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

The effect of process parameters on temperature distribution in stationary shoulder friction stir welding (SSFSW) and conventional FSW of AA7010-T6 alloy are studied using a three-dimensional heat conduction analysis. The computed results are validated from experimentally measured results reported in independent literature. The tool torque, traverse force and the mechanical stresses on the FSW tool were evaluated analytically using mechanics based principles. The estimated results showed that the tools used in the SSFSW process were more likely to early failure. © 2019, The Minerals, Metals & Materials Society.

Department of Mechanical Engineering

World University root node

Minerals, Metals and Materials Series

Probing Tool Durability in Stationary Shoulder Friction Stir Welding

Printed circuit boards (PCBs) are composite laminate boards used widely in electronic industry. They facilitate the mounting of electronic components on them as well as to make electrical connections in them. Electronic cooling i.e. removal of heat from electronic components is a challenging task. The heat removal rate from the components also depends upon the thermal conductivity of the board over which it is fixed as it is a critical parameter. The challenge which it poses to the thermal engineers is the determination of thermal conductivity of these boards which are inherently anisotropic in nature. The present study aims to estimate the effective in-plane principal thermal conductivities (kxx and kyy) of anisotropic printed circuit boards by solving an inverse heat conduction problem with measured temperatures as input. Therefore, the present methodology involves three major parts namely the direct or forward problem solution, steady state experiments for obtaining temperature measurements and inverse problem solution. The direct problem involves the solution of heat conduction equation along with appropriate boundary conditions and is solved using commercial CFD package, Ansys Fluent. The experiments are done inside a vacuum chamber and steady state temperature measurements are obtained at 18(9 are used for estimation due to symmetry) preassigned locations. Inverse solution methodology employed using artificial neural network (ANN) is used to solve the inverse problem. The methodology is validated with an in-plane isotropic copper clad board by retrieving its in-plane thermal conductivity successfully. Following this, the inverse methodology is employed to estimate the in-plane thermal conductivities of four PCBs which differ in copper trace width and spacing.

Proceedings of the 24th National and 2nd International ISHMT-ASTFE Heat and {\ldots}

Studies on Influence of Anisotropic Thermal Conductivity of Printed Circuit Board on Heat Transfer During Electronic Cooling

This paper focuses on test procedures under corrupted data.We assume that the observations Zi are mismeasured, due to the presence of measurement errors. Thus, instead of Zi for i = 1, . . ., n, we observe Xi = Zi + √ $\delta$Vi, with an unknown parameter $\delta$ and an unobservable random variable Vi. It is assumed that the random variables Zi are i.i.d., as are the Xi and the Vi. The test procedure aims at deciding between two simple hyptheses pertaining to the density of the variable Zi, namely f0 and g0. In this setting, the density of the Vi is supposed to be known. The procedure which we propose aggregates likelihood ratios for a collection of values of d. A new definition of least-favorable hypotheses for the aggregate family of tests is presented and a relation with the Kullback-Leibler divergence between the sets (f$\delta$)$\delta$ and (g$\delta$)$\delta$ is presented. Finite-sample lower bounds for the power of these tests are presented, both through analytical inequalities and through simulation under the least-favorable hypotheses. Since no optimality holds for the aggregation of likelihood ratio tests, a similar procedure is proposed, replacing the individual likelihood ratio by some divergence based test statistics. It is shown and discussed that the resulting aggregated test may perform better than the aggregate likelihood ratio procedure.

Department of Mathematics

Fulltext

Entropy

Composite tests under corrupted data

Field burning of rice straw as a method of disposal by farmers is a major concern as the smoke and harmful emissions from it causes dangerous levels of pollution. Seven out of ten cities with the poorest air quality in the world are in India and paddy field burning has been cited as one of the main reasons. Hazardous emissions from paddy field burning is combined with greenhouse gas emissions from coal fired power plants and cement manufacturing units, causing severe respiratory illnesses and other fatal health issues. The recent literature indicates an increased interest in rice straw valorisation, possibly in response to the increasing concerns over paddy field burning. However, a systematic study that compiles and compares various rice straw valorisation routes is lacking in the existing literature. This paper provides a comprehensive review of literature on various alternative uses of rice straw in energy and construction industries. Effective use of rice straw as a biomass fuel in energy sector not only reduces the field burning, but also decreases the dependency on non-renewable fossil fuels. Moreover, the proposed utilisation of secondary by-products from rice straw-based energy production in the construction industry can help to attain the goals of resource cascading. The availability of rice straw in major rice producing states of India and the feasibility of establishing rice straw-based power plants are also examined in this study. The potential reduction of harmful emissions from such resource recycling has been determined as per the guidelines issued by the intergovernmental panel on climate change. From the review of literature and the findings of the present study, a sustainable framework has been developed with well-defined cleaner production pathways to create a seamless material flow chain between the agricultural, energy and construction sectors. © 2019 Elsevier Ltd

Department of Civil Engineering

Journal of Cleaner Production

Sustainable alternatives to carbon intensive paddy field burning in India: A framework for cleaner production in agriculture, energy and construction industries

Physics of Fluids

Comment on "modifications to the gradient schemes on unstructured cell centered grids for the accurate determination of gradients near conductivity changes" [Phys. Fluids 31, 047104 (2019)]

