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Air pollution in India and also global warming are two major concern in the country. To address this situation, India is moving from BS-IV to BS-VI for on-road applications with 90% reduction in NOx and 50% in PM with limit on particulate number. Also moving to Trem-IV and Trem-V for off-road applications subsequently. It needs higher efficiency after-treatment systems like SCR and DPF to achieve such lower emission levels. Addition of these complex after-treatment system, severely increase the cost of diesel power plant with heavy penalty on fuel economy. Hence, it is challenge to auto industry to reduce the complexity and cost, so that it requires an alternate solution to reduce NOx and PM emissions at source to reduce cost and system complexity. Low Temperature Combustion (LTC) is a potential concept to reduce the NOx and PM emissions simultaneously.

In today’s ever-changing scenario, gasoline engine is going to be more acceptable passenger vehicle prime mover, as it meets Bharat Stage-VI (BS-VI) emission standard and need less cost of up-gradation. Variable cam phasing (VCP) system is well known & proven advanced technology in automotive world, which already used by many OEMs globally to improve fuel consumption and reduce engine emissions. Electric Cam Phasing (ECP) is an integration of electro-mechanical system. In ECP, angle shifting is independent of engine oil pressure, which allows a more aggressive engine calibration of valve timing to minimize active intervention in the ignition and fuel injection sequences. Early advance timing makes it possible for the combustion engine to build up torque more quickly during acceleration, which means that ECP not only helps to achieve high operating efficiency, but also good driving performance.

Direct injection and jet ignition is becoming popular in electrically assisted, turbocharged, F1 engines because of the pressure to reduce fuel consumption. Operation from homogeneous stoichiometric up to lean of stoichiometry stratified about λ = 1.5, occurs with fast combustion of reduced cyclic variability thanks to the enhanced ignition by multiple jets of hot, partially reacting products travelling through the combustion chamber. The fuel consumption has thus been drastically reduced in an engine that is, however, still mostly throttle controlled. The aim of the present paper is to show the advantages of direct injection and jet ignition based on model simulations of the operation of a high-performance throttle-controlled engine featuring rotary valves.

The head gasket of an internal combustion engine acts as a critical seal between its cylinder block and heads. Typically, and ideally, a high horse power engine head gasket will be composed of elastomer fluid sealing elements in a carrier and combustion seal body composed of aluminum, brass, carbon steel, copper, nickel, and/or stainless steel etc. The head gaskets purpose is to seal high pressure combustion gases, coolant, and oil and to ensure no leakage of gases or fluids out of the block to head joint. Three major failure modes [1] for cylinder head gasket joint are; 1. Fluid or gas leakage due to low sealing pressure. 2. Head gasket (bead) cracking due to high gap alternation and 3. Gasket scrubbing/fretting due to pressure and temperature fluctuations causing relative movement in the joint. During engine operation, the head gasket design should be robust enough to prevent all failure modes and provide acceptable performance.

Squeak and rattle concerns account for approximately 10% of overall vehicle Things Gone Wrong (TGW) and are a major quality concern for automotive OEM’s. Seat is one of the major contributors of squeak and rattle issues observed in customer verbatim. Seat head rest rod and bezel are designed concentric to each other with a gap that allows free movement and a locking pin to position at different levels. Due to the design gap and weight of the head rest there is always tendency for relative displacement leading to rattle issues. Seat headrest, is close to the customer ear and any rattles at headrest will create annoying driving experience. Also, the contradictory requirements between efforts and rattle makes the scenario more difficult to fine tune the bezel specifications. The root cause for head rest rattle issues can also be related to free play between bezel and seat frame, free play between bezel and cap, looseness between locking pin and headrest rod etc.

Optimizing noise control treatments in the early design phase is crucial to meet new strict regulations for exterior vehicle noise. Contribution analysis of the different sources to the exterior acoustic performance plays an important role in prioritizing design changes. A method to predict Pass-by noise performance of a car, based on source-path-receiver approach, combining data coming from simulation and experimental campaigns, is presented along with its validation. With this method the effect of trim and sound package on exterior noise can be predicted and optimized.

The gap between the officially reported CO2 values and the actual performance of the vehicle on the road is continuously increasing. Numerous studies are showing differences between the official values and the real-world measurements of more than 40% in average, with further increases year by year. The fuel consumption of passenger cars are determined as part of the vehicle certification according to Euro 6 via carbon mass balance using exhaust gas measurement. By introducing the new world harmonized driving cycle (WLTC) in September 2017, which is addressing a more realistic speed profile or traffic conditions, the gap between the certification and road test is expected to be reduced in half. Additionally the EU Commission plans to monitor vehicles more closely. From 2020, devices for recording fuel and energy consumption will become mandatory in all passenger cars and light commercial vehicles, reflecting the average real world CO2 emissions.

