Department of Mechanical Engineering

Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

Electrochemical machining is one of the widely used non-traditional machining processes to machine complicated shapes for electrically conducting but difficult-to-machine materials such as superalloys, Ti-alloys, alloy steel, tool steel, stainless steel, etc. Use of optimal ECM process parameters can significantly reduce the ECM operating, tooling, and maintenance cost and will produce components of higher accuracy. This paper investigates the effect and parametric optimization of process parameters for Electrochemical machining of EN-31 steel using grey relation analysis. The process parameters considered are electrolyte concentration, feed rate and applied voltage and are optimized with considerations of multiple performance characteristics including material removal rate, overcut and cylindricity error. Analysis of variance is performed to get contribution of each parameter on the performance characteristics and it was observed that feed rate is the significant process parameter that affects the ECM robustness. The experimental results for the optimal setting show that there is considerable improvement in the process. The application of this technique converts the multi response variable to a single response Grey relational grade and, therefore, simplifies the optimization procedure. © (2012) Trans Tech Publications, Switzerland.

World University root node

Applied Mechanics and Materials

Parametric optimization in electrochemical machining of EN-31 steel based on grey relation approach

This work reports the measured spray structure and droplet size distributions of ethanol-gasoline blends for a low-pressure, multi-hole, port fuel injector (PFI). This study presents previously unavailable data for this class of injectors which are widely used in automotive applications. Specifically, gasoline, ethanol and gasoline-ethanol blends containing 10%, 20% and 50% ethanol were studied using laser backlight imaging and particle/droplet image analysis (PDIA) techniques. The fuel mass injected, spray structure and tip penetrations, droplet size distributions and Sauter mean diameter were determined for the blends, at two different injection pressures. Results indicate that the gasoline and ethanol sprays have similar characteristics in terms of spray progression and droplet sizes in spite of the large difference in viscosity. It appears that the complex mode of atomization utilized in these injectors involving interaction of multiple fuel jets is fairly insensitive to the fuel viscosity over a range of values. This result has interesting ramifications for existing gasoline fuel systems which need to handle blends and even pure ethanol, which is one of the renewable fuels of the future. © 2012 Elsevier Ltd. All rights reserved.

Fuel

Spray characterization of gasoline-ethanol blends from a multi-hole port fuel injector

Non-intrusive flow measurements are useful for the understanding of physical processes central to engine combustion and emission performance, such as fuel-air mixing. In the present work, a test rig with maximum optical access is designed and fabricated to study the incylinder flow due to reciprocating piston during compression using particle image velocimetry (PIV) and proper orthogonal decomposition (POD), a technique for investigating turbulent flows. Very few investigations of the incylinder flow using the PIV-POD combination are reported in literature. The effects of the piston configuration and the piston position on the incylinder flow are investigated, for two piston configurations, viz., flat piston and spherical bowl, six piston positions, from the bottom dead centre (BDC) to 150° after BDC, in steps of 30°. PIV measurements are carried out in the vertical plane passing through ports at 600 rpm crank speed. The ensemble-averaged velocity fields obtained from PIV reveal a large scale rotation particularly in the early part of the compression stroke, i.e., from BDC to 90° after BDC (aBDC). In the later part of compression, the flow is observed to be directed towards the cylinder head. POD is applied to the measured instantaneous velocity to study the incylinder turbulent flow. The POD modes show the flow fluctuations due to the effect of turbulence and cycle-to-cycle variations. For the spherical bowl case at 150° aBDC, the share of the fluctuation kinetic energy in the second and higher POD modes is higher than that (a) at any other piston position (b) in the case of flat piston. Thus, the POD analysis of instantaneous velocity measured using PIV, indicates that a spherical bowl is a better choice in terms of turbulence production compared to a flat piston, for use in engines. Copyright © 2012 by the Japan Society of Mechanical Engineers.

Proceedings of the 8th International Conference on Modeling and Diagnostics for Advanced Engine Systems, COMODIA 2012

Diagnostics of incylinder flow during compression using PIV and analysis using proper orthogonal decomposition

Minimum Quantity Lubrication (MQL) technique obtained a significant attention in machining processes to reduce environmental loads caused by usage of conventional cutting fluids. Recently nanofluids are finding an extensive application in the field of mechanical engineering because of their superior lubrication and heat dissipation characteristics. This paper investigates the use of a nanofluid under MQL mode to improve grinding characteristics of Ti-6Al-4V alloy. Taguchi-s experimental design technique has been used in the present investigation and a second order model has been established to predict grinding forces and surface roughness. Different concentrations of water based Al2O3 nanofluids were applied in the grinding operation through MQL setup developed in house and the results have been compared with those of conventional coolant and pure water. Experimental results showed that grinding forces reduced significantly when nano cutting fluid was used even at low concentration of the nano particles and surface finish has been found to improve with higher concentration of the nano particles