We propose a numerical framework to solve thermobuoyant flows in enclosures with large temperature differences under the influence of an applied magnetic field. The solution methodology is based on a staggered/nonstaggered finite volume framework which is modified to solve quasiincompressible flows with heat transfer. The present framework solves a single equation for normal momentum at the face wherein a second-order convection scheme and central differencing is adopted for the convective and viscous term, respectively. An implicit solution approach which is first order accurate in time is employed, and the resulting nonlinear system of equations is solved using the Newton–Krylov approach. The momentum field at the cell centroids is reconstructed using an iterative-defect-correction approach. The energy conservation equation is discretized as in a collocated framework, with a first-order upwind scheme for the convective terms and central differencing for viscous terms, in conjunction with implicit Euler time stepping. Thus the equation is linearized by considering the velocity field at the latest available time step, and the resulting linear system of equations is solved, using an incomplete LU (ILU) preconditioned GMRES solver. The proposed approach is, however, still pressure based, but the energy equation is employed to derive the divergence constraint to be used for solution of the pressure correction equation. This leads to a nonsolenoidal velocity field with a variable coefficient poisson equation, which is also efficiently solved using an ILU preconditioned GMRES solver. Validation studies for small and large temperature differences under the action of imposed magnetic field are carried out to ascertain the applicability of the approach. Finally, investigations of magnetohydrodynamic thermobuoyant flow in an enclosure with a heat obstacle are conducted with a view to understand the effect of magnetic field and heat transfer. © 2019 by Begell House, Inc.

Computational Thermal Sciences

The non-boussinesq algorithm for high temperature gradient thermobuoyant flows with magnetic field

The present work address the problems like low productivity, high manufacturing cost and issues with conventional cooling techniques while machining of 17-4 precipitated hardened stainless steel (PH SS). To overcome these problems, optimization studies have been carried out under cryogenic cooling environment. Cryogenic machining (Liquid nitrogen) is an efficient eco friendly machining technique to satisfy the stringent environmental regulations. In the present work, Taguchi incorporated Gray relational analysis (TGRA) and Taguchi coupled Technique for Order Preference by Similarity to Ideal Solution (T-TOPSIS) optimization techniques have been applied for multi response optimization during rough turning of 17-4 PH SS respectively. The obtained result showed that improved performance was found at the TGRA determined optimum cutting conditions when compared T-TOPSIS technique determined optimum cutting conditions respectively. Furthermore, individual and interaction effect of process parameters on turning performance have been discussed using 3D surface plots. © 2018 Elsevier Ltd

Measurement: Journal of the International Measurement Confederation

Performance improvement of cryogenic turning process during machining of 17-4 PH stainless steel using multi objective optimization techniques

We show that it is possible to construct a quantum absorption refrigerator that provides refrigeration only in the transient regime, by using three interacting qubits, each of which is also interacting with a local heat bath. Though the machine does not provide any effective cooling in the steady state, significant cooling of a qubit can be achieved much before the system reaches its steady state. We also demonstrate a scenario where the temperature of the qubit that has to be cooled, decreases monotonically to its minimum steady-state temperature. This facilitates bypassing of precise time control in cooling. We study the behaviour of the ratio of the heat currents of the machine for both the scenarios. The results remain qualitatively unchanged for different models of thermal baths. We also comment on the temporal behaviour of bipartite and multipartite quantum correlations present in the system, when transient cooling without steady-state cooling takes place. © CopyrightEPLA, 2019.

Department of Physics

Necessarily transient quantum refrigerator

The components built using new generation feature based design and manufacturing process, called laser additive manufacturing (LAM) is inherited with tensile residual stress due to rapid heating and cooling during material processing. Laser shock peening (LSP) is an advanced surface engineering process that imparts beneficial compressive residual stresses into materials yielding longer product life by increasing the resistance to many surface-related failures, such as wear. LSP is widely used by various industries including aerospace, power generation, chemical processing, etc. to increase the life of engineering components. This paper reports LSP of LAM built Inconel 718 and the parametric study is conducted by varying peak laser power and number of shots at three different levels. Optimum laser power and number of shots derived using grey relational analysis is found to be 170 mW and 7, respectively for maximum hardness and minimum depth of profile. The investigation show that LSP changed the surface morphology and mechanical properties of the LAM built structure. The surface investigation using optical profilometer and Vickers micro-hardness shows a maximum profile depth of 10 μm and hardness of 360 HV. Residual stress measurement indicates compressive residual stress of 214.9–307.9 MPa on the LAM sample surface after LSP. The wear studies show an improvement by a factor of 1.70 for LSP treated LAM samples as compared to that of as-built condition. This study unwrap avenues for using LSP as property enhancement post-processing technique LAM fabricated structures with geometrical complexities. © 2019, Korean Society for Precision Engineering.

International Journal of Precision Engineering and Manufacturing

Post-processing of Laser Additive Manufactured Inconel 718 Using Laser Shock Peening

It is known from recent studies that evaporation induces flow around a droplet at atmospheric conditions. This flow is visible even for slowly evaporating liquids like water. In the present study, we investigate the influence of the ambient gas on the evaporating droplet. We observe from the experiments that the rate of evaporation at atmospheric temperature and pressure decreases in a heavier ambient gas. The evaporation-induced flow in these gases for different liquids is measured using particle image velocimetry and found to be very different from each other. However, the width of the disturbed zone around the droplet is seen to be independent of the evaporating liquid and the size of the needle (for the range of needle diameters studied) and only depends on the ambient gas used. © 2019 Author(s).