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Hydrogen is considered as one of the potential alternate fuel and when compared to other alternate fuels like CNG, LPG, Ethanol etc., it has unique properties due to absence of carbon. In the current work, Hydrogen engine of 2.5 L, four cylinder, spark ignited Turbocharged-Intercooled engine is developed for Mini Bus application. Multi-point fuel injection system is used for injecting the hydrogen in the intake manifold. Initially, boost simulation is performed to select the optimum compression ratio and turbocharger. The literature review has shown that in-order to get the minimum NOx emissions Hydrogen engines must be operated between equivalence ratios ranging from 0.5 to 0.6. In the present study, full throttle performance is conducted mainly with the above equivalence ratio range with minimum advance for Maximum Brake Torque (MBT) ignition timing. At each operating point, the performance, emissions and combustion parameters are recorded and analyzed in detail.

With the increase in the number of automobiles on road, there is a very strong emphasis on reducing the air pollution which led to evolution of stringent emission norms. To meet these stringent emission norms, the ideal solution is to optimize the engine hardware and the combustion system to reduce the emission at source thereby reducing the dependency on exhaust after treatment system. Gasoline Direct Injection (GDI) engines are gaining popularity worldwide as they provide a balance between fun to drive and fuel efficiency. Controlling the particle emissions especially Particle Number (PN) is a challenge in GDI engines due to the nature of its combustion system. In this study, experiments were performed on a 1.2Litre 3-cylinder 250bar GDI engine to capture the effect of injection strategies on PN.

Vehicle handing and ride are the critical attributes for customers while buying new passenger vehicle. Hence it is very important to design suspension which meets customer expectations. Often tuning of suspension parameters is very difficult at later stage like wheelbase, vehicle center of Gravity and other suspension parameters like roll center heights etc. A parametric mathematical model is built to study the effect of these parameters of vehicle handling and ride attributes at concept stage. These models are used to calculate the suspension ride rates, spring rates and Anti roll bar diameters for meeting target vehicle ride and handling performance. The model also calculates natural frequency of suspension and vehicle for understanding pitch and roll behaviours.

The automobile industry strives to develop high-quality vehicles quickly that fulfill the buyer’s needs and stand out within the competition. Full utilization of simulation and Computer-Aided Engineering (CAE) tools can empower quick assessment of different vehicle concepts and setups without building physical models. Vehicle execution assessment is critical in the vehicle development process, requiring exact vehicle steering system models. The effect of steering system stiffness is vital for vehicle handling, stability, and steering performance studies. The overall steering stiffness is usually not modeled accurately. Usually, torsion bar stiffness alone is considered in the modeling. The modeling of overall steering stiffness along with torsion bar stiffness is studied in this paper. Another major contributing factor to steering performance is steering friction. The steering friction is also often not considered properly.

In the conceptualization phase of vehicle development, for achieving reasonable dynamics performance, proper selection of steering system meeting all the requirements is necessary. This requires accurate prediction of major steering performance attributes like steering effort, steering torque, Turning Circle Diameter (TCD), %Ackerman and steering returnability. However, currently available models majorly depend on Computer Aided Engineering (CAE)-analysis or physical trials which requires system detailing and the same cannot be used for early prediction of the steering performances in the concept phase. This paper aims to address this deficiency with the help of a new steering performance calculator. In the calculator, performance attributes namely steering effort, steering torque, TCD and %-Ackerman has been modelled with engineering calculations and other attributes namely steering returnability&precision has been modelled through machine learning techniques.

The present work is focussed on the real-world challenges of a dual mass flywheel (DMF) equipped vehicle in the Indian market. DMFs are widely used to isolate the drivetrain from the high torsional vibrations induced by the engine. While DMFs can significantly improve noise, vibration and harshness (NVH) characteristics of a vehicle, there are multiple challenges experienced in real-world operating conditions when compared with the single mass flywheel (SMF). The present work explains the challenges of using a DMF in a high power-density diesel powertrain for a multi-purpose vehicle (MPV) application in the Indian market. Measurements on the flat-road operating conditions revealed that the DMF vehicle is very sensitive for launch behaviour and requires a higher clutch modulation. Vibration measurements at the driver’s seat confirm that the SMF vehicle could be launched more comfortably at the engine idle speed of 850 RPM.

During the cold start conditions engine must overcome higher friction loss, at the cost of fuel penalty till the optimum temperatures are reached in coolant and lubrication circuits. The lower thermal capacity of the lubrication oil (with respect to the coolant) inverses the relation of viscosity with temperature, improves engine thermal efficiency benefit. Engine oil takes full NEDC test cycle duration to reach 90°C. This leads to higher friction loss throughout the test cycle, contributing a significant increase in fuel consumption. Increasing oil temperature reduces viscosity, thereby reducing the engine friction. This helps to identify the focus for thermal management in the direction of speeding up the temperature rise during a cold engine starting. This work aims at the study and experiment of an exhaust recovery mechanism to improve the NEDC fuel economy.

