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Regenerative braking is an effective approach for electric vehicles (EVs) to extend their driving range. To enhance the braking performances and regenerative energy, regenerative braking control strategy based on multi objective optimization is explained in this paper. This technical paper would be focusing on extracting optimum Range with effective brake performances without affecting drivability and performances in different drives modes. An extensive research study on public road driving patterns is done to understand the percentage utilization of brakes at various (low-mid-high) speeds as per the customer driving behavior. Multi-Objective optimization function with three vital factors is defined where output generated power, torque smoothness and current smoothness are selected as optimization objective to improve the driving range, braking comfort, and battery lifetime respectively.

The purpose of this study is to conduct dynamic seat pressure mapping on vehicle seats during its operation on different test tracks under ambient environmental conditions for a defined speed. The test track comprises of pave roads, high frequency track, low frequency track and twist track. The variations in pressure distribution on seat during diverse road load inputs help to understand the seat cushion and back comfort for unique percentiles of human subjects ranging from 50th to 95th percentile population. For conducting the study, a sport utility vehicle (SUV) loaded with leatherette seats has chosen. Totally six participants (human subjects), five male and one female selected for the study based on their BMI (Body mass index) and body morphology. Pressure mats suitable for taking dynamic load inputs and able to log the data at a defined sampling rate mounted on seats and secured properly. The pressure mats should cover the seat cushion, bolster areas and back seat completely.

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.

In this current fast-paced world, releasing a defect free product on time is of utmost importance in the automotive domain. The automobile powertrain is designed with a fine balance of weight and power. Clutch, an intermediate part between engine & transmission in manual transmission vehicle plays crucial role for vehicle smooth drive & functionality. Hydraulic clutch slave cylinder (CSC) which is a part of clutch release system was observed with one failure mode in one of the vehicles during internal road validation. It facilitates to actuate the clutch diaphragm in order to disengage the clutch when clutch pedal is pressed and to re-engage the clutch back when the clutch pedal is released. CSC failure directly disconnects the response of leg to clutch and thus driver may lose vehicle control and can possibly cause a severe vehicle crash.

Automotive manufacturers are constantly working towards enhancing the driving experience of the customers. In this context, improving the static and dynamic gear shift quality plays a major role in ensuring a pleasant and comfortable driving experience. Moreover, the gear shift quality of any manual transmission is mainly defined by the design of the synchronizer system. The synchronizer sleeve strut detent groove profile plays a vital role in defining the performance of the synchronizer system by generating the minimum required pre-synchronization force. This force is important to move the outer synchronizer ring (blocker ring) to the required index position and to wipe-out the oil from the conical friction surfaces to build rapid high cone torque. Both these functional requirements are extremely critical to have a smooth and quick synchronization of the rotating parts under dynamic shift conditions.

The 48V mild-Hybrid system uses a 48V Lithium - Ion battery pack to boost the engine performance, to harness recuperative energy and to supply the accessory boardnet power requirement. Thermal management of the 48V battery pack is critical for its optimal utilization to realize the mild hybrid functionality, to meet CO2 reduction targets and useful life particularly under usage in hot ambient conditions. This paper discusses the various challenges and options of thermal management for the 48V battery pack based on the usage pattern and environmental conditions. The lifetime for a passively cooled battery pack is estimated for a typical Indian usage pattern. Active-air cooling is evaluated for the thermal management of the 48V mild-Hybrid battery pack. The tradeoffs are compared in terms of availability of hybrid functions and battery life.

Ride is essentially the outcome of coupled dynamics of various involved sub-systems which make it too complex to deal analytically. Tires, amongst these, are known to be highly nonlinear compliant systems. Selection of tires specifications such as rated tyre pressure, etc. are generally decided through subjective assessment. While experts agree that tyre pressure affects the attributes such as ride to a noticeable degree, the quantification of the change often remains missing. In the current work, vibration levels of various sub-systems relevant to ride in an SUV are measured for three different tyre pressures at different speeds over the three randomly generated roads. For the purpose, artificial road profiles of classes A, B and C are synthesized from the spectrum of road classes defined in ISO 8608:2016 and reproduced on a four-poster test rig.

This study presents a method for a cool down simulation of passenger compartments. The purpose was to integrate the 3D Computational Fluid Dynamics (CFD) software StarCCM+ with the 1D thermal management software KULI. The targets were to achieve accurate prediction of temperature diffusion inside the cabin for a transient cycle simultaneously reducing the modelling effort and CPU-time consumption. The 1D simulation model was developed in KULI and the flow field data required to simulate mass flow and diffusion inside the cabin was implemented from Star CCM+. The simulation model consists of a multi-zone cabin and models the complete refrigerant circuit consisting of evaporator, condenser, Thermal Expansion Valve (TXV) and compressor. This paper describes the process flow, definition of the inputs required and finally the validation of the simulation data with experiments.

