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In order to meet the challenges of future CAFE regulations & pollutant emission, vehicle fuel efficiency must be improved upon without compromising vehicle performance. Optimization of engine breathing & its impact on vehicle level fuel economy, performance needs balance between conflicting requirements of vehicle Fuel Economy, performance & drivability. In this study a Port Fuel Injection, naturally aspirated small passenger car gasoline engine was selected which was being used in a typical small passenger car. Simulation approach was used to investigate vehicle fuel economy and performance, where-in 1D CFD Engine model was used to investigate and optimize Valve train events (Intake and exhaust valve open and close timings) for best fuel economy. Engine Simulation software is physics based and uses a phenomenological approach 0-D turbulent combustion model to calculate engine performance parameters. Engine simulation model was calibrated within 95% accuracy of test data.

In the recent years world-wide automotive manufacturers are continuously working in the research of the suiTable technical solutions to meet upcoming stringent carbon dioxide (CO2) emission targets, defined by regulatory authorities across the world. Many technologies have been already developed, or are currently under study, to meet the legislated targets. To meet this objective, the generation of tumble at intake stroke and the conservation of turbulence intensity at the end of compression stroke inside the combustion chamber have a significant role in the contribution towards accelerating the burning rate, increasing the thermal efficiency and reducing the cyclic variability [1]. Tumble generation is mainly attained by intake port design, and conservation is achieved during the end of compression stroke 690 ~ 720 crank angles (CA) which is strictly affected by the piston bowl geometry and pentroof combustion chamber shape.

Recently, the Flexible Pedestrian Legform Impactor (or Flex-PLI) - an advancement over the existing EEVC legform - was included in the Global Technical Regulation for Pedestrian Safety viz. GTR-9. The legform tool undergoes impact testing with vehicle at 40kmph in order to evaluate the frontal structure of vehicle for Pedestrian Safety. Being more biofidelic design over the old EEVC legform, Flex-PLI is more flexible and sensitive towards different vehicle designs, shapes and inner bumper structure. This flexibility and sensitiveness of its design also calls for examining the Manufactured FlexPLI for its efficacy under impact testing in terms of its Durability, Repeatability and Reproducibility. This study aims at validating the performance of the test device by building a platform for computing the variations in test results. In this study, three key aspects are identified to measure the performance of this device - Durability, Repeatability, and Reproducibility.

In a Passive suspension, a shock absorber generates damping force by pressurizing the oil flow between chambers. Typically, vehicle responds with suspension deflection, which significantly depends on damping forces and suspension velocity. Tuning dampers for various roads and steering input is an iterative balancing process. In any setting, damping force w.r.t velocity is tuned for optimum ride and handling performance. Practically, to achieve a balance between the two is a tedious task as the choices & arrangements of inner parts like piston, port, valve etc., which defines the forces set up [soft / hard] are almost infinite. The objective of this paper is to measure, objectify and evaluate the performance of two such optimum setting in various ride and handling events. A passenger car set up with an optimum soft & hard suspension damping force is studied for various ride and handling sub-attributes and their conflicts are examined in detail from a performance point of view:

The most widely used type of windshield wiper system employs a coil spring for wiper arm pressure generation. This spring is fixed between the arm head (fixed part) and wiper arm (moving part) and the tension in the spring is responsible for pressure generation. The present arrangement although being unsophisticated design, has following drawbacks: Inability to change wiper arm pressure according to change in vehicle speed. Inability to provide constant arm pressure during the complete range of motion along varying curvature of windshield. Inability to reduce/remove the continuous pressure on wiper blade when vehicle is parked for long durations resulting in permanent deformation of wiper blade rubber. This paper describes how electromagnets can be used to overcome the above stated inherent limitations of the windshield wiper system. An electromagnet is a device which produces magnetic field on application of electric current.

Gearbox power transfer efficiency is a major factor in overall powertrain efficiency of a passenger vehicle. With rapidly changing emission and fuel efficiency regulations, there is a push to increase the gearbox efficiency to improve the overall fuel economy of the vehicle. In case of an existing gearbox, efficiency can be improved by using the low viscosity lubrication oil. Despite a benefit in increasing the gearbox efficiency, lowering down the viscosity of lubrication oil gives rise to few challenges with respect to its performance. One of these challenges is breather performance which defines that transmission oil should not come out of breather pipe in some pre-defined conditions during gearbox operation. As this validation is being carried out on proto parts when the complete system is ready, failure to satisfy the defined criteria for breather performance can lead to multiple trials.

