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Automotive manufacturers are concerned about the safety of its customers. Safety critical components like wheel hub are designed considering the severe loads generated from various customer usage patterns. Accelerated tests, which are derived from Real World Usage Patterns (RWUP), are conducted at vehicle level to ensure the wheel hub meet the durability targets. Load and strain measurement are done to understand the critical lateral loading undergone by the wheel hub. Measured data is synthesized to drive the duty cycle. Finite Element (FE) Analysis of Wheel end is performed at module level considering measured loads to capture the exact load path in physical test. Simulation results are compared with the measured strain for validating the FE analysis procedure. FE analysis was repeated for different wheel hub designs, combinations of different flange radius (R) and flange width (t), to understand the effect of the two critical dimensions on wheel hub durability.

For Automatic transmission application, crankshaft torque is transferred to torque converter through flex plate. As the flex plate has no functional requirement of storing energy as in case of Manual Transmission (MT) flywheel, flex plate design can be optimized to great extent. Flex plate structure must have compliance to allow the axial deformation of torque convertor due to ballooning pressure generated inside the converter. Flex plate experiences dynamic torque and centrifugal forces due to high rotational speed. It should have compliance to accommodate the assembly misalignments with torque convertor in both axial and radial directions. In this paper, sequential and hybrid optimization techniques are described to optimize the flex plate design with stress, stiffness and mass as design constraints. The load path, corrugation length and axial stiffness of flex plate captured accurately using this hybrid optimization.

Precise control over mixture formation withhigh fuel pressure and multiple injections allows Gasoline Direct Injection (GDI) engines to be operated satisfactorily at extreme conditions wherePort Fuel Injection (PFI) engines wouldnormally struggle due to combustion instability issues. Catalyst heating phase is one such important condition which is initiated after a cold engine start to improve the effectiveness of the three-way catalyst (TWC). For a given TWC specification, fast light-offof TWC is achieved in the catalyst heating phase by increasing the exhaust gas temperature with higher exhaust mass flow. The duration of this phase must be as short as possible, as it is a trade-off between achieving sufficient TWC light off performance and fuel efficiency.

Synchronizers are the most critical parts of a manual transmission. There are classical calculations available for the synchronizer design and studies are available for the normal functioning of synchronizer rings which describes how the synchronizer behaves in the event of gear shifting. The objective of this study is to describe the synchronizer behavior when synchronizers are not functional, i.e., in other gear engaged condition and the rings are free. This study describes the failure mechanism of the unused synchronizer rings which are moving freely in the packaging space. The findings of this synchronizer design cannot be limited only for synchronizer performance and standard durability calculations. To ensure proper function of synchronizer rings and to achieve the required life the external parameters like clearances, lubrication, clutch design for dampening torsional vibration from the engine are to be considered.

The global automotive industry is growing rapidly in recent years and the market competition has increased drastically. The engines with high torque delivery and deeper transmission ratios has become more and more common for a pleasant drivability experience. In a market highly driven from a comfort and an economic point of view, it is essential to develop a transmission and its components in an optimal way. One of the Unique Selling Point (USP) of a vehicle is the gear shift quality & it is highly important to have an optimum shift quality for an enhanced customer experience. Synchronizer plays a vital role for gear shifting performance in manual gearbox without any shifting assistance. The primary function of a synchronizer is to reduce the RPM difference between two gears before gear shifting with minimum time.

Synchronizer is the key element for the smoother gear shift operation in the constant mesh transmission. In the gear shift operation, the double bump occurs at the contact between the sleeve teeth and the clutch body ring teeth after the full synchronization. The double bump is random in nature and the dynamics is difficult to predict. The double bump gives a reaction force to the driver and affects the gear shift quality. This paper focus on the sensitivity analysis of the synchronizer ring index percentage and the clutch body ring asymmetric chamfer angle to reduce the occurrence and magnitude of the double bump. The system level simulation model is developed using 1D simulation tool. The modeling is done after complete declutching event so that there is no power supply to the transmission. The model can handle both upstream and downstream reflected inertia depending upon the gear shift event.

Material selection is based on Process such as forging, die-casting, machining, welding and injection moulding and application as type of load for Knife Edges and Pivots, to minimize Thermal Distortion, for Safe Pressure Vessels, Stiff, High Damping Materials, etc. In order for gears to achieve their intended performance, durability and reliability, the selection of a suitable gear material is very important. High load capacity requires a tough, hard material that is difficult to machine; whereas high precision favors materials that are easy to machine and therefore have lower strength and hardness ratings. Gears are made of variety of materials depending on the requirement of the machine. They are made of plastic, steel, wood, cast iron, aluminum, brass, powdered metal, magnetic alloys and many others. The gear designer and user face a myriad of choices. The final selection should be based upon an understanding of material properties and application requirements.