Till recently supercharging was the most accepted technique for boost solution in gasoline engines. Recent advents in turbochargers introduced turbocharging technology into gasoline engines. Turbocharging of gasoline engines has helped in powertrains with higher power density and less overall weight. Along with the advantages in performance, new challenges arise, both in terms of thermal management as well as overall acoustic performance of powertrains. The study focuses mainly on NVH aspects of turbocharging of gasoline engines. Compressor surge is a most common phenomenon in turbochargers. As the operating point on the compressor map moves closer to the surge line, the compressor starts to generate noise. The amplitude and frequency of the noise depends on the proximity of the operating point to the surge line. The severity of noise can be reduced by selecting a turbocharger with enough compressor surge margin.

With the increasing need to have faster product development and yet achieve the optimum design, thrust on accurate FEA of components and system is felt. The connecting rod is an important component of the crank train and it has a significant mass contribution in multi-cylinder engine. Principal focus is directed to connecting rods having load ratio greater than or equal to 2. As the connecting rod operates in elastic range (i.e. high cycle fatigue life region) stress life approach is adopted for fatigue life evaluation. The three fold purpose of this paper is to establish an accurate FE modelling technique and analysis procedure that simulates the test conditions, aids in accurate fatigue life prediction and most importantly provides a simple procedure for virtual validation of connecting rod. To achieve this objective static strain measurement and fatigue test of connecting rod is carried out on a test bench.

High speed diesel engines are difficult to start in cold conditions (at subzero temperature) because the cylinder head and cylinder block absorbs heat of compression and thus preventing ignition due to the high surface to volume ratio. Also the coolant and the engine oil become viscous at subzero temperature and make the condition unfavorable for starting. Combustion optimization along with the help of a heating aid can make these engines to start quickly without any engine misbehavior. Cold startability is the ability of an engine to start within a specified time and continue to run without any malfunctioning. Combustion instability will lead to the misfiring of the engine unless it is calibrated properly. The European countries are subjected to a minimum temperature of -20°C to -25°C. So the intention of this work is to optimize the cold startability of Mahindra's Multi-Purpose Vehicle (MPV) up to -25°C which is to be sold in European countries.

This paper details the methodology used to show the importance of Low rolling resistance tires in Electric Vehicles. Fuel efficiency and range is paramount with most of the electric vehicle buyers. Although many people are now becoming aware of low rolling resistance tires but its development started way back in 1990’s. It is always challenging to achieve low rolling resistance in smaller tires of size 12 inch or 13 inch along meeting the other critical vehicle parameters such as ride and handling, NVH, durability and many more. The reduction in rolling resistance can also affect the traction properties of tires. In case of very low rolling resistance tires the traction will be very less but it can badly affect the other vehicle parameters. Selection of tires further depend upon the RWUP (Real World Usage Profile). It means the vehicle is targeted for which region and what is the condition of roads there.

Turbocharged common rail direct injection engines offer multiple benefits compared to their naturally aspirated counterparts by allowing for a significant increase in the power and torque output, while simultaneously improving the specific fuel consumption and smoke. They also make it possible for the engine to operate at a leaner air/fuel mixture ratio, thereby reducing particulate matter emission and permitting higher EGR flow rates. In the present work, a two cylinder, naturally aspirated common rail injected engine for use on a load carrier platform has been fitted with a turbocharger for improving the power and torque output, so that the engine can be used in a vehicle with a higher kerb weight. The basic architecture and hardware remain unchanged between the naturally aspirated and turbocharged versions. A fixed geometry, waste gated turbocharger with intercooling is used.

This report describes work performed jointly by Mahindra & Mahindra and IIT Delhi, including both simulations and single-cylinder engine development for three wheeler application, to quantify the effects of various parameters on the performance and NOx emission of an internal combustion engine fuelled by hydrogen. AVL Boost software was used to simulate the experimental conditions, by using Vibe 2-Zone combustion and Woschni heat models, together with kinetic equations for emission calculations. Developed AVL Boost Model was validated against the test result from a modified single cylinder CNG engine for three wheeler application fuelled with Hydrogen by comparing the performance and NOx emission at the same operating conditions. A good agreement was obtained between the results of the Boost Model and Experimental results.

