Search Results

Ride is considered to be one of the crucial criterion for evaluating the performance of a vehicle. Automobile industry is striving for improvement in designs to provide superior passenger comfort in Commercial vehicles segment. In Industry, Quarter-car model has been used for years to study the vehicle’s ride dynamics. But due to lower DOF involved in quarter car, the output accuracy is somewhat compromised. This paper aims in development of a 7 DOF full-car Model to perform the ride- comfort analysis for Light Duty 4*2 Commercial Bus using MATLAB Simulink which can be used to tune the suspension design to meet the required ride-comfort criteria. Firstly, experimental data and Physical Parameters are collected by performing Practical Test on commercial Bus on different road profiles. Secondly, a Full Car Mathematical Model with 7 DOF has been developed for a bus using MATLAB Simulink R2018a.

Euro 6 emission norms are getting implemented in India from April 2020 and it is being viewed as one of the greatest challenges ever faced by the Indian automotive industry. In order to achieve such stringent emission norms along with top performance for vehicle, a good strategy should be incorporated to control system out NOx emissions and soot regeneration. Extruded Vanadium catalyst is deployed for this passive regeneration system with DOC (Diesel Oxidation Catalyst), DPF (Diesel Particulate Filter) and SCR (Selective Catalyst Reduction), where the amount of catalyst loading in DOC plays an apex role in deciding conversion efficiency of SCR and passive regeneration capabilities. This study mainly focuses on the impact of catalyst loading of DOC over SCR efficiency. NO2 to NOx ratio should be close to 0.5 for optimum conversion efficiency of SCR. Catalyst loading in DOC decides the amount of NO2 coming upstream to SCR.

With implementation of stringent BSVI emission norms and regulations like OBD-II on vehicle, it is essential to define the life of exhaust after treatment along with the vehicle. Diesel after treatment generally consists of DOC, DPF and SCR. Lubricating oil contains phosphorus and zinc which adversely affect the DOC. Unburned hydrocarbons (UNHBC) and SOF in tail pipe get accumulated in the DPF. This requires regeneration process where in, high temperatures in exhaust after treatment (EATS) burn the adsorbed Sulphur or phosphorus, thereby improving the conversion efficiencies. Repeated regenerations lead to ash accumulation in DPF and this reduces its capability for soot accumulation. Sulphur in the exhaust impacts SCR through NOx conversion. The present study analyzes the effect of (1) Chemical aging (2) Thermal aging on 3.77 liter diesel engine after treatment. A test cycle was prepared to run the durability for EATS.

The diesel oxidation catalyst (DOC) is one of the major components of a diesel after treatment system. Earlier, DOCs were majorly used to oxidise un-burnt HC and CO from the exhaust gas to keep these pollutants within legislation limits. As legislative norms evolved towards becoming more stringent, the technology and chemistry of after-treatment catalysts have also advanced simultaneously. For Diesel Engines to meet BSVI emission norm, the DOC has a vital role to play. Apart from oxidizing un-burnt THC and CO, now it has to perform additional functions of converting NOx to NO2 to achieve desired NO2/NOx ratio for better DeNOx in the SCR and also give efficient exotherm across it when the cat burner fuel is injected during DPF Regeneration with minimal HC slip. In this paper, two DOCs having different PGM loadings and volumes are evaluated for their exothermal efficiencies and corresponding THC slips.

The intensifying demand of cleaner fuelled vehicles considering current norms of BSIV and upcoming stringent norms of BSVI with low cost solutions has promoted the development of CNG and dual fuel vehicles. CNG vehicle is anticipated to discover its extensive use for environment fortification and effective deployment of energy capitals. Thus, CNG vehicles can be pretty effective in averting environment deterioration. CNG has low carbon to hydrogen ratio, this leads to very low CO2 emissions compared to gasoline and diesel vehicles. CNG engines have the potential of low NOx and particulate emissions. Natural gas vehicle development has been directed on the way to current use of direct injection and port injection with S.I. engines. Generally for low cost development, all OEMs prefer optimization of existing engines. Similarly for this project, a diesel engine was converted to S.I. engine for development of low emission CNG engine.

Diesel engines have always been popular for their low end torque and lugging abilities. With their higher thermal efficiencies through technical advancements, diesel engines are preferred powertrains in mass transportation of goods as well as people [14] [15]. A diesel engine always banks on excess air, which is subjected to higher compression ratios so as to achieve temperatures, enough to facilitate auto-ignition of diesel. With the advent of turbocharging and intercooling, the air availability is further enhanced, ensuring better combustion efficiency, lesser HC, CO and particulate matter (PM) emissions together with improved fuel efficiencies [2] [15]. Higher air availability also has its own shortcomings in the form of higher NOx (Nitrogen oxides) emissions. With stringent emission norms in place, reduction of NOx as well as PM, without sacrificing performance and fuel economy, is of utmost importance.