In the recent past a lot of emphasis is given for the overall weight reduction of the sound package used in the vehicles. The paper presents a study of one of such materials used in the automotive market. The dash panel is a primary area for the engine noise transmission to the cabin. Hence the material selection of the dash inner acoustic insulation is critical. In the conventional method a barrier (EVA) and a decoupler (foam) is used. In the conventional design the surface weight of the barrier has to be substantially high for the dash insulation to perform effectively and hence adds to more weight. In the present application of light weight material also known as dual density absorbers and barrier is used for the dash acoustic insulator. The study reveals the good acoustic performance of the light weight dash mat in terms of passenger cabin noise reduction and improved sound quality along with weight reduction.

Aerodynamic simulation using commercial CFD (Computational Fluid Dynamics) codes is now an integral part of the vehicle design process. Aerodynamic prediction and vehicle development program runs in parallel. This requires a good agreement between experimental measurements and CFD prediction of aerodynamic behavior of a vehicle. The comparison between experimental and simulation results show differences, as it may not be possible to replicate effect of all the wind tunnel parameters in the simulation. This paper presents the details of aerodynamic simulation process of a Crossover and its validation with the experimental results available from the wind tunnel tests. The results are compared for different configurations such as- closing the grille openings, removing the rearview mirror, adding ski-rack and using different tyres. This study also includes the effect of different wind speeds and yaw angles on the coefficient of drag.

Continually increasing customer demands and legislative Requirements regarding fuel economy, emissions, Performance, drive ability and comfort need to be met by every OEM's developing vehicles worldwide. There is a serious pressure to reduce CO2 emission from automotive application which contributes to around 15.9% of the total CO2 production based on the Surveys done time to time. In a developing market like India, many foreign players are entering with lots of option for offering to this market. The parameters of prime importance here are fuel efficiency with good drive ability and at the same time affordable price. Diesel engines are finding these benefits and attracting the buyer over its counterpart (Gasoline). The road condition and the driving pattern in India compared with developed countries differ to a major extent. In India, the Low speed uses are predominating in Cities and in Ghats.

Reducing the vibrations in the powertrain is one of the prime necessities in today's automobiles from NVH and strength perspectives. The necessity of 4×4 powertrain is increasing for better control on normal road and off-road vehicles. This leads to bulky powertrains. The vehicle speeds are increasing, that requires engines to run at higher speeds. Also to save on material costs and improve on fuel economy there is a need for optimizing the mass of the engine/vehicle. The reduced stiffness and higher speeds lead to increased noise and vibrations. One more challenge a powertrain design engineer has to face during design of its transmission housings is the bending / torsional mode vibrations of powertrain assembly. This aggravates other concerns such as shift lever vibrations, shift lever rattle, rise in in-cab noise, generation of boom noise at certain speeds, etc. Hence, reducing vibrations becomes an important and difficult aspect in design of an automobile.

This paper describes application of Design of Experiments (DOE) technique and optimization for mass reduction of a Sports utility vehicle (SUV) body in white (BIW). Thickness of the body panels is taken as design variable for the study. The BIW global torsion, bending and front end modes are key indicators of the stiffness and mass of the structure. By considering the global modes the structural strength of the vehicle also gets accounted, since the vehicle is subjected to bending and twisting moments during proving ground test. The DOE is setup in a virtual environment and the results for different configurations are obtained through simulations. The results obtained from the DOE exercise are used to check the sensitivity of the panels. The panels are selected for mass reduction based on the analysis of the results. This final configuration is further evaluated for determining the stiffness and strength of the BIW.

Plenum is the part located between the front windshield and the bonnet of an automobile . It is primarily used as an air inlet to the HVAC during fresh air mode operation. It’s secondary functions include water drainage, aesthetic cover to hide the gap between windshield to bonnet, concealing wiper motors and mechanisms etc. The plenum consists mainly two sub parts viz. upper plenum and lower plenum. Conventional plenum design which is found in majority of global OEMs employ a plastic upper plenum and a metal lower plenum which spans across the entire width of engine compartment. This conventional lower plenum is bulky, consumes more packaging space and has more weight. In this paper, we propose a novel design for the plenum lower to overcome above mentioned limitations of the conventional design. This novel design employs a dry and wet box concept for its working and is made up of complete plastic material.

