Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Mechanical

The main pollutants from the automobiles are unburned hydrocarbons, nitrogen oxides (NOx), soot particles (PM), and carbon monoxides. Exhaust Gas Recirculation (EGR) is a technology used in diesel vehicles to reduce NOx. NOx are formed at high temperatures in the combustion chamber; EGR circulates a portion of exhaust gas to the combustion chamber after cooling it with the help of a heat exchanger known as EGR cooler. The main objective is to increase the efficiency of the EGR cooler by changing its material to copper, which has high thermal conductivity. The main challenge faced was the highly corrosive nature of copper, which was overcome by coating it with Graphene Oxide (GO) by the electrophoretic deposition process. Tests were performed using three EGR coolers made of stainless steel, copper, and GO-coated copper. The results show that EGR cooler with GO-coated copper has the highest rate of heat transfer. © 2020 SAE International.

School of Mechanical Engineering

Chennai Campus

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SAE Technical Papers

Graphene Oxide Coated on Copper-Based Exhaust Gas Recirculation Cooler for Future Automotive Engines

Phase change materials (PCM) are of attractive interest in electricity storage and power management applications. In this paper, PCMs are used for thermal management of an electric battery pack. Paraffin with a melting temperature of 58°C, OM35 with melting temperature of 35°C, two PCMs (paraffin and OM 35) were used for the study, as mixtures at two different ratios (50 : 50 and 60 : 40). Computations and experiments were allotted to estimate the heat transfer, solidifying and melting characteristics of the PCM utilised in the Li-ion cell battery module. Since PCM has low thermal conduction, thermal improvement techniques were investigated by inserting the copper plate into the PCM mixtures to boost the thermal conduction. PCM combination 50 : 50 is capable of holding battery running temperature compared to PCM combination 60 : 40. PCM combination 50 : 50 evidences to be ideal and lowered the operating temperature of the battery pack to 47°C. Copyright © 2020 Inderscience Enterprises Ltd.

International Journal of Electric and Hybrid Vehicles

Experimental study of lithium-ion battery cooling using mixture of phase change materials

Magnesium alloys have gained increasing attention for biomedical applications due to their biocompatibility and the biodegradability. Hydroxyapatite (HA) is known to be a highly bioactive because of its similar chemical and crystallographic structures to bone. Therefore, HA is believed to be a potential ceramic material for the fabrication of Mg based composites, to combine the advantages of both Mg and HA. But, in general, the composites known to be more susceptible to corrosion attack than the matrix alloy. Hence, in the present work, Sn is used as an alloying element to evaluate its effect on mechanical as well as corrosion properties of Mg/HA composites. Mg with 5 wt% HA and Mg-1 wt% Sn-5 wt% HA composites were prepared separately by stir assisted squeeze casting route. The phase analysis and microstructure were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) coupled with energy dispersive spectroscopy (EDS) respectively. Mechanical properties were evaluated by conducting the compression and micro hardness tests. Corrosion properties of as-cast composites were studied by linear polarization, Tafel and electrochemical impedance spectroscopy (EIS) techniques. The results of both XRD and SEM-EDS revealed that the main constitutional phases of as-cast Mg/HA composites were α-Mg and HA whereas, in Mg-Sn/HA composites, the phase Mg2Sn was observed along with fine distribution of HA particles. In both the cases, no interfacial reactions observed. The yield strength, ultimate compression strength and hardness were found to be increased with the addition of Sn in Mg/HA composites. Furthermore, the addition of Sn also played an important role in increasing the corrosion resistance of the Mg/HA composites which was attributed the refinement of grain size and the formation of Mg2Sn phase along the grain boundaries. Hence, it was concluded that the addition of Sn improves both mechanical and corrosion properties of Mg/HA composites. © 2019

Fulltext

Journal of Magnesium and Alloys

Mechanical and corrosion behaviour of hydroxyapatite reinforced Mg-Sn alloy composite by squeeze casting for biomedical applications

This paper presents a metallurgical failure analysis on failed material AISI 1020 bush used in industrial roller chains. This failure analysis study is carried out using the methodologies of metallographic analysis, scanning electron microscopy (SEM) analysis, chemical composition analysis and hardness analysis. In the inner diameter of the failed bush, numerous cracks originated and grew toward the outer diameter. The geometry of crack and surface fractures suggest failure is due to fatigue of impact. A quasicleavage significant feature occurred at the fracture surface very close to the crack initiation point. Simulation and experimental performance results of failed material (AISI 1020) and the proposed material (SAE 8620) are compared. The proposed material SAE 8620 has 233% higher crushing strength, 300% higher fatigue life cycles and 16.67% higher wear resistance compared to failed material AISI 1020. The conclusion presented is that alloy elements (chromium, nickel and molybdenum) in proposed SAE 8620 material significantly increase the performance of bush. Additionally, a roller chain with the proposed material SAE 8620 bush can be used for heavy shock load applications like mining drill rigs, balers, rotavators, construction loaders and combine harvesters. © 2020, ASM International.