Front suspension frame is an integral part of automobile chassis which acts as a major load carrying structural member and connects different suspension components with body. It provides the required stiffness for achieving desired vehicle dynamics performance. Acting as a major road load path from tire to body, it also acts as a mounting base for suspension arm, steering and compression rod. Considering the competitive market conditions, increased fuel efficiency demand along with enhanced structural durability, it is important to evaluate suspension frame for stiffness and durability using Computer Aided Engineering (CAE) methodology so as to reduce product development time and First Time Right cost effective design. In this paper focus is given on CAE methodology used to design a light weight tubular kind of suspension frame for light commercial vehicle with stiffness comparable to conventional sheet metal suspension frame and similar durability performance with reduced weight.

In today’s Indian automotive industry, vehicles are becoming more complex and require more efforts to develop. Also, new and upcoming regulations demand more trials under varied driving conditions to ensuring robustness of emission control. Combined with expectations of customer to get new products more frequently, requires solutions and methods that can allow more trials with required accuracy to ensure compliance to stricter regulation and delivery a quality product. This translates into more trials in less time during the development life cycle. Recently, to overcome above challenge, there has been focus on simulating the vehicles trials in engine bench environment. ‘Road to Lab to Math’ (RLM) is a methodology to reduce the effort of On-road testing and replace it with laboratory testing and mathematical models. Also, on-road testing of prototype vehicles is expensive as it requires physical parts.

Vehicle heat management has become a serious concern due to escalating under-hood and exhaust temperatures. Compact vehicle packaging caused by downsizing has further magnified this concern. In an automobile, fuel is stored in a metallic or plastic fuel tank. In addition to fuel storage, temperature inside fuel tank has to be maintained at a certain limit in order to control high fuel evaporation rate and prevent deterioration of parts. The fuel tank surface temperature is governed by heat rejection from the engine, exhaust system and heat radiated from the road. Generally, mechanical shielding has been found to be an efficient defense to the heat management problem. However ‘what to shield’, ‘where to place the shield’ and ‘how to shield’ are the major challenges. This paper describes a methodology followed to reduce temperature on fuel tank surface by varying material, geometry and layout of heat shields.

The fuel efficiency of a vehicle depends on multiple factors such as engine efficiency, type of fuel, aerodynamic drag, and tire friction and vehicle weight. Analysis of weight and functionality was done, to develop a lightweight and low-cost Roof rack rail. The Roof rack rail is made up of a lightweight material with thin cross section and has the design that allows the fitment of luggage carrier or luggage rack on the car roof. In starting this paper describes the design and weight contribution by standard Roof rack rail and its related parts. Secondly, the selection of material within different proposed options studied and a comparison of manufacturing and design-related factors. Thirdly, it has a description of the design of Roof rack rail to accommodate the luggage carrier fitment on the car roof. Moreover, optimizations of Roof rack rail design by continuous change in position, shape, and parts used.

Vehicle Hood being the face of a passenger car poses the challenge to meet the regulatory and aesthetic requirements. Urge to make a saleable product makes aesthetics a primary condition. This eventually makes the role of structure optimization much more important. Pedestrian protection- a recent development in the Indian automotive industry, known for dynamics of cost competitive cars, has posed the challenge to make passenger cars meeting the regulation at minimal cost. The paper demonstrates structure optimization of hood and design of peripheral parts for meeting pedestrian protection performance keeping the focus on low cost of ownership. The paper discusses development of an in-house methodology for meeting Headform compliance of a flagship model of Maruti Suzuki India Ltd., providing detailed analysis of the procedure followed from introduction stage of regulatory requirement in the project to final validation of the engineering intent.

Nowadays much greater emphasis is given on improving the NVH Performance of an automobile due to global move of customer satisfaction. Noise is an irritant to a valued customer - customer expects value for money in all perspective. There are many sources for noise generation in a vehicle. Noise due to pulsating fuel flow is one of the major causes. The pressure pulsation from the fuel supply system (generated by the sudden opening & closing of the injectors result in pulses inside rail, Low Pressure or High Pressure pump pulses, sudden cross section changes in flow path, etc) can cause an undesirable noise which may propagate as fluid or structure borne noise in to the cabin room, therefore in a conventional engine, a pulsation damper is usually mounted on the fuel rail to diminish the undesirable noise. However, the pulsation dampers are quite expensive. Therefore, several studies have focused on reducing fuel pressure pulsation by various methodologies.

With steep increase in fuel prices, there is a strong need for development of better engines with improved performance and emissions. This needs a dedicated effort on engine hardware optimization for lower CO2 levels. Exhaust muffler design is trade-off between noise, backpressure and size/weight. With increase in exhaust muffler volume and simplification of structure there is a corresponding drop observed in exhaust pressures. Study of such a phenomenon would give an insight to benefits achieved based on changes in muffler volumes/structure. This in a way leads to engine improvement. In this paper it has been shown how exhaust muffler characteristics (size and internal construction) impacts engine performance.

