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This paper discusses the methodology setup for grill opening area prediction at the early development phase of the product development lifecycle, using a commercially available 1D simulation tool- AMESIM. Representative under hood has been modeled using Grill, Condenser, Radiator, intercooler, fan, and engine components. Vehicle velocity is used as an input to derive the airflow passing through the grill and other under-hood components based on ram air coefficient, pressure drop through different components (Grill, Heat exchanger, Fan & Engine). This airflow is used to predict the top tank temperature of the radiator. Derived airflow is correlated with airflow obtained from CFD simulation. A balance has been achieved between cooling drag & fan power consumption at different grill opening areas for target top tank temperature. Top tank temperature has been predicted at two different extreme engine heat rejection operating points.

In present study a comparative investigation and correlation attempted on small scale vehicle model for aerody-namic drag performance at small scale wind tunnel test facility in India vs full vehicle tested at globally know and accepted full scale test facility in Pininfarina, Italy. Current investigation aims to assess the small-scale wind tunnel suitable for testing 1:3 small scale car models A scale model of 1:3 scale size was tested in small scale wind tunnel (at IISC,Bengaluru, India) having test section area of 11.68 Sq. m. To understand the overall vehicle aerodynamic drag performance small scale model was test-ed for different configurations such as baseline, spoiler removal, underbody cover and different yaw condition. To understand the correlation between small scale vs full vehicle’s aerodynamic performance one actual vehicle was also tested at full scale wind tunnel Pinifarina Italy.

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.

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.

Nowadays, perception of automotive quality plays a crucial role in customer decision of vehicle purchase. Hence, automotive OEM’s are now working on the philosophy of “Quality Sound”. Out of all the Noise, Vibration & Harshness (NVH) issues identified in a vehicle, the ranking of Buzz, Squeak & Rattle (BSR) stands high and glove box rattle is one of the issues that is continuously observed in all customer verbatim. Specific issues like lid rattle and latch rattle are predominant and gets worse over mileage accumulation. Also minimizing BSR issues in glove box is difficult due to complex latch mechanism. While deciding the bump stop specifications more weightage is given to efforts. The bump stop is selected in a way as not to increase the glove box opening and closing efforts, but the selected bump stops will not provide enough preload to glove box lid leading to rattle issues.

With an increasing demand to reduce the product development time cycle from concept-to-vehicle, weight saving effort and less prototype initiative, CAE evaluation technique in the vehicle durability development must allow the computer simulation to reproduce the actual driving condition over a proving ground. This paper describes the case study to predict the durability performance of full vehicle using vehicle FE parts in ADAMS model. The objective is to carry out full vehicle simulation in actual road load condition using reduced full vehicle FE model, condensed with the ADAMS model. The measured acceleration is applied to the vehicle FE model and dynamic loads converted to equivalent static loads. The FE model solved in MSC.Nastran® with number of static load subcases converted from the measured proving ground road data. It also verifies the validity of the evaluation methodologies by simulation-to-experiment comparisons.

The ever-increasing customer expectations put a lot of pressure on car manufacturers to constantly reduce the noise, vibration, and harshness (NVH) levels. This paper presents the holistic approach used to achieve best-in-class NVH levels in a modern high-power density 1.5 lit 4-cylinder diesel engine. In order to define the NVH targets for the engine, global benchmark engines were analysed with similar cubic capacity, power density, number of cylinders and charging system. Moreover, a benchmark diesel engine (considered as best-in-class in NVH) was measured in a semi-anechoic chamber to define the engine-level NVH targets of the new engine. The architecture selection and design of all the critical components were done giving due consideration to NVH behaviour while keeping a check on the weight and cost.

Original Equipment Manufacturers (OEMs) should innovate ways to delight customers by creating affordable products with improved drive experience and occupant comfort. Vehicle refinement is an important initiative that is often take-up by the project teams to ensure that the product meets the customer’s expectations. A few important aspects of vehicle refinement include improving the Noise Vibration Harshness (NVH), ride and handling performance pertaining to the Functional Image (FI) of the product. Optimizing the suspension design variables to meet both ride and handling performance is often challenging as improving the ride will have a deteriorating effect on handling and vice-versa. The present work involves Multi-Objective Design Optimization (MDO) of the suspension system of an automotive Sports Utility Vehicle (SUV) platform considering both ride and handling requirements, simultaneously.

The increasing demand for higher specific power and the need for weight reduction and decrease of emissions have become the driving factors of product development in the automotive market today. Substitution of high-density materials and more precise adjustment of material parameters help in significant weight decrease, but it is accompanied by undesirable cost increase and manufacturing complexity. One of the approaches to optimize the design is through the process of integration which involves integrating the functional elements of two or more components into one and achieving a reduction in weight and cost without impacting required performance. This paper explains a similar approach followed as a part of the Design and Development of 1.5 L, 3 Cylinder CRDI Diesel Engine for a new vehicle platform, developed for automotive passenger car application.

