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

An underwater glider is a most commonly used unmanned underwater vehicle but it has limitations to avoid obstructions in its path. To overcome this problem, the application of obstacle avoiding system is needed. This paper describes the development of an unmanned underwater vehicle (UUV) with integration of sensor-actuator network to avoid obstacles. To study the hydrodynamic behaviour of the proposed UUV, computational fluid dynamics (CFD) is carried out by considering pure surge and heave motion. The UUV is equipped with obstacle avoidance system with infra-red (IR) sensor and wireless communication module. Experimental tests are conducted to understand the behaviour of the UUV in low depth water surfaces and also to validate the CFD simulation results. The UUV’s development, motion analyses and preliminary tests in obstacle avoidance are reported. Copyright © 2020 Inderscience Enterprises Ltd.

School of Mechanical Engineering

Chennai Campus

World University root node

Fulltext

International Journal of Advanced Mechatronic Systems

Obstacle avoidance system and wireless communication for an unmanned underwater vehicle for low depth water surfaces

A vortex tube is a device, which uses pressurised inlet gas to split into hot and cold separate streams. This phenomenon is referred to as energy separation. The literature behind the energy separation in vortex tube is huge as the device was invented in 1933. The improvement in the performance of the device and the working principle behind the energy separation has been the topic of interest to many researchers around the globe. However, the ability to produce hot/cold gases without mechanical device finds promising applications in literature. This review article recommends the usage of vortex tube to many diverse fields of applications. The operational parameters involved in every application are tabulated and studied. The collection of articles on counter-flow vortex tube oriented towards the application provide the reader a fascinating choice in recovering energy from pressurised gas and ability to meet certain applications required in a particular industry. © 2020 Engineers Australia.

Australian Journal of Mechanical Engineering

Review of vortex tube: a sustainable and energy separation device for multi-purpose applications

Polymer matrix composites (PMCs) generally use the inorganic and non-biodegradable materials as reinforcements. This paper presents a PMC with reinforcement of fly ash and banana fiber. The epoxy resin is used as a matrix. This paper investigates the influences of the percentage of fly ash, the percentage of banana fiber and the size of banana fiber on tensile and flexural behaviors of fly ash and banana fiber reinforced epoxy matrix composite. Taguchi’s orthogonal array is used in the design of the experiments in the sample preparations. Analysis of variance (ANOVA) is employed to find the significance of input parameters on tensile and flexural behaviors. © 2020, Polish Academy of Sciences. All rights reserved.

Department of Manufacturing Engineering

Vellore Campus

Engineering Transactions

Investigations on tensile and flexural characteristics of fly ash and banana fiber-reinforced epoxy matrix composites

BACKGROUND: Work-related health problems result in an economic loss of 4-6% in GDP (Gross domestic Product) of the most countries. In the industrialized countries, 1/3rd of the health-related absence to duty are due to musculoskeletal disorders. Professional driving is one such occupation which looks like sedentary occupation, but involves many risk factors that contribute to work-related musculoskeletal disorders (WMSD) due to its nature of working and work environment. This research describes the various risk factors associated with WMSDs and their effects on drivers health. OBJECTIVE: To assess the prevalence of WMSD and its associated risk factors among the bus drivers of Karnataka State Road Transport Corporation (KSRTC), Karnataka. METHODS: Subjects considered in this study are 301 full-time bus drivers from the central division KSRTC which consists of 6 depots in Bengaluru. Information regarding reported WMSD symptoms during immediate past 7 days to 12 months, the intervention of WMSD in their day-to-day life and the overall comfort of the body are determined through Standardized Nordic Questionnaire and also by direct observation. The survey questionnaire is conducted by face to face interview. FINDINGS: From the statistical analysis, it is found that around 55.8% of the study population has experienced WMSD. The prevalence of WMSD is most common in the age group of 29-39 years (53.5%) followed by the age group of >40 years. CONCLUSION: In this study, some of the work-related and lifestyle/health-related factors show significant association with WMSD in bus drivers of Karnataka. Musculoskeletal disorders can be prevented by designing the driver's workspace ergonomically so that the design suits to all sorts of drivers and the drivers should also be trained on basics of vehicle ergonomics (posture, seat adjustments, in-vehicle controls adjustments). INTERPRETATION: KSRTC should educate drivers on the basics of vehicle ergonomics, harmful use of tobacco/alcohol, unhealthy food habits and also to involve in physical exercise at least 75-150 mins weekly. If not, the trend of drivers suffering from WMSD belonging to mid-age will increase exponentially. SCOPE FOR FUTURE WORK: Statistical result and direct observation insist on undertaking further studies on ergonomic interventions at driver's cabin, lifestyle/occupational health factors which mitigate WMSD in different parts of the body during driving. © 2020-IOS Press and the authors. All rights reserved.