Offering the most fuel efficient cars to the customer is the biggest challenge for entire auto industry. Increasing engine efficiency and reducing the emissions with higher power is the best way to delight the customers. The demands for high power and better performance have resulted in progressive higher loading on internal components, and are putting challenge for the engine designers and analysts. It is required to discover and implement the most efficient analysis processes to ensure better durability, improved thermal performance and sealing ability of gasket in the main parts of engine during early design phase with keeping focus on development cost. This paper shows the integrated approach of CFD and structural analysis considering the thermal loading and higher cylinder pressures. The study focuses on the evaluation of Gasoline engine component durability and ensuring the gasket sealing during early design stage to reduce the prototyping cost and time.

Government’s focus on road safety requirements is resulting in faster adoption of stringent automobile safety regulations in India. In addition, due to changing customer preference, automobile companies are also working to provide safer vehicles in the market. Due to the complexity and high cost of the vehicle safety testing, more focus is given to development of CAE simulation technologies to validate the design for meeting regulatory norms, reducing design cycle time and number of physical tests. Safety requirement in vehicle safety regulations is to minimize the impact transfer to the occupants in case of vehicle crash. During vehicle crash condition, there is possibility that driver head may hit the gear shift lever assembly (GSLA) knob as it falls in the hitting area with respect to driver seat reference point (SRP). There is a regulatory requirement for the maximum acceleration level that is to be experienced by the driver during impact to prevent serious head injury.

With the increasing competition in the automotive industry, customer experience & satisfaction is at the top of every organization's goals. The customers have evolved & NVH refinement has become the parameter for their decision making in buying a car. The major source of rumble noise in a vehicle is the induced vibrations due to combustion forces in an IC engine. These vibrations are then transferred to the vehicle body through engine mounts. Hence engine mounts play a key role in defining the NVH & the ride performance of any vehicle. However, it is infeasible to validate every mount design through the physical test as it will be both costly & time-consuming. But multiple design iterations can be verified by the CAE approach quite effectively. This paper focuses on the novel CAE approach to evaluate the mount vibrations due to engine dynamics. The process involves preparing a FEA model of the complete Powertrain system.

Valve train system is one major contributor to engine overall friction loss and is approximately 30% of total engine friction at lower speed and approximately 20 % at higher engine speed. Valve spring loads (preload and working) are proportional to friction loss of valve train. To optimizing the valve spring design main requirement is valve train perform it function safely at maximum engine cutoff RPM with minimum preload and working load. Robustness and frictional power loss are contradicting requirement, robustness demand high stiffness spring for better valve jump and bounce performance with dynamic safe valve spring design, on the other hand low frictional power loss demand for use of low stiffness spring. To optimize the valve spring stiffness for meeting both the requirement we need accurate prediction of valve spring in design stage and good correlation with testing data to reduce the number of iterations.

Radiators are one of the major components in the automotive engine cooling system. The road excitations from the frame to the radiator are dampened using rubber bushes. In this work, we analyzed a radiator sub-assembly with bushes by applying acceleration which are recorded at the center of gravity of the radiator. The radiator is considered as the concentrated mass which is attached to the upper and the lower radiator tank which is further connected to the frame through the bushings. An implicit transient dynamic analysis is set up. The hyper elastic coefficients for EPDM rubber are determined using the experimental data fit and structural damping coefficients are applied. When excited by the acceleration applied at center of the radiator component, the rubber bushes are deformed severely. Moreover, the analysis shows high strains in certain location on the upper bush where the part showed actual failure in the testing.

With the advent of stricter regulation for tail pipe emission and urge to reduce the carbon foot prints, the engine hardware has undergone through evolutionary changes over the years i.e., boosting, low viscosity engine oil, high pressure fuel injection, cooled EGR, friction reduction, downsizing etc. These technological changes have led to the challenge of increase in radiated noise level from the engine (source) due to increased number of auxiliary drives on engine i.e., Turbo charger, HP fuel pump along with faster combustion & harsher operating conditions. The fuel system is one such system which has become most intricate with operating pressure going above 2000bar in the fuel rail and capability of up to 10 fuel injection per combustion. These changes in hardware could result in abnormal noise generation during specific operating conditions which may result in customer annoyance inside vehicle cabin.

In view of global concern for greenhouse gas emissions, need for greener and efficient Engines is increasing. Hence is it imperative that Internal Combustion Engines are improved in terms of efficiency to reduce Greenhouse gas emissions and meet CAFE targets. The cooling system of an ICE plays a major role in a vehicle performance. In this system, the radiator, thermostat, and cooling fan are the main components. Conventional cooling system uses Wax-type thermostat which is activated at specified coolant temperature and maintain same coolant temperature in fully warmed up condition at all engine operating points. Operative temperature selection in Wax-type is trade-off between engine friction & thermal efficiency at lower loads & knocking at higher loads. An electronic thermostat is a good alternative to maintain optimum temperature as per operating point requirement since optimum temperature at different operating points can be different.