The automotive industry is currently facing the challenge of significantly stringent requirements regarding CO₂ emission and fuel economy coming from both legislations and customer demand. Advanced engine technologies play a vital role for downsizing of gasoline engine. The development of key design technologies for high efficiency gasoline engines is required for the improvement of competitive power in the global automobile industry. This paper focused on effect of geometry of intake manifold of gas exchange process and consequently the performance of the engine. Specially, the optimal design technologies for the intake manifold and intake port shape must be established for high performance, increasingly stringent fuel economy and emission regulations. Space in vehicle or packaging constraints and cost are also important factors while consideration of the design.

This work discusses about the emission development of a 4 cylinder inline 3.3 liter CRDe to meet BS III emission norms applicable to 3.5 Ton and above category and upgradable to BS IV emission by suitable after treatment. This engine is developed from a 3.2l mechanical pump engine. During development the focus was on the usage of higher swept volume, selection of engine hardware like piston bowl, turbocharger, injectors and optimization of the injection parameters. A cost-effective solution for meeting the BS III norms in the LCV category without application of EGR and exhaust after treatment even though there is 15% increase of the power rating and 10% increase in Peak torque of the engine. Injection parameters like injection timing, injection quantity and pilot injection were optimized to meet the emission target.

In today's fast growing automobile world, the Emission limits are stringent; customer expectations of vehicle performance and Fuel economy are more. Achieving these parameters for the given engine are challenging task for any automobile engineers. BS4 Emission limits are 50% more stringent than BS3 limits and from April 2010 onwards, all passenger cars which will be selling in 13 metro cities in India should be BS4 emission compliant. In this paper, we have described how BS4 limits were achieved in a MPV with 2.49 l, 70kW Common Rail Direct Injection Turbocharged Diesel engine, with push rod. During Emission development, the following processes were followed to meet BS4 emission limits without sacrificing the engine performance, Fuel Economy and Noise. Selecting suitable hardwares like Turbocharger, EGR cooler at engine level to reduce NOx and Unburned Hydrocarbon Emissions with best Brake specific fuel consumption.

Validation of vehicle structure is at the core of reduction of product development time. Robust and accelerated validation becomes an important task. In service the vehicle is subjected to variable loads. These act upon the components that originate from road roughness, manoeuvres and powertrain loads. Majority of the body in white and chassis structural failures are caused due to vertical loading. Measured road load data in test track have variable amplitude histories. These histories often contain a large percentage of small amplitude cycles which are non damaging. This paper describes a systematic approach to derive the compressed load cycle from the measured road load data in order to produce representative and meaningful yet economical load cycle for fatigue simulation. In-house flow was developed to derive the compressed load time history.

In current competitive environment automobile industry is under heavy pressure to reduce time to market. First time right design is an important aspect to achieve the time and cost targets. CAE is a tool which helps designer to come up with first time right design. This also calls for high degree of confidence in CAE simulation results which can only be achieved by undertaking correlation exercises. In automobiles most of the structures are subjected to vibration from dynamic loads. All the dynamic road loads are random in nature and can be very easily expressed in terms of power spectral density functions. In the current scenario structural durability of the parts subjected to vibration is done partially through modal performance and partially though frequency response analysis. The only question that arises is what amplitude to use at what frequency and how to map all the accelerated tests dynamic load frequency spectrum to simulation domain.

October 2010 has brought major change over in Indian Auto Industries, with all India going BS-III Emission compliant (Metro with BS-IV Emission norms). During that time majority of the utility segment vehicles were having diesel engine with simple mechanical fuel injection system. To make these vehicles BS-III compliance cost effectively, with same fuel economy and reliability, was a challenging task. To enable this, Exhaust Gas Recirculation (EGR) through simple pneumatic EGR valve was the optimum technique. The EGR valve was controlled by means of simple Electronic Control Unit (ECU). Limitations of mechanical diesel fuel injection pump, stringent emission regulations, coupled with production constraints and variations, calls for robust control logics for governing EGR. The present work describes the robust strategies and logics of intelligent EGR governing of a 2.5 l, four Cylinder turbocharged, mechanical pump diesel engine for a BS-III compliant multi utility vehicle.

Regulations on pedestrian safety have been introduced globally since the year 1990 and in India it will have to be met around the year 2016. Process of making vehicle compliant to this regulation requires rigorous design development and testing. Testing involves propelling head-forms (Child and Adult) on bonnet at 35 km/h and 40 km/h and leg-forms (Upper and Lower) on bumper at 40 km/h according to the different National / International / NCAP regulatory requirements A pedestrian protection test rig has been indigenously designed and developed in-house to perform pedestrian protection impact testing in-house. The paper describes the salient features of the pedestrian protection test rig, its functioning, operation and process of acquiring the data for determination of the values required by crash safety regulations.