Journal of Failure Analysis and Prevention

Metallurgical Failure Analysis and Improved Core Hardness to Enhance Crushing Strength, Wear Resistance and Fatigue Strength of Chain Bush

Green buildings form a milestone technology for a sustainable and eco-friendly atmosphere. A sophisticated process management and control with advanced warning systems and sustainable user-friendly buildings is their existing norm, as per the Indian Green Building Council. With efficient resource utilization and waste management along with different user-friendly working systems, these optimized building spaces reduce various utilization costs, parallelly increasing the safety, hygiene, and comfort standards. Their norms for the future eye at a sustainable development scheme using different renewable energy technologies with solar energy having developed as a fast-growing alternative due to its usability in various rural and urban dwellings. This paper discusses the concept of an automated voice recognition based vending machine powered by solar energy. The sophisticated Voice Recognition System (VRS) changes the role of humans in the associated process and hence, should be an integral part of future green buildings. Intelligence to the working system is incorporated by Machine Learning (ML) and its flexible Internet of Things (IoT) platform entails high customizability with a good Prognostics & Health Management (PHM) media. An implementation of the framework is worked upon, discussing the design of a food-dispensing unit that can be used in hostels, restaurants, and other areas of medium to a large gathering. Food can be served without any human intervention whilst maintaining high levels of cleanliness, minimizing waste, and reducing operating costs. © Published under licence by IOP Publishing Ltd.

IOP Conference Series: Earth and Environmental Science

Design &amp; Development of a Voice-Enabled Vending Machine for Green Buildings

Friction stir spot welding, a solid-state metal joining process has been utilised to join dissimilar aluminium alloys using pinless tools. The optimal welding conditions were predicted using the Multi-start algorithm with 25 starting points and were validated by confirmation tests. The Multi-start algorithm predicted the maximum tensile shear force of 6.28 kN at the tool rotational speed of 841.83 r/min, plunge depth of 0.618 mm, shoulder diameter of 24.99 mm, plunging speed of 0.04 mm/s and dwell time of 8 s. The scanning electron microscopy analysis revealed the formation of flatter hooks in the weld zone. The electron backscatter diffraction scans revealed a decrease in grain size at the lower sheet (Al 5754) due to the action of 30 kN axial force during pinless friction stir spot welding. Two different modes of fracture were observed: (i) nugget pull-out with necking; (ii) shearing. The fracture modes were observed to be dependent on the process parameters like shoulder diameter and plunge depth. © IMechE 2020.

Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science

Process parameter optimisation in pinless friction stir spot welding of dissimilar aluminium alloys using Multi-start algorithm

The main aspect of the mobile robot system is the ability to localize itself accurately and simultaneously, create an map of the unknown environment. Simultaneous localization and mapping (SLAM) is required for autonomous navigation. The framework of SLAM is based on Rao-Blackwellized Particle Filter (RBPF) that is applied through G-Mapping algorithm. The 2D LIDAR scanner and odometer is used as main sensor in the simulated robot model. The RBPF algorithm and the data of the LIDAR and odometer are fused to create the 2D map of the simulated environment as well as localization and navigation of the robot in unknown environment. Experiment Implementation is carried in Robotic Operating system (ROS) and gazebo simulator. © 2020 IEEE.

Proceedings - 2020 6th IEEE International Symposium on Smart Electronic Systems, iSES 2020

Simultaneous Localization and Mapping of Mobile Robot using GMapping Algorithm

The objective of this work is to investigate the effect of graphite addition to Al/SiC composites manufactured by stir casting process. The reinforcement content of graphite was varied from 2.5 wt. % to 7.5 wt. %, for preparing three types of hybrid composites. Al/SiC/Gr hybrid composites prepared by stir casting method have uniform dispersion of SiC and Gr particle reinforcement. High-speed machining of Al/SiC/Gr was done in CNC machine using PCD insert at a cutting speed of 300, 400 and 500 m/min. From ANOVA analysis, cutting speed (48.76%) is the critical factor affecting surface roughness. Grey Relational analysis was done for simultaneous improvement of Material Removal Rate and surface roughness. Roughness values were predicted using Taguchi method and predicted values were compared with experimental results. Elemental chips produced during machining leads to reduced roughness values. © 2020, © 2020 Engineers Australia.

Australian Journal of Mechanical Engineering

High speed machining and optimisation of Al/SiC/Gr hybrid metal matrix composites using ANOVA and grey relational analysis

For years, metals and their alloys are the primary sources for all types of general and structural applications. In other words, metals like Copper, Zinc, Aluminum, Cast Iron etc. dominated the world for centuries and got applications in fields like automotive components, aerospace engineering, sports and marine industries. But, as these metals and alloys are heavy in weight and also due to high manufacturing cost, the question of reducing the overall weight and cost of the structures without affecting the performance has raised and hence lightweight materials like plastics and composites have come into the picture. In this paper, Sheet molded compound composites have been reviewed in terms of characteristics, manufacturing, research challenges and way forward. © TJPRC Pvt. Ltd.

International Journal of Mechanical and Production Engineering Research and Development

An analysis of recent developments in sheet moulding compound composites and their mechanical performance

This research work focuses on the impact of graphite addition to the Al/SiC hybrid metal matrix composites manufactured by stir casting process. Three specimens were prepared with Al6061 alloy + 5 wt. % SiC and varying weight percent of graphite. Al6061 matrix material is suitable for machining and welding applications commonly used in construction of aircraft wings and fuselages. Machining of composite materials is often required to meet dimensional tolerances, surface roughness and to create holes. A layered SiC/Gr composite material is used in gas turbine combustor can. Machining of Al/SiC/Gr hybrid composite was done in Esteem ETM 356 lathe using tungsten carbide insert. Optimization of three machining parameters cutting speed, feed rate and depth of cut, was done using four levels. From ANOVA results feed rate (35.83%) is the important factor influencing surface roughness. Grey Relational analysis was done for simultaneous improvement of Material Removal Rate and surface roughness. © 2020, Faculty of Mechanical Engineering, Belgrade.