exhaust after treatments systems, engine operating parameters etc. decide the quality of combustion. The role of fuel injector is crucial on achieving the desired engine performance and emissions. Efficient combustion depends on the quantity of fuel injected, penetration, atomization and optimum timing of injection. The nozzle through flow, cone angle, no of sprays and nozzle tip penetration are the factors which lead to the selection of perfect injector for a given engine. This paper focusses on the selection of the best fit injector suiting the BS6 application on evaluating the performance and emission characteristics. Injectors used were with varying cone angles and NTP.