The air purifier industry has seen a growth in terms of demand and sales lately. All credit goes to massive Industrialization in developing countries such as India. The most harmful of the pollutants are PM 2.5 articulates and NOx Emissions. This leads to the new trend of customers become health and comfort conscious and willing to pay more for better and improved transportation. To satisfy these demands, COEM’s are developing more numbers of Air conditioning buses. Although the OEM’s are meeting this demand of quantity, the quality of air from air conditioner is still suffer. One of the main reasons for this poor air quality is because of the ineffectiveness of conventional air conditioner air filters to control particulate materials i.e. PM2.5, biological pollutants i.e. microbes, bacteria, viruses, and gaseous pollutants i.e. CO, CO2, SO2, NOX, O3 & VOCs in air. As per various researches, health problems associated with bus occupant compartment air quality appear more frequently.

This paper focuses on partial encapsulation technique for reducing air-borne noise from the rocker cover of a commercial vehicle diesel engine. Due to increasing awareness, customers demand for improvised NVH (Noise Vibration and Harshness) performance in modern day vehicles. Better NVH performance implies better comfort for passengers as well as vehicle operator. This further increases the driver up time due to reduced driver fatigue. In order to improve NVH performance of existing vehicle and observe different noise and vibration zones, detailed noise and vibration mapping was carried out on one of our vehicle platform. It is observed that engine noise is one of the major contributors for interior noise, apart from road inputs etc.

In order to stand apart from the competition, there is an ever growing demand in Indian commercial vehicle segments to reach higher fuel economy while achieving the emission goals set by the BS-VI norms. With emissions standard set by BS-VI, novel techniques to improve fuel efficiency have to be considered that have least impact with respect to NOx and soot emissions. The optimization of exhaust and intake valve lifts with respect to engine speed, technology commonly known as Variable Valve Lift and Timing (VVT/VVL), has been implemented in many passenger vehicles propelled by gasoline engine. The aim of this work is do initial assessment of utilizing the VVL method on a LMD commercial vehicle diesel engine. A 3.8 litre BS-VI turbocharged EGR engine is used for this study. Valve lift and timing optimization for better fuel efficiency at rated power engine speed is carried out by using one-dimensional thermodynamic simulation software AVL BOOST.

During the last few decades, concerns have grown on the negative effects that diesel particulate matter has on health. Because of this, particulate emissions were subjected to restrictions and various emission-reduction technologies were developed. It is ironic that some of these technologies led to reductions in the legislated total particulate mass while neglecting the number of particles. Focusing on the mass is not necessarily correct, because it might well be that not the mass but the number of particles and the characteristics of them (size, composition) have a higher impact on health. During the diesel engine combustion process, soot particles are produced which is very harmful for the atmosphere. Particulate matter is composed of much organic and inorganic composition which was analyzed after the optimization of SCR and EGR engine out.

Air Pollution is a major concern in our country due to which Indian Government has taken a decision to move from BS-IV to BS-VI which is nearly 90% reduction in NOx and 50% in particulate matter along with addition of particulate number regulation for BS-VI in comparison to BS-IV norms in very short span of time. Vehicle manufacturers are also having the challenge to produce low cost and fuel efficient product with BS-VI solution in order to meet tightening emission regulations and increasing needs of lower fuel consumption. Detailed study is done with different approaches to meet BS-VI emission which is elaborately explained in different aspect of engine design and after treatment parameter with its pros and cons. After Treatment selection plays an important role in engine development to meet stringent emission legislations and customer demands. Strategies for BS-VI were described with the advantage and drawbacks for after treatment selection.

The urea NOx selective catalytic reduction (SCR) is an effective technique for the reduction of NOx emitted from diesel engines. Urea spray quality has significant effect on NOx conversion efficiency. Air less injection is one of effective, less complex way of injecting urea spray into the Exhaust stream. Further with air less injection it become more challenging in an engine platform of ~3 to 4L where Exhaust mass flow and temperature are relatively less. The droplet diameter and velocity distribution of De-Nox system has taken as input along with Engine raw emission data for a numerical model. The atomization and evaporation of airless urea injection systems were modeled using computational fluid dynamics. The numerical model was validated by the experimental results.

Future emissions regulations like BSIV and above in India, Diesel engine manufacturers are forced to find complex ways to reduce exhaust gas pollutant emissions, in particular NOx and particulate matter (PM). Exhaust gas recirculation (EGR) into the engine intake is an established technology to reduce NOx emissions. The distribution of EGR in each cylinder plays vital role in combustion process and hence it will affect exhaust emissions. The influence of EGR mixture design and its effect on distribution across the cylinder has significant impact on the NOx-PM trade-off which is studied on light duty direct injection diesel engine. A simulation and experimental study of EGR mixer design is conducted to explain this effect and the distribution of EGR across the cylinder at different EGR flow rate.

