ARAI Journal of Mobility Technology

IC Engine Belt Auto Tensioner-Field Failure Resolution

R. Deepalakshmi — 2024-02-29

Failure of Auto tensioner was observed at engine of LCV segment vehicles. In this study both vehicle samples were analyzed to have a detailed investigation on the issue. In common, these failures can be caused due to assembly issues, adjacent parts incorrect mechanical parameters (belt tension, Arm movement, Angular vibration) and also by improper material selection etc. Issue was identified in pivot bush which is one of the sub assembly part in Auto tensioner. Where the bush material is with glass as a fillers in base polymer material of Nylon 66 matrix against the material specification on Nylon 66 with PTFE, MoS2 and Aramid as fillers. As glass is abrasive in nature eroded the mating part, hence caused the Auto tensioner system failure. This study revealed the failure is due to improper material composition of the pivot bush (sub assembly part) caused by raw material mix up at tier 2 supplier’s premises

Keywords: IC Engine, Belt Auto Tensioner, Field Failure, Tear Down Analysis, SEM Analysis, ASTM D5630

Adaptive MATLAB GUI for Hydraulic Brake Stopping Distance Simulation

Dileepan Anandan — 2024-04-15

The crucial segment of any vehicle is the braking unit which decides the vehicle’s performance and passenger safety on a large quotient. It is highly essential to decelerate the vehicle within a reduced distance to avoid any collision. The stopping distance is also dependent on many characteristics apart from the vehicle itself which are GVW(Gross Vehicle Weight), brake sizing, Road Friction, and other vehicle design parameters. Hereby, the result of any brake system is the Stopping Distance. Therefore, for every vehicle, it is inevitable to design in such a way that meets all requirements to pass the safety standards.

In this article, we provide an interactive GUI of Mathematical modelling using MATLAB that depicts the running vehicle simulation while the brakes are applied and highlights the Stopping distance for any given inputs. Here, we have used a novel approach to calculate the stopping distance, given we have all vehicle properties. Importantly, cuts the design phase to a large extent saving an ample amount of time with all ease of access and dexterity.

The core features of GUI:

One will be able to generate and compare stopping distance and other brake-related results for any two given different design scenarios.
GUI is automated so that it can simulate the stopping distance just by providing the brake/vehicle parameters inputs to the interface.
Additional functionalities to compare design results for various standards (FMVSS, IS, ECE) can also be done effectively.

Keywords: Braking Systems, MATLAB Application, Vehicle Safety, Stopping Distance

Battery Cell Thermal Control in Electric Vehicles Using Water Cooling Block

D. Sriram Sanjeev — 2024-04-15

Research and development efforts in the field of transportation have recently focused on creating clean, safe, and high-efficiency modes of transportation. It has repeatedly been predicted that electric, hybrid, and fuel-cell vehicles will soon displace conventional automobiles. This research offers an illustration of how a battery-electric vehicle may regulate the flow of coolant over specific battery cells. Each lithium-ion battery cell's heat level is measured by a sensor, which also controls the cooling process. The PID controller (Arduino) and Water Pump both function using a 12V rechargeable battery. Temperature sensors are employed to monitor each Li-ion battery cell independently and provide feedback as an analog signal. The flow of the pump is controlled by the battery's feedback, and the coolant goes via a convey to achieve temperature control. When compared to lead-acid / nickel-metal hydride batteries, lithium-ion batteries offer better energy densities. Moreover, it is far less expensive and doesn't need nickel or cobalt. Also, it is safer since it is more stable. Each battery cell has a water cooling block installed specifically for more effective cooling. When compared to the method of calculating the total battery heat without any controller on any individual cells of the battery, the method of implementing a water cooling block in individual cells will be more effective. The temperature variation in the battery cell was significantly decreased by a water cooling block, which also lowered the thermal effect by around 40%. In the battery cell, a number of cycles and the depth of discharge are recorded, and the findings show that while the coolant temperature rises from roughly 30°C to 50°C, the battery cell's interior temperature drops drastically from 60°C to 20°C of heat.