The Micro-hybrid technology otherwise called as stop start system offers a significant improvement in fuel economy particularly in urban driving conditions, where more often the engine idles unnecessarily at traffic signals/jams. Micro-hybrid technology stops the engine at traffic signals/jams and starts the engine automatically on clearance of traffic signals/jams leading to reduced fuel consumption and emissions. This is achieved by monitoring several vehicle and engine parameters through appropriate sensing elements. In this study, the system architecture and functional definitions of start/stop system is defined. Equivalence class, boundary value and decision-table testing are used to generate test cases. On generation of test cases, their relevance on on-road robustness and scope for optimization towards time/efforts are analyzed. In the process, a matrix of different conditions and criteria are formulated. Under these conditions, the system behavior is evaluated.

Brake groan noise is resolved without any major change in the design of brake system and vehicle sub-system components in the development phase of a utility vehicle. The groan noise is observed during the end of the stopping of the vehicle under moderate braking. The concerned NVH issue is perceived as unacceptable noise in the passenger compartment. Groan induced vibration is subjectively felt on steering and seat frame. A typical process is established to successfully reproduce the groan which helped in precisely evaluating the effect of modifications proposed. The temperature range of the disc which has the highest probability to produce the groan noise is found out experimentally. The transfer path analysis is carried out to find the path contributions from suspension. Acoustic transfer functions from considered paths are measured with the suspension removed from vehicle.

With recent advancements to create light weight engines and therefore, to design stronger and lighter connecting rods, automobile manufacturers have looked upon vanadium micro-alloyed steels as the material of choice. These materials have been developed keeping in mind the strength and manufacturing requirements of a connecting rod. Since, 36MnVS4 has been the most popular of this category, the same has been discussed in this paper. The transition of manufacturers from the traditional C70S6 grade to the new 36MnVS4 must be dealt with in-depth study and modification of processes to adapt to new properties of the latter. C70S6 is a high carbon grade with superior fracture split whereas 36MnVS4 is a medium carbon grade with superior strength and ductility owing to the presence of vanadium.

In today’s scenario, internal combustion engines have conflicting requirements of high power density and best in class weight. High power density leads to higher loads on engine components and calls for a material addition to meet the durability targets. Lightweight design not only helps to improve fuel economy but also reduces the overall cost of the engine. Material change from cast iron to aluminium has a huge potential for weight reduction as aluminium has 62% lesser mass density. But this light-weighting impacts the stiffness of the parts as elastic modulus drops by around 50%. Hence, this calls for revisiting the design and usage of optimization tools for load-bearing members on the engine to arrive at optimized sections and ribbing profiles. This paper discusses the optimization approach for one of the engine components i.e., the FEAD (front end accessory drive) bracket.

Dual mass flywheel (DMF) is an excellent solution to improve the noise, vibration, and harshness (NVH) characteristic of any vehicle by isolating the driveline from the engine torsional vibrations. For the same reason, DMF’s are widely used in high power-density diesel and gasoline engines. However, the real-world usage conditions pose a lot of challenges to the robustness of the DMF. In the present work, by capturing the Real-World Usage Profile (RWUP) conditions, a new methodology is developed to evaluate the robustness of a DMF fitted in a Sports utility vehicle (SUV). Ventilation holes are provided on clutch housing to improve convective heat transfer. Improvement in convective heat transfer will increase the life and will reduce clutch burning concerns. Cities like Mumbai, Chennai, Bangalore, roads will have clogged waters during rainy season. When the vehicle was driven in such roads, water enters inside the clutch housing through ventilation holes.

The clutch pedal in manual transmission plays a significant role in defining the comfort of driver as the component is one of the end user’s direct interface in the vehicle. Whenever driver operates the clutch pedal, comfort and NVH refinement should be felt over the complete pedal travel. The expectations of customer on NVH refinements, such as pedal vibration felt on foot during actuation, becomes the part of perceived quality and hence addressing the concern is very crucial. Due to advancements of technology and down-sizing of engines, NVH becomes the challenging area where the clutch pedal vibrations need to be eliminated to improve the comfort. In this paper we are explaining the problem statement and NVH solution to eliminate the clutch pedal vibration observed during clutch pedal actuation. Pedal vibrations were very severe at 10% clutch pedal pressed condition, and the same tends to diminish till 50% clutch pedal pressed condition.

Aerodynamics of on-road vehicles has come to the limelight in the recent years. Better aerodynamic design of vehicle would improve vehicle fuel efficiency with increased acceleration performance. To obtain best aerodynamic body, the series of design modifications and different testing methodologies must be involved in vehicle design and validation phase. Wind tunnel aerodynamic force measurement, road load determination and computational fluid dynamics were the common methods used to evaluate the aerodynamic behavior of the vehicle body. As a novel approach, the present work discusses about the on-road (Real time) testing methodology that is aimed to evaluate the aerodynamic performance of vehicle body using surface pressure mapping. A 64-Channel digital pressure scanner has been utilized in this work for mapping the pressure at different locations of the typical vehicle body.