World Academy of Science, Engineering and Technology, International Science Index 70, International Journal of Mechanical, Aerospace, Industrial, Mechatronic and Manufacturing Engineering

Application of Nano Cutting Fluid under Minimum Quantity Lubrication (MQL) Technique to Improve Grinding of Ti – 6Al – 4V Alloy

A new nonlinear disturbance observer based tracking control scheme for an underwater manipulator is presented in this paper. This observer overcomes the disadvantages of existing disturbance observers, which are designed or analyzed by the linear system techniques. The performance of the proposed tracking control scheme is demonstrated numerically by the payload compensation and interaction effects compensation for a two degrees of freedom vertical underwater manipulator. © 2012 Springer-Verlag.

Communications in Computer and Information Science

A nonlinear disturbance observer based adaptive control scheme for an underwater manipulator

An indirect adaptive control for an autonomous underwater vehiclemanipulator system (UVMS) based on an extended Kalman filter (EKF) is presented in this paper. This method overcomes the disadvantages of existing disturbance observers and direct adaptive control schemes, which are designed or analyzed by linear system techniques and regressor-based techniques. The proposed control scheme can be applied to UVMS' for various purposes such as payload compensation, interaction effects compensation, underwater current or external disturbance compensation and independent system control. The performance of the proposed controller is demonstrated numerically by the payload compensation and disturbance (underwater current) compensation for an UVMS consisting of a six degrees of freedom (6-DOF) underwater vehicle and a 3-DOF underwater manipulator. Copyright © 2012 by the International Society of Offshore and Polar Engineers (ISOPE).

Proceedings of the International Offshore and Polar Engineering Conference

Indirect adaptive control for autonomous underwater vehicle-manipulator systems

Micro electric discharge machining (μ-EDM) process is being used to machine complex shapes on silicon. In specific, dry-μ-EDM can be used to process assembled or semi assembled silicon products. However, there is lack of investigation on the effect of single pulse discharge machining and its plasma characteristics on silicon. Hence, in this paper we investigate the crater and plasma characteristics of single discharge for various conditions such as different electrode diameters and different energy conditions (fixed voltage with varying capacitance and vice-versa). The plasma temperature and electron density have been calculated by line pair method and modified Saha equation respectively. The values are mapped into the plasma classification plot based on log scale of plasma temperature and electron density and realised that at μ-scale EDM plasma was found to be ideal up to 50 mJ energy and tends to become weakly non-ideal plasma for 98 mJ energy. Also from the influence of energy on plasma characteristics it is understood that electron density also plays a major role along with the plasma temperature. © 2012 Inderscience Enterprises Ltd.

International Journal of Mechatronics and Manufacturing Systems

Investigation of single pulse discharge on silicon: Crater and plasma characteristics

Proceedings of the International Conference on recent advances in {\ldots}

Entrainment in an air jet with Reynolds number of 12,000

Microelectric discharge plasma characteristic using optical emission spectroscopy and its applications are reported. Planar semiconductor as well as metal electrodes as anode and metal cylindrical electrode as a cathode are utilized. Plasma parameters such as plasma temperature and electron density were measured by noncontact optical emission spectroscopy. Plasma temperature has been calculated by line pair method and electron density calculated by modified Saha equation. A comparison between the plasma temperature and electron density of discharge plasma for different electrode combinations have been investigated. Systematic variations with respect to the plasma properties have been noticed for varying energy conditions. Application of electric discharge in surface processing and elemental identification of materials have also been demonstrated. © 2012 Copyright Taylor and Francis Group, LLC.

Materials and Manufacturing Processes

Microelectric discharge plasma: Characterization and applications

We present results of high pressure spray characterization of Straight Vegetable Oils (SVOs) which are potential diesel fuel substitutes. SVO sprays are visualized at high injection pressures (up to 1600 bar) to study their atomization characteristics. Spray structure studies are reported for the first time for Jatropha and Pongamia vegetable oils, under atmospheric conditions. Jatropha and Pongamia SVO sprays are found to be poorly atomized and intact liquid cores are observed even at an injection pressure of 1600 bar. Non-Newtonian behavior of Jatropha and Pongamia oil is shown to be the reason for observed spray structure. © 2012 Elsevier Ltd. All rights reserved.