Most stringent emission legislations have been implemented in all major markets to improve air quality across the past years. This effects the product cost of the vehicles which is considered being critical and needs to be minimized. India suffers from bad air quality and countermeasures have been defined. One being the implementation of similar emission standards than EU VI. By doing so, India takes a large step going from the currently effective BS IV directly to BS VI. Emission reduction is currently mainly handled by the usage of EGR, thus no engine aftertreatment system has been applied. BS VI will require an aftertreatment (EAS) concept with several catalysts and corresponding control system. India is a very cost sensitive market and a carry over of solutions from the EU needs to be evaluated carefully and new approaches need to be found.

Gearshift quality is a perceived quality parameter. Hence, is getting much importance because of the increased awareness about comfortable and refined driving experience, especially in the case of passenger cars. When the topic of gearshift feeling is broached in manual transmission vehicles, synchronizer pack (shifter sleeve, engaging gear, strut, synchronizer and gear synchro ring assembly) have been the focus point for optimization. Synchronizer type (single, double or triple cone), lining material, datch chamfer angle of shifter sleeve/synchro ring of gear/synchronizer, all of these have been extensively studied in the past to improve the gearshift quality. With stringent timelines for vehicle development, OEMs prefer to use off-the-shelf powertrain systems developed by powertrain manufacturers. Due to this, avenues to refine gearshift feel gets reduced to a large extent and hence refinement becomes difficult.

Engine braking is a supplemental retarding technology in addition to foundational friction brakes in commercial vehicles. This technology is in use in Europe & Americas for several decades now. In engine braking, the engine acts as a compressor, thus producing the required braking power. The braking power is generated by either reducing the volumetric efficiency or increasing the pressure difference across the cylinder. This is usually achieved by means of exhaust valve lift modulation. There are dominantly two types of engine brakes viz. bleeder brake and compression release brake. The present work uses GT-Power® model to study the braking performance of a 4-cylinder, medium duty diesel engine at different engine RPMs and valve lifts. The work brings out a comprehensive understanding of different lift events and their effects on braking performance.

Diesel engine generators are commonly used as a power source for various industrial and residential applications. While designing diesel generator (DG) enclosures requirements of noise control, ventilation and physical protection needs to be addressed. Indian legislation requirement demands DG enclosure insertion loss (IL) to be minimum 25 dB. However for certain critical applications like hospitals, residential apartments customer demands quiet DG sets than the statutory limits. IL targets for such application ranges between 35-40 dB. The objective of this paper is to develop methodology to design ‘Super Silent’ enclosure with IL of 35 dB by Statistical Energy Analysis (SEA) approach for small capacity DG set. Major challenge was to achieve IL of 35 dB with single enclosure and making use of SEA technique for small size enclosure wherein modal densities is very less. Major airborne noise sources like engine, radiator fan and exhaust were modelled by capturing noise source test data.

Breather assembly is mounted on transmission to maintain the pressure equilibrium inside transmission. Breather allows the transmission to breathe air when the air inside transmission expands or contracts due to heating and cooling of lubricating oil during vehicle running. Breather allows the hot air to escape and cool air to enter into the transmission to prevent overheating issue. Failure of breather assembly can lead to pressure buildup inside transmission and further leading to leakage from transmission oil seals. Oil leakage through the breather assembly is governed by parameters such as opening pressure, location and orientation of breather etc. The transmission undergoes different operating conditions of input speed, load, temperature, inclination etc. Also, breather assembly is designed and positioned in such a way that there is no leakage through breather due to oil splash inside the transmission.

The use of polymers in automobiles is increasing constantly and this trend is expected to continue. This clearly indicates that polymer are choice of materials in all the application sectors including in Automobile sector. The main properties in selecting the plastics materials as compared to other materials applied in automobiles are the aesthetic of automotive vehicles, their functionality and cost effective solution, as well as fuel efficiency. These materials are offer remarkable range of appealing properties, the effect of climatic conditions on the degradation and performance of these materials is not fully understood. It is necessary to know the variation of the mechanical properties of any polymer component in automobile after exposed to different atmospheric conditions before particular application. Generally when these components are subjected to weathering effects, they are prone to underperform.

Future emission limits for off-highway application engines need advanced power train solutions to meet stringent emissions legislation, whilst meeting customer requirements and minimizing engineering costs. DI diesel engines with four valves per cylinder are widely used in off- highway applications because of the fundamental advantages of higher volumetric efficiency, lower pumping loss, symmetric fuel spray & distribution in combination with the symmetric air motion which can give nearly optimal mixture formation and combustion process. As a result, the fuel consumption, smoke levels and exhaust emissions can be considerably reduced. In particular, the four-valve technology, coupled with mechanical low pressure and electronic high pressure fuel delivery systems set different requirements for inlet port performance. In the present paper four valve intake port design strategies are analysed for off highway engine using mechanical fuel injection systems.

