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.

&nbsp;

IIT Palakkad

The present numerical analysis aims at studying the effect of changes in profile of van on aero-acoustic noise and aerodynamic drag. The numerical analysis is carried out using commercial CFD software, ANSYS Fluent, with k-epsilon & Large Eddy Simulation turbulence models. In present study five models of truck are analysed, including baseline model at different Reynolds numbers, namely 0.391, 0.415 and 0.457 million. In order to reduce the aero-acoustic noise, various profile modifications have been adapted on existing van model by adding a top and bottom diffuser at the rear of the truck. The comparison has been done with respect to coefficient of drag, coefficient of pressure, pressure contours for all four cases. It is observed from the simulation results among different modifications of truck, adding a top and bottom diffuser of 15 degrees at the rear end of truck gives the maximum reduction in aero-acoustic noise up to 9.4% and aerodynamic drag reduction of 3.8 % as compared to baseline model, at a speed of 81 km/h. © 2019 SAE International. All Rights Reserved.

Department of Electrical Engineering

World University root node

SAE Technical Papers

Attenuation of Aeroacoustic Noise of a Typical Van Using Passive Devices through CFD Simulation

We study the problem of designing error-correcting codes over channels with burst and random erasures, when a strict decoding delay constraint τ is in place. Badr et al. introduced a channel model wherein for any sliding-window of width w, at most one of the following erasures patterns are permissible; (i) a burst erasure of length ≤ b or (ii) a total of ≤ a random erasures. We present a rate-optimal code construction under this model, which covers all feasible channel and delay parameters. In contrast to existing rate-optimal code families which require a field-size at least as large as O\left( {\binom {\tau} {a} } \right), our construction needs a field-size quadratic in the decoding delay constraint. For some parameters, the construction can be over linear field-size. © 2019 IEEE.

Department of Data Science

IEEE International Symposium on Information Theory - Proceedings

A Quadratic Field-Size Rate-Optimal Streaming Code for Channels with Burst and Random Erasures

Scratch tests are useful techniques to gain insight into the material removal mechanism of abrasive machining processes. In most of the scratch tests, uncut chip thickness value is either constant or varies from zero to maximum. However, in abrasive machining processes, uncut chip thickness value ranges