The stringent emission regulations demand highly complex after-treatment systems. The packaging and functional requirements of the after-treatment system demand very close coupling of the diesel oxidation catalyst (DOC) with the turbocharger outlet. The sealing effectiveness between the turbocharger and DOC is ensured by the V-band grooved clamp along with the suitable gasket. This V-band grooved clamp is widely used in diesel engines due to its ease of assembly and low cost. Since the V-band grooved clamp is subjected to a very high temperature, vibration, thermal shock, a robust and holistic validation is required to ensure the functional and safety requirements. Despite its wide range of applications, the testing and validation methodologies required to effectively validate the strength and other aspects of the clamp are not fully defined. In the present work, the authors discuss the various design validation methods involved during the development of the V-band grooved clamp.

The cabin cool down performance is influenced by heat load, AC system components and Air handling components. The air handling components are AC duct, vane and vent. Design of AC duct vane plays a crucial role in the airflow directivity in cabin which enhances the cabin cool down performance. Simulations are carried out by rotating the vanes manually and requires post process for every iteration. It leads to more time consuming and more number of simulations to achieve the target value. Research articles focusing on automation and optimization of vane articulation studies are scanty. Thus, the objective of this work is to execute the vane articulation study with less manual intervention. A parametric approach is developed by integrating ANSA and ANSYS FLUENT tools. With Direct Fit Morphing and DoE study approach from ANSA delivers the surface mesh model for the different vane angle configurations.

A typical powertrain mount design process starts with performing the system calculations to determine optimum mount parameters, viz. position, orientation and stiffness values to meet the desired NVH targets. Therefore, a 6 degrees of freedom lumped parameter system of powertrain and mounts is modelled in Matlab®. The approach is to decouple the torque roll axis mode from the remaining five rigid body modes so that the response to the torque pulses is predominantly ‘oscillations about Torque Roll Axis’. This is achieved by optimizing the above mount parameters within specified constraints so that ‘Rotation about the torque roll axis’ is one of the natural modes of vibration. The tool developed here uses ‘Particle Swarm Optimization(PSO) algorithm’ because of its ease of implementation and better convergence to the solution. The algorithm is programmed in TK solver®.

Range anxiety is one of the major factors to be dealt with for increasing penetration of EVs in current Automotive market. The major reasons for range anxiety for customers are sparse charging infrastructure availability, limited range of Electric vehicles and range uncertainty due to diverse real-world usage conditions. The uncertainty in real world range can be reduced by increasing the correlation between the testing condition during vehicle development and real-world customer usage condition. This paper illustrates a more accurate test methodology development to derive the real-world range in electric vehicles with experimental validation and system level analysis. A test matrix is developed considering several variables influencing vehicle range like different routes, drive modes, Regeneration levels, customer drive behavior, time of drive, locations, ambient conditions etc.

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.

The cylinder block for the power train has always been a classic example of concurrent engineering in which disciplines like NVH, Durability, thermal management and lubrication system layout contribute interactively for concept design. Since the concept design is based on engineering judgment and is an estimated design, the design iterations for optimization are inevitable. This paper aims at outlining a systematic approach for design of crankcase for fatigue which would eliminate design iterations for durability. This allows a larger scope for design improvement at the concept stage as the design specifications are not matured at this stage. A process of stress optimization is adopted which gives accurate dimensional input to design. The approach is illustrated with a case study where an existing crankcase was optimized for fatigue and significant weight reduction was achieved.

Within the last decade, due to increasing fuel prices, unstable political situation in major oil producing nations and global warming, there is an increased demand for fuel efficient and environment friendly vehicles. In this context, research is being concentrated in the field of advanced, greener powertrain configurations ranging from hybrids to EVs to fuel cells to HCCI engines. The efficacy for any of the above stated powertrain technology, lies in the optimum component specification. Component specification, operational reliability, & life prediction are highly dependent on the traffic condition, driving nature and vary from country to country. For developing countries, like India, where the traffic & drive pattern are dense & slow moving, there is a dire need for generating load cycle based on Real World Usage Profile (RWUP). The paper will propose a systematic approach to create load cycles in order to derive component specifications for the powertrain based on RWUP.

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.

Automated manual transmission (AMT) is often preferred by car manufacturers as entry-level automation technology. The AMT technology can provide the comfort of an automatic gearbox at a reasonable cost impact over manual transmission (MT). This paper explains the unique approach to define the gear-shift map of a compact sports utility vehicle (SUV) considering the unique requirements of the Indian market. The real-world measurements revealed that an aggressive shift pattern with delayed upshifts and quick downshifts can deliver good low-end drivability and performance while compromising on fuel economy (FE). Moreover, the chassis dyno measurements in the modified Indian drive cycle (MIDC) indicated lower FE values. On the other hand, a shift pattern with early upshifts and delayed downshifts could help in achieving a better FE while compromising on drivability and performance. Hence, a unique approach is used to derive the most optimal gear-shift map for each operating gear.

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.

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, DMFs are widely used in high power-density diesel and gasoline engines. However, the real-world usage conditions pose a lot of challenges to the structural robustness of the DMF. In the present work, a new methodology is developed to evaluate the robustness of a DMF fitted in a compact sports utility vehicle (SUV) with rear-wheel drive architecture. The abuse conditions (mis-gear, sudden braking, etc) in the real-world usage could lead to a sudden engine stall leading to an abnormally high angular deceleration of the driveline components. The higher rate of deceleration coupled with the higher rotational moment of inertia of the systems might end up in introducing a significantly high impact torque on the DMF.