Keywords: Lithium-ion Battery, Temperature Monitoring, Temperature Management, Predictive Algorithms, and Sustainability

Brake Hose–Field Failure Elimination

R. Deepalakshmi — 2024-04-15

In LCV segment vehicles were reported for complaint on Spongy brake pedal. In brake assembly parts constitutes of Brake oil reservoir, Rubber brake hose, TMC cylinder and etc. In this study assembly wise and material wise investigations on failed samples were analyzed to understand and resolve the issue. In common these kind of failures can be caused due to contamination of brake fluid, improper material grade usage and also sometimes by assembly issues. Issue identified as that the brake hose in the assembly hardened and not meeting as per the drawing material grade specifications. The plasticizer from brake hose is leaching out to the brake oil and contaminated oil, passes through the TMC cylinder and making EPDM seals to swell. Because of swelling the seal is not seating properly in the groove which results in poor pressure build up in TMC and subsequent spongy brake observed. This study revealed the Improper selection of EPDM grade for the brake hose.

Keywords: Brake hose, Field failure, LCV segment vehicles, failure elimination, Tear Down Analysis, Thermo Gravimetric Analysis

Studying Modern Formula 1 Front Wing at Medium Cornering Speeds

P. Nimje — 2024-04-15

A simulation-based study of three different types of front wing designs used in modern Formula 1 cars was done. The study mainly focuses on the aerodynamic forces that a Formula One car generates mainly the Downforce, the Drag force, & the Lateral force at low cornering speeds. These forces were studied in detail & taking a closer look at how they migrate during the dynamic conditions the car is thrown at various Side Slip (Yaw) Angles, these results were compared with the wing Scuderia Ferrari used in the 1998 formula 1 championship to better understand the inherent problems faced in those previous designs. A brief study of the flow field & flow lines was conducted along with the vortex generation for all three wings. Vortex formation and management is a prominent part of research being carried out for a formula 1 car, so a brief study on the phenomenon of vortex generation & Y250 vortex formation was also carried out. The studies were carried out over typical medium-speed corners where the speed ranges between 150-220 KM/Hr. A study on the effect of the flow field of the top element on the lower element was carried out where the 5th element was removed from each of the three wings & the effect on the downforce & drag value was analysed along with the pressure field.

Keywords: Modern formula 1, Front wing designs, Cornering speeds, aerodynamic forces, Side Slip (Yaw) Angles, Centre of pressure (CoP), Lateral force, CFD, Downforce

Simulink Model for LMV and Conceptualization of 2 Speed E-Axle

Rohan Sandeep Mahatekar — 2024-04-15

Heavy-duty trucks are the primary contributor to the global emissions of greenhouse gases. Because of this, electric haulage has seen significant growth in popularity. Electric heavy-duty trucks aren't widely adopted because of their limited range, payload capacity, and high prices. Electric axle systems, sometimes known as "E-Axles," are capable of electrifying heavy-duty vehicles effectively. The motor, power electronics, and gearbox are all combined into one unit in an E-axle. E-axles that are devoid of motors and gearboxes have the potential to boost performance while also reducing weight and fuel consumption. Heavy-duty automobiles are similar to them. E-axles have the potential to increase the fuel efficiency, flexibility, and emissions of heavy-load trucks. The e-axles are being inspected. E-axles for heavy-duty trucks bring both issues and opportunities concerning finances, infrastructure, and costs. Examine the performance standards as well as the technology behind batteries. This paper provides an introduction to MATLAB Simulink, which focuses on engineering and science. Simulink facilitates the design, simulation, and evaluation of systems. This article demonstrates the fundamental principles, features, and benefits of Simulink through the application of system modeling, control design, and dynamic simulation. It presents Simulink methodologies, libraries, and blocks, as well as interactive simulations.