Work

Prevalence of work related musculoskeletal disorders among occupational bus drivers of Karnataka, South India

Phase Changing Materials (PCM) is proving to be one of the major breakthroughs in industries as it has various applications in sustainable and renewable energy. The present study investigates the melting and solidification of phase change material (ice) in the presence of titanium oxide nanoparticles in a horizontal channel with internal heat source. The parametric study is carried out by varying the inlet velocity, heat source strength and nanoparticle volume fractions. The problem is modeled as three-dimensional laminar steady flow considering the effects of melting and solidification using Ansys Fluent. The heat sources mounted at the lower wall of the channel are specified with constant wall temperature boundary condition and the remaining walls are considered as adiabatic. The forced velocity inlet boundary condition is specified for the longitudinal velocity at the inlet and pressure outlet boundary condition is considered at the outlet of the channel. The results are analyzed by plotting the pathlines, longitudinal velocity contours, pressure and temperature contours. The results indicate that the longitudinal inlet velocity significantly affects the flow and heat transfer characteristics inside the horizontal channel. The increase in inlet velocity strengthens the melting rate and increases the heat transfer rate inside the channel. It is also found that the melting rate increases linearly with increase in the heat source intensity and nanoparticle volume fraction. © Published under licence by IOP Publishing Ltd.

IOP Conference Series: Earth and Environmental Science

Simulation of heat transfer characteristics of phase change material dispersed with Titanium oxide nanoparticles in horizontal channel

This paper presents the influence of peak current and induced ultrasonic vibration into the dielectric medium during powder mixed electrical discharge machining (PMEDM) process. Molybdenum-di-sulphide powder of 90nm size is used as conductive particle mixed in hydrocarbon based dielectric medium during EDM process. Peak current is varied at 0.5A, 2A, 9A and 21A; parameters such as pulse duration 10μs, gap voltage 20V and duty factor 2 were maintained constant. Two set of experiments were conducted by varying peak current; one by induced ultrasonic vibration during PMEDM and another without ultrasonic vibration. The effect of peak current and ultrasonic vibration on material removal rate, surface roughness and crater diameter were analysed. Scanning electron microscope images and 2D roughness profile were used to analyse surface integrity. It is observed that the induced ultrasonic vibration improves MRR by 6 times, surface roughness (Ra) of 1.464 µm, small crater diameter and debris free surface is achieved. © Published under licence by IOP Publishing Ltd.

IOP Conference Series: Materials Science and Engineering

A study on influence of peak current and ultrasonic vibration during powder mixed electrical discharge machining process

• The increase in forced ventilation velocity reduces plume longitudinal propagation. . • Vent discharge rate increases with increase in Grashof number. . • Under forced ventilation, mass flow rate is higher through downstream roof vent. . • Increase in volume blockage reduces the plume buoyancy force . • Mass flow rate through roof vents decreases with increase in volume blockage ratio.. © 2020 Elsevier Ltd The objective of this study is to numerically investigate the effects of volumetric blockage ratio on the thermal plume behavior in a mixed ventilated tunnel with heat source and vehicular blockage. The tunnel model consists of three naturally ventilated roof openings and longitudinal ventilation is provided by supplying forced air through the tunnel inlet port. The non-Boussinesq variable density approach is used to model the high thermo-buoyant flows with large eddy simulations (LES) turbulence model discretized by finite difference method (FDM). The investigation is performed by varying the Grashof number (Gr) in the range 108 ≤ Gr ≤ 1010 and the forced ventilation velocity (Uc) and volumetric blockage ratio (ξ) are varied between 0.05 ≤ Uc ≤ 0.5 and 0.012 ≤ ξ ≤ 0.05. The outcome of this study emphasizes that the longitudinal ventilation and volume blockage ratio significantly affects the thermal plume behavior and venting efficiency of the roof openings. It is found that inertial force from forced air increases the mass flow rate through downstream vent in comparison with the upstream vent. It is observed that the increase in Grashof number enhances the bidirectional exchange rate through roof vents and an increase in volume blockage ratio decreases the discharge rate through the roof openings. © 2020 Elsevier Ltd