Automotive industry has led to constant production innovation among manufactures. This has resulted in the reduction of the life cycle of the design philosophies and design tools. One of the performance factors that have continues to challenge automotive designer is to design and fine tune the braking performance with low cost and short life cycle. Improvement in braking performance and vehicle stability can be achieved through the use of braking systems whosebrake force distribution is variable. Braking force distribution has an important and serious role in thevehicle stopping distance and stability. In this paper a new approach will be presented to achieve the braking forcedistribution strategy for articulated vehicles. For this purpose, the virtual optimization process has beenimplemented.

Fierce competition in India’s automotive industry has led to constant production innovation among manufactures. This has resulted in the reduction of the life cycle of the design philosophies and design tools. One of the performance factors that have continues to challenge automotive designer is to design and fine tune the braking performance with low cost and short life cycle. Braking performance of automotive vehicle is facilitated by the adhesion between the tyre and the ground. Braking force generated at the wheels of a vehicle have to appropriately match to the adhesion. Antilock braking system (ABS) is used for this purpose. ABS is a modern braking system which could significantly improve directional stability and reduce stopping distance of a vehicle. However this system still too complicated and expensive to use in low end compact car and pickup truck.

Heat exchangers are thermoregulatory system of an automotive air conditioning system. They are responsible for heat exchange between refrigerant and air. Sizing of the heat exchanger becomes critical to achieve the required thermal performance. In the present work, the behavior of heat exchanger with respect to change in size is studied in detail by developing a scaling model. The limited experiments have been conducted for 3 different condensers. Commercially available 1D tool GT Suite is used for simulations. The heat exchangers are modeled using COOL3D module of GT Suite. The experimental thermal capacities of heat exchanger are compared with the simulated values. A good agreement up to ±2.3% is found between the experiments and simulations. Then developed scaling model in GT Suite is used for predicting the thermal behavior of heat exchangers by changing the size of the heat exchanger. Scaled thermal capacities of each model is compared with the corresponding experimental results.

For the thermal management of an automobile, the induced airflow becomes necessary to enable the sufficient heat transfer with ambient. In this way, the components work within the designed temperature limit. It is the engine-cooling fan that enables the induced airflow. There are two types of engine-cooling fan, one that is driven by engine itself and the other one is electrically driven. Due to ease in handling, reduced power consumption, improved emission condition, electrically operated fan is becoming increasingly popular compared to engine driven fan. The prime mover for electric engine cooling fan is DC motor. Malfunction of DC motor due to overheating will lead to engine over heat, Poor HVAC performance, overheating of other critical components in engine bay. Based upon the real world driving condition, 1D transient thermal model of engine cooling fan motor is developed. This transient model is able to predict the temperature of rotor and casing with and without holes.

The bias flow in Concentric Tube Resonator (CTR) is a flow-induced phenomenon in which the pressure gradient along the radial direction is produced by the kinetic energy of the flow. As a result, the flow dynamics in CTR is characterized by bias flow into the annular cavity in the upstream and outflow from the annular cavity in the downstream of the flow. This is due to the change in direction of the radial component of the bias flow at a point called the point of recovery, as a consequence of mass conservation. The pressure drop of CTR is a complex function of the momentum flux and other geometric parameters such as porosity, open area ratio, discharge coefficient of the perforated holes, bias inflow, bias outflow, grazing flow and length. In this study, numerical experiments are conducted to obtain an empirical formula for the friction factor of perforated pipes which are extensively used in automotive mufflers.

The prime focus of automotive industries in recent times is to improve the energy efficiency of automotive subsystem and system as whole. Harvesting the waste energy and averaging the peak thermal loads using thermal energy storage (TES) materials and devices can help to improve the energy efficiency of automotive system and sub-system. The phase change materials (PCM) well suit the requirement of energy storage/release according to demand requirement. One such example of TES using PCM is extended automotive cabin comfort during vehicle idling and city traffics including start/stop of the engine at traffic stops. PCM as TES poses high density and capacity in thermal energy storage and release. It is due to latent heat absorption and release during phase change. Generally the latent heat of a material compare to it sensible heat is much higher, almost an order of 2. For example, latent heat of ice is almost 160 times higher than sensible heat for a kelvin temperature rise of ice.

Hybrid Electric Vehicles (HEVs), Plug-in Hybrid Electric Vehicles (PHEVs), Extended Range Electric Vehicles (EREVs), Battery Electric Vehicles' (BEVs) development is gaining traction across all geographies to help meet ever increasing fuel economy regulations and as a pathway to offset concerns due to climate change and improve the overall green quotient of automobiles. These technologies have primarily shifted towards Li-ion batteries for Energy Storage (due to energy density and mass). In order to make actual business sense of these technologies, of which, battery is a major cost driver, it is necessary for these batteries to provide similar performance and life expectancy across the operating and soak (storage) range of the vehicles, as well as provide the requirements at a competitive cost.

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.