Keywords: MATLAB, Simulink, EV Control systems, EV simulation, EV powertrain modeling, EV test and validation Simulink, WLTP drive cycle

Design Optimization of LCV CAB for Frontal Pendulum Test: Enhancing Survival Space Improvement Through Frugal Load Path Transfer Techniques

G. Raghuraman — 2024-04-15

In the fiercely competitive landscape of the automotive industry, Original Equipment Manufacturers (OEMs) encounter substantial challenges in the realm of Research and Development (R&D), particularly in the pursuit of lightweight design without compromising safety. As a result, the automotive sector continuously seeks innovative tools and methodologies to substantially optimize the structural composition of Light Commercial Vehicle (LCV) segments. The design of lightweight cabins, while simultaneously ensuring crashworthiness, not only plays a pivotal role in determining the market success of a new LCV but also holds significant legal implications. One well-established and indispensable evaluation tool to ascertain compliance with critical homologation requirements is the frontal pendulum test. This test serves as a litmus test for the appropriate design of Body in White (BIW) architecture, crucial for safeguarding occupant safety in unforeseen emergency scenarios.
Within the context of adhering to styling themes and the design intent governing the three-dimensional (3D) geometry, a notable deviation emerged in the form of a 33 mm extension of the front panel in the newly stylized cabin. This deviation presented CAB engineers with a formidable challenge, as it disrupted the conventional load path of the frontal pendulum, rerouting it to the CAB itself instead of the intended transfer to the frame via the bull bar. The primary objective of this work is to restore the load path to the frame, all the while adhering to the original styling intent and refraining from introducing any additional modifications to major adjacent components such as the bumper and bumper reinforcement. Furthermore, this undertaking extends to encompass an exploration of cost reduction opportunities within the ambit of the newly styled CAB.

Keywords: LCV CAB, Frontal Pendulum, Frugal Load, Occupant safety regulation, Styling impact, Pendulum impact, CAE simulation

Effect of Heat Treatment on Magnetic Properties of EN8D Steel Used in Automotive Applications

Dr. S. C. Bali — 2024-04-15

The present study focuses on achieving the optimum combination of mechanical and magnetic properties for EN8D steel. SAE 1010 and EN8D steels are the candidate materials to manufacture the fixed nucleus of the disk-type electro-mechanical horn. Both materials have either good magnetic or mechanical properties. The main function of fixed nucleus is to get magnetized and pull the mobile nucleus towards it. However, as magnetization and demagnetization take place in the range of 300-500 Hz, fixed and mobile nucleus continuously strikes each other at high frequency. Due to such high frequency working condition, fixed nucleus is prone to failure under wear and tear or under fatigue. For this kind of application, a combination of magnetic and mechanical properties is required in the material used to manufacture fixed nucleus. Thus, in current paper, the effects of chemical composition, microstructure, hardness, strength and toughness of EN8D steel before and after austenizing and tempering heat treatment are evaluated and compared with as-rolled EN8D and SAE 1010 steels, which are mostly used for manufacturing fixed nucleus. Magnetic permeability was evaluated using JMatPro software and compared. Austenizing treatment is performed at 900 °C for 1 hour, followed by water quenching. Tempering treatment of the same was performed at 550 °C for 2.5 hours. The Ultimate Tensile Strength (UTS) and hardness of EN8D after heat treatment decreased from 917 to 781 MPa and 269 to 233 HV0.1 respectively. Charpy V-Notch (CVN) toughness of EN8D steel after heat treatment increased from 12 to 45 joules. It indicates that the decrease in strength and hardness resulted into increase in toughness. Microstructure changes from ferrite and pearlite to combination of tempered martensite, ferrite and bainite. Magnetic permeability evaluated by JMatPro software shows increment from 450 to 564 Gauss/Oersted in EN8D steel after heat treatment.

Keywords: Electro-mechanical horn, fixed nucleus, magnetic permeability, JMatPro, SAE1010 steel, EN8D steel

Comparative Analysis of Transmission Housings to Evaluate Whining Noise Performance

Kalyan Deepak Kolla — 2024-04-15

A quite cabin is always a preferred choice of the customer. Powertrain acts as a source for many noise and vibration problems in a passenger car. Transmission plays a major role in modulating the power from engine to the drive train and is exposed to a high vibration and noise environments. Hence design of transmission for low vibration & noise is need of the hour. This paper attempts to perform a comparative study of 6 housings of different design of a two-wheel drive passenger car to evaluate the vibration performance and Noise radiation characteristics by using FEM (Finite Element Method) & BEM (Boundary Element Method) & finite element analysis techniques. The authors also try to put forward a layout comparison study for the housings and conclude what design is best suited for better NVH whine performance in view of vibrations & sound radiation. These indicative results from this paper can be referred by the design & analysis engineers during early product development of the transmission.

