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The present work discusses the developed simulation model aimed to predict the heat rejection (HR) performance and external pressure drop characteristics of automotive charge air cooler (CAC). Heat rejection and airside pressure drop characteristics of CAC were predicted for the conditions of different charge air mass flow rates and different cooling air velocities. The lack of detailed research on CAC performance prediction has motivated the development of the proposed simulation model. The present 1-D simulation has been developed based on the signal library of AMESIM application tool. Input parameters for this simulation such as core size, tube pitch, tube height, number of tubes, fin density, louver angle, louver pitch, charge air mass flow rate, cooling air velocity, charge air inlet temperature, and ambient temperature. Heat rejection curve and airside pressure drop of CAC were the output of the present simulation.

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.

Being a safety critical aggregate, every aspect of brake system is considered significant in vehicles operations. Along with optimum performance of brake system in terms of deceleration generation, brake pedal feel or brake feel is considered as one of the key elements while evaluating brake system of vehicles. There are many factors such as liner and drum condition, road surface, friction between linkages which impress the pedal feel. Out of these, in this paper we will be discussing the factors which influence the brake pedal feel in relation to the driver comfort and confidence building. Under optimum braking condition, brake operation must be completed with pedal effort not very less or not very high, brake pedal feel must be firm throughout the operation, in such a way that it will not create fatigue and at the same time it will give enough confidence to the driver while operating with acceptable travel.

Major focus was given on the Comfort, Fuel efficiency & Safety during the development of the passenger cars, which certainly drives the vehicle business of Original Equipment Manufacturer (OEM’s). The air Conditioning in a car, plays an important role in the area of comfort of the passengers and fuel efficiency point of view. Especially Heat Exchanger plays a pivotal role in the air conditioning system. So, it’s a challenge for the OEM’s to select and design the optimal heat exchanger from the supplier, which meets the performance and packaging requirements during the design phase of the product development cycle. The objective of this paper to focus on analytical calculation or framework was developed using an excel tool considering the effect of variable geometry of fin which includes louver pitch, louver angle and louver length in a multi-pass condenser. Further, this theoretical calculation was validated using experimental data and CFD simulation.

As the FTP-75 drive cycle does not have a prescribed gear shift pattern, automotive OEMs have the flexibility to design. Conventionally, gear shift pattern was formulated based on trial and error method, typically with 10 to 12 iterations on chassis dynamometer. It was a time consuming (i.e. ~ 3 to 4 months) and expensive process. This approach led to declaring poor fuel economy (FE). A simulation procedure was required to generate a gear shift pattern that gives optimal trade-off amongst conflicting objectives (FE, performance and emissions). As a result, a simulation tool was developed in MATLAB to generate an optimum gear shift pattern. Three different SUV/UV models were used as test vehicles in this study. Chassis dyno testing was conducted, and data was collected using the base and optimized gear shift patterns. Dyno test results with optimized gear shift pattern showed FE improvement of ~ 4 to 5% while retaining the NOx margin well above engineering targets.

There is a higher demand for quieter tractors in the agri-industry, as the continued exposure to noise levels have disastrous effects on operator’s health. To meet the world-wide regulatory norms and to be the global market leader, its mandatory to develop the comfortable tractor which meets homologation requirements and customer expectations. Typically, Operator Ear Level (OEL) noise has been evaluated in the test, after First Proto has been made. This approach increases cost associated with product development due to late changes of modifications and testing trails causing delay in time-to-market aspect. Hence, there is a need to develop the methodology for Predicting tractor OEL noise in virtual environment and propose changes at early stage of product development. At first, full vehicle comprising of skid, sheet metals and Intake-exhaust systems modelled has been built using Finite Element (FE) Preprocessor.

Fuel efficiency is critical aspect for commercial vehicles as fuel is major part of operational costs. To complicate scenario further, fuel efficiency testing, unlike in passenger cars is more time consuming and laborious. Thus, to save on development cost and save time in actual testing, simulations plays crucial role. Typically, actual vehicle speed and gear usage is captured using reference vehicle in desired route and used it for simulation of target vehicle. Limitation to this approach is captured duty cycle is specific to powertrain and driver behavior of reference vehicle. Any change in powertrain or vehicle resistance or driver of target vehicle will alter duty cycle and hence duty cycle of reference vehicle is no more valid for simulation assessment. This paper demonstrates approach which uses combination of tools to address this challenge. Simulation approach proposed here have three parts.

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.

Currently the Automotive industry demands highly competitive product to survive in the global tough competition. Even if there is a slight reduction in product cost and time has a high significant impact on business. Engineers are under tremendous pressure to develop competitive and give better product concern resolution at the earliest. To arrest the failure of this thermostat vent, an innovative approach was used to relocate de-aeration restrictor on the hose to the thermostat root. Thus, resolving the product concern by increasing the strength of the vent at root and providing good business impact on cost savings. Physical testing has provided an effective way to smoothen product development for concern resolution. This Paper highlights approach on an attempt to field failure simulation with existing and modified design with lab test results.

First time right vehicle performance and time to market, remains all automotive OEMs top priority, to remain competitive. NVH performance of product communicates impression to customer, remains one of the most important and complex attribute to meet, considering performances to be met for 20 Hz -6000 Hz. Frontloading techniques (FEM/BEM/SEA/MBD) for NVH are critical and necessary to achieve first time right NVH performance. Objective of this paper is to present a frontloading approach for automotive sound package optimization (absorber, barrier and damper elements) for SUV vehicle. Current process of designing sound package is mainly based on experience, competitive benchmarking of predecessor products. This process (current process) heavily depend on testing and validation at physical prototype and happens at later stages of program, especially on tooled up body.