Journal of Wind Engineering and Industrial Aerodynamics

Influence of volume blockage ratio on turbulent buoyant plume dispersion in mixed ventilated tunnel

In terms of mechanical, chemical, and corrosion properties, the current research investigates the effect of nanotube’s length by increasing the water content on the electrolyte. Self-assembled titanium dioxide (TiO2) nanotube was synthesized by electrochemical anodization using a neutral medium of ethylene glycol and ammonium fluoride. The experiments were carried out with two different water vol%. Subsequently, crystalline phases were achieved by annealing the sample at 550 °C. A scanning electron microscope confirmed that an increase in water content elevates the length of nanotube by three times than under normal conditions. The results demonstrate that the increased length of nanotube thus attained enhanced corrosion resistance and mechanical properties. © 2020, Springer Nature Switzerland AG.

Journal of Bio- and Tribo-Corrosion

Anodic Synthesis of TiO2 Nanotubes Influence of Water Content and the Analysis of the Nano-Mechanical Application

Stringent emission norms being followed throughout the world increases the demand for clean and green fuels. Gaseous fuels like compressed natural gas (CNG), liquefied petroleum gas (LPG) and hydrogen are promising alternatives to conventional diesel and gasoline. The use of hydrogen in the IC engine has gained interest among the researchers as it can be easily produced from water through electrolysis. Electrolysis of water produces stoichiometric mixture of hydrogen and oxygen in the ratio of 2:1. This study investigates the performance and emission characters of introducing hydrogen and HHO gas in the inlet manifold of a compression ignition engine in dual fuel mode. Experiments were conducted at 5 different torque conditions where hydrogen and HHO gases are supplied at the flow rate of 6, 12, 18, 24, 30 and 36 LPM along with air in the inlet manifold. The HHO gas was synthesized using stored hydrogen and oxygen in the ratio of 2:1. The performance and emission characteristics were noted for all the conditions. The introduction of hydrogen and HHO gas has reduced the diesel energy share ratio by 86% and 70% respectively at no torque condition. HC emission was found to be decreased at high torque condition when compared to neat diesel operation. Significant increase in NOx emission was noted with increase in gases substitution and torque. CO2 and smoke emissions showed positively decreasing trend as the gas percentage increases, due to reduction in carbon content of the fuel mixture. The cylinder pressure reduced with increase in the flow rate of gases. Combustion duration increases with increase in flow rate as well as increase in torque. It was noted that Brake Thermal Efficiency (BTE) reduced for all operating conditions except at 6 LPM of HHO gas addition in the combustion chamber. © 2020 Hydrogen Energy Publications LLC

International Journal of Hydrogen Energy

Experimental investigations on performance, emission and combustion characteristics of Diesel-Hydrogen and Diesel-HHO gas in a Dual fuel CI engine

Prediction of an organization's performance has become essential for any organization for its potential customers to place orders with confidence. Overall Equipment Effectiveness (OEE) is one of the acknowledged measures for performance monitoring. In this paper, two different techniques, a simple moving average and Holt's double exponential smoothing methods, are used to evaluate OEE and to predict the future performance of overall equipment effectiveness in R studio. Holts Double exponential smoothing method was found to result in minimum error measured by mean absolute deviation. Python program is to predict major losses to improve the productivity of the organization by management. © University of Novi Sad.