Keywords: Transmission, Housings, Whining Noise, Bionic Design, NVH Analysis, Durability Analysis, Study of Housings, Housings NVH Analysis

Rear Axle Whine Reduction by Gear Contact Patch Optimization

Atul A Gaikwad — 2024-04-15

In-cab whine is a highly annoying phenomena in all the category of vehicles. The in-cab noise of passenger vehicle with Rear Wheel Drive ( RWD) considered for this study consist of axle whine noise. The whine noise is heard at multiple speeds during Wide Open Throttle (WOT) as well as coasting. To resolve the issue of whine noise, series of measurement are carried out to identify the source and transfer path of the whine. The noise measurement revealed that rear axle pinion mesh order is responsible for in-cab whine. It is confirmed through measurement that the whine is structure borne. The order based operational deflections shapes of rear axle show excessive vibration on differential nose in affected speed zones. It is thus learnt that whine is due to poor contact pattern of pinion and crown wheel of the rear axle. The three resonances in operation range amplify this mesh order resulting in whine. It is decided to work on noise source i.e. gear rather than transfer path. The hypoid gear design is optimized through Tooth Contact Analysis (TCA). The lapping and heat treatment processes of gear manufacturing are modified. The contact pattern of optimized gear is identified on gear tester machine. Significant improvement is observed in contact pattern. The in-cab noise measurement is carried out with optimized hypoid gear and it is found that the whine is completely eliminated.

Keywords: Rear axle, Whine reduction, Gear contact, Patch optimization, Rear Wheel Drive, Whine Source, Vibration on Transfer Paths, Noise Generation, Hypoid Gear, Heat Treatment

Editorial

Dr. B V Shamsundara — 2024-02-29

Dear Readers,

In the fast-paced landscape, modern transportation is undergoing a profound transformation, driven by technological innovation, changing consumer preferences, and the need for sustainability. In the country, from urban areas to remote rural areas, the evolution of mobility technology is restructuring the way we navigate, unlocking new opportunities for efficiency, sustainability, and accessibility. As we stand at the threshold of a new era in mobility, it's essential to explore the innovative technologies driving this revolution and their potential to redefine the future of transportation.

ARAI Journal of Mobility Technology takes pride in presenting its Jan–Mar 2024 issue that covers IC engine technology, Brake hose failure analysis, modeling on different technologies, battery and EV related subjects, and vehicle dynamics. The ARAI Journal journey is not just about getting the technologies which are about shaping the future of transportation and society as a whole.

Electric vehicle technologies are poised to revolutionize the future of transportation, offering a cleaner, more sustainable alternative to traditional gasoline-powered cars. With growing concerns about climate change and environmental sustainability, the shift towards electric propulsion represents a significant step forward in reducing carbon emissions and mitigating the effects of climate change.

With ongoing advancements in battery technology, charging infrastructure, and vehicle design, EVs are becoming increasingly practical and accessible for consumers around the world. By embracing innovation, fostering collaboration, and addressing the challenges ahead, we can accelerate the transition to a cleaner, greener transportation system that benefits both people and beyond electrification, automotive technologies are also driving progress in safety and convenience. Advanced driver-assistance systems (ADAS) such as adaptive cruise control, lane-keeping assist, and automatic emergency braking are becoming standard features in modern vehicles, helping to prevent accidents and save lives. Moreover, the emergence of autonomous driving technology promises to revolutionize transportation by eliminating human error and making roads safer for everyone. ARAI Journal is a gateway for all researchers, industry professionals, students, faculty to discover the latest technologies and advancements driving the automotive industry forward on the planet.

In the midst of life's challenges and uncertainties, may this journal be a source of solace and strength, reminding you of your resilience and inner wisdom. May it be a space where you can find clarity, purpose, and peace amidst the chaos of daily life.

I want to extend my warmest wishes to each and every reader of this journal.