Exhaust gas recirculation (EGR) is one of the most effective methods for reducing the emissions of nitrogen oxides (NOx) of diesel engines. EGR system has already been used to mass-produce diesel engines, in which EGR is used at the low and medium load of engine operating condition, resulting in NOx reduction. In order to meet future emission standards, EGR must be done over wider range of engine operation, and heavier EGR rate will be needed. It is especially important for EGR to be done in a high engine load range since the amount of NOx is larger than the other engine operation conditions. EGR systems adapted to the diesel engines of trucks usually recirculate exhaust gas utilizing the pressure difference between upstream part of the turbocharger turbine and downstream part of the compressor. The venturi throat diameter plays the vital role for the flow of EGR across the exhaust and intake.

Turbo lag is a very common phenomenon with all diesel engines using the turbo charger to boost power output from an engine. Naturally aspirated diesel engine which is more polluting, heavier, having higher power losses makes a diesel engine more lethargic. Turbocharged diesel engine is fuel efficient, having lower emissions and better power. A smaller sized turbocharged diesel engine delivers power equivalent to larger sized engine; Turbo Lag is the time required to change power output in response to throttle inputs. Turbo lag results in slow increase of speed when we press the accelerator pedal. Turbo lag becomes a real cause of concern when rapid changes in power are required. This is due to the time required for a turbocharger and exhaust system to generate the required boost.

Diesel engines are facing stringent norms and future survival with its lower availability is one of the biggest concerns for OEMs of heavy duty commercial vehicles. This is leading to uplifting of new, latent and innovative techniques to achieve these norms with best possible BSFC to reduce overall diesel consumption. The prime objective of this study is to identify and explore the latent strength of pre and post injection on engine performance, emissions and oil dilution due to soot. The post injection strategy has the potential to reduce soot with almost same NOx and fuel consumption depending on the delay of post injection and its quantity. It aids to increase the engine out temperatures for assistance of after-treatment devices, thus meeting higher temperature requirements for NOx and PM conversion for stringent norms of BSVI.

SCR being an advanced active emission technology system for diesel engine, is one of the most cost-effective and fuel-efficient technologies available for complying with the stringent NOx emission legislations. SCR catalyst volume is being considered as the most concerned part for NOx reduction and durability and a key element leading to high financial assessments. The SCR Optimization reduces the possibility of ammonia slip and leads to high NOx conversion rates. By improving the performance of the SCR, the optimization solution also reduces the amount of catalyst needed, thereby reducing associated costs. The decrease in SCR catalyst volume by 1m3 with respect to current set-up will lead to 15% reduction in the total cost of catalyst. All the factors affecting the SCR catalyst volume were focused in detail and the plausible range of catalyst volume was investigated by comparative measurement of these factors.

Crankshaft is one of the critical components of an engine (5C: cylinder head, connecting rod, crankshaft, camshaft and cylinder block). It is subjected to repetitive and dynamic loads due to cyclic operation of an engine, inertia forces due to uneven mass distribution with failure zones as fillets and holes in journal locations. Fatigue is most common cause in failure of the crankshaft. Its failure will cause serious damage to the engine so its reliability verification must be performed. The load is applied as per the firing order of the cylinder for 2 revolutions of crankshaft, to cover firing condition of each cylinder. Loads with respect to crank angle or time are applied at respective locations and results are taken on 360 steps for 2 complete revolutions of crank. The topic was chosen because of increasing interest in higher payloads, lower weight, higher efficiency and shorter load cycles in crankshaft equipment.

Air motion in a cylinder in a compression ignition engine affects on mixing of air-fuel, quality of combustion and emission produced. With upcoming stringent norms for diesel engines, it is necessary to enhance air-fuel mixing for proper combustion. Swirl and tumble are forms of air motion. Swirl is a rotational motion of a bulk mass within cylinder. Swirl is generated by shaping and countering intake manifold and valve ports. Swirl enhances air-fuel mixing and helps to spread flame-front during combustion. The objective of this paper is to analyze the impact of different swirl ratios on NOx and soot emission characteristics inside the cylinder of a DI Diesel engine. The effects of different geometrical parameters of helical port were studied and the swirl ratios are optimized by optimizing the geometrical parameter of helical port. This can be done by different manufacturing, polishing and grinding processes.

Direct injection compression ignition engines have proved to be the best option in light duty applications but rapid depleting sources of conventional fossil fuels, their rising prices and ever increasing environmental issues are the major concerns. Alternate fuels, particularly bio fuels are receiving increasing attention during the last few years. Biodiesel has already been commercialized in the transport sector. In the present work, a turbocharged, intercooled, DI diesel engine has been alternatively fuelled with biodiesel and its 20% blend with commercial diesel. The effect of biodiesel addition to diesel on engine performance, combustion, and emissions were studied in a turbocharged, high-pressure common rail diesel engine. Biodiesel/diesel blends with different biodiesel fractions were used and compared with neat biodiesel and diesel at different engine loads and speeds.