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.

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.

It is imperative that all automobile manufacturers conduct vehicle level benchmarking at the initial stage of any new project. From the benchmark information, the manufacturers can set relevant targets for their own vehicles under development. In this regard, an accurate prediction of the engine operating points can improve the correlation of the measured fuel economy of the benchmark vehicle. The present work describes a novel method that can be used for the accurate prediction of the engine operating points of any benchmark vehicle. Since the idea of instrumenting the crankshaft/driveshaft with torque transducers is a costlier and time-consuming process, the proposed method can be effective in reducing the benchmarking. Hence, the objective of this work is to develop a mathematical model to calculate the real-time engine operating points (engine speed and torque) using parameters like vehicle speed, accelerator pedal map, driveline inertia, vehicle coastdown force and gradient.

In automotive Body-In-White (BIW) structures, stiffness and the fatigue behavior is greatly influenced by the properties of its joints. Spot welding is one of the most widely used process for joining of sheet metals in BIW. Spot weld fatigue life under Accelerated Durability Test (ADT) is crucial for durability performance of BIW structures. Experience of BIW validations highlighted more number of spot weld failures in CAE when compared to actual tests. Hence, lot of iterations in the form of design modifications are required to be carried out to make these spot welds meet the targets which increases design & development time as well as cost. Current practice uses force-based approach for predicting spot weld fatigue life in CAE. To improve the spot weld fatigue life correlation, extensive study has been carried out on the approaches used for calculating spot weld fatigue life, namely force & stress-based approaches.

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.

Noise & sound quality has gained equal importance as that of emissions and crash safety of the vehicles. With increased engine power to weight ratio, the challenges for NVH engineers has increased multifold. Passenger compartment comfort levels are getting affected largely due to lighter and powerful engines. Same time, there is pressure to reduce overall vehicle weight and cost. This impose constraints to NVH engineer in designing the body structure and sound package to reduce the effect of powertrain forces and airborne noise on passenger compartment. In addition to weight constraints, there is trend emerging to use two & three cylinder engines which need to perform on par with four cylinder engines. This has shown adverse effect on vehicle NVH performance due to wider low frequency unbalance forces.

Increase in customer's awareness for better vehicle NVH has prompted automobile industry to address NVH issues more seriously. Among other critical vehicle systems for NVH, Air Intake and Exhaust Systems play an important role in terms of passenger compartment noise, sound quality and vehicle pass-by noise. Hence proper design & development of these systems is imperative to reduce their contribution in overall vehicle NVH. This needs to be achieved within constraints of meeting other functional requirements such as emissions and engine performance. The design parameters one needs to look at while developing the intake and exhaust system are mainly the acoustic transmission loss, structural noise radiations from the surfaces and structural isolation between body and these systems. This paper demonstrates the use of FEM approach for Vibro-Acoustic Analysis as a practical means for design of intake and exhaust system in terms of high transmission loss.

The ECE R-14, AIS015 safety standard specifies the requirements of the safety belt anchorages namely, minimum numbers, their locations, static strength to reduce the possibility of their failure during accidental crashes for effective occupant restraint and the test procedures. This standard applies to the anchorages of safety belts for adult occupants of forward facing or rearward facing seats in vehicles of categories M and N. ECE R14 ensures the passenger safety during sudden acceleration/retardation and accidents. Early simulations revealed some structural short falls that demanded cabin improvements in order to fulfill regulation requirements for the seal belt anchorage test. This paper describes the innovative design modifications done to meet the seat belt anchorage test. Good correlation with the test is achieved in terms of deformations. These simulation methods helped in reducing the number of intermediate physical tests during the design process.

In today's competitive automobile marketplace with reduced vehicle development time and fewer prototypes/tests, CAE is playing very crucial role in vehicle development. Automobile environment demands ever improving levels of vehicle refinement. Performance and refinement are the key factors which can influence the market acceptance of vehicle. Driveline is one of the key systems whose refinement plays critical role in improved customer satisfaction. Because of the virtue of the driveline functionality, driveline induced noise and vibration are the most common issues in the AWD vehicle development programs. Refinement of the drive line needs complicated nonlinear full vehicle CAE MBD models for the evaluation of driveline induced noise and vibration responses at different operating conditions [1]. In this paper a simplified approach is adapted for solving the Noise & Vibration issue which has been identified at the prototype testing level of an AWD vehicle development.

A tractor is vehicle specifically designed to deliver a high tractive effort at slow speeds for carrying out various agriculture operations like ploughing, rotavation etc. using implement. Hydraulic system is a key feature which connects these implements with the tractor. It controls the position and draft of the implement depending upon the type of crop, farming stage, implement type and soil conditions. These variations induces extreme range of load on the hydraulic system, thus making it challenging to design these components. Bell crank assembly is one of the main components of hydraulic system which controls the draft (thus, the loads experienced by tractor) through load sensing mechanism. Often bell crank assembly failures are reported from field due to uneven soil hardness and presence of rocks. This paper studies one of such bell crank assembly failures in the field. The failure was reported after half life cycle of usage during agriculture Operation.