Migration to BS6 emission norms from BS4 levels involves strenuous efforts involving advanced technology and higher cost. The challenging part is on achieving the stringent emission norms without compromising the engine fuel economy, performance and NVH factors. Selection of hardware and attaining an optimal behaviour is therefore vital. This article focuses on the evaluation of three different configuration of turbochargers for the same engine to meet the BS6 emission norms and performance. The turbocharger samples used measure the same compressor diameter with varying trim ratios. Simulation and testing of turbochargers ensured positive results for confirmation of the system. Parameters like low speed torque, smoke and compressor efficiency were evaluated and analysed for all configurations. The safe limits of surge and choke regions of all the compressors were also studied and verified.

Rising energy demands, ecological deterioration and diminution of fossil fuels has necessitated the researchers to search for alternatives. With alternate fuels like Liquefied Petroleum Gas (LPG), hydrogen and alcohol based fuels, it is easier to substitute with the present engine without many alterations. Excellent chemical properties of these fuels make them favorable for lean burn operation which makes it a cost effective option to achieve goals of better fuel economy and controlled emissions. In this regard, experimental studies were carried out to examine the effects of LPG with different proportions of alcohols like ethanol and methanol (5, 10 and 20%) on the performance, emission and combustion characteristics of a single cylinder SI engine operated at a constant speed of 1500 rpm with a optimized compression ratio of 10.5:1 under full throttle opening conditions at varying equivalence ratio.

The legislations on emission reduction is getting stringent everywhere in the world. India is following the same trend, with Government of India (GOI) declaring the nationwide implementation of BS 6 legislation by April 2020 and Real Driving Emission (RDE) Cycle relevant legislation by 2023. Additionally GOI is focusing on reduction of CO2 emissions by introduction of stringent fleet CO2 targets through CAFE regulation, making it mandatory for vehicle manufacturers to simultaneously work on gaseous emissions and CO2 emissions. Simultaneous NOx emission reduction and CO2 reduction measures are divergent in nature, but with a 48 V Diesel hybrid, this goal can be achieved. The study presented here involves arriving at the right future hybrid-powertrain layout for a Sports Utility Vehicle (SUV) in the Indian scenario to meet the future BS 6 and CAFÉ legislations. Diesel engines dominate the current LCV and SUV segments in India and the same trend can be expected to continue in future.

With introduction of Bharat Stage VI (BS VI) norms from 1st April 2020, automotive industry will observe one of most stringent Indian emission regulation implementation in line with International standards. The Bharat Stage VI (BS VI) regulation also mandates for Real Driving Emission (RDE) measurement from 1st April 2020 for data collection and subsequently establishment of RDE compliance Factor (CF) by 1st April 2023. Indian RDE test procedure will be largely based on European RDE with minor changes in terms of climatic conditions, traffic pattern, speed limit, topography, and vehicle population. For performing a successful RDE trial one of the most critical part is selection of a route on which all RDE boundary conditions can be met. This technical paper summarizes the outcome of RDE experiments carried out on Light Duty Vehicles (LDV) in the city of Pune, Mumbai, and Bangalore. The collected data was post processed using CO2 based Moving Average Window (MAW) method.

The Bharat Stage (CEV/Tractor) IV & V emission legislations will come into force in Oct 2020 & Apr 2024 respectively, posing a major engineering challenge in terms of system complexity, reliability, costs and development time. Solutions for the EU Stage-V NRMM legislation in Europe, from which the BS-V limits are derived, have been developed and are ready for implementation. To a certain extent these European solutions can be transferred to the Indian market. However, certain market-specific challenges are yet to be defined and addressed. In addition, a challenging timeline has to be considered for application of advanced technologies and processes during the product development. In this presentation, the emission roadmap will be introduced in the beginning, followed by a discussion of potential technology solutions on the engine itself as well as on the after treatment components.

Diesel engine pollutants include Oxides of Nitrogen (NOx) and Particulate Matter (PM) which are traditionally known for their trade-off characteristics. It’s been a challenge to reduce both pollutants at the source simultaneously, except by efforts through low temperature combustion concepts. NOx formation is dependent on the combustion temperature and thus the in-cylinder reduction of NOx formation remains of utmost importance. In this regard, water injection into the intake of a heavy-duty diesel engine to reduce peak combustion temperature and thereby reducing NOx is found to be a promising technology. Current work involves the use of 1-D thermodynamic simulation using AVL BOOST for modeling the engine performance with water injection. Mixing Controlled Combustion (MCC) model was used which can model the emissions. Initially, the model validation without the water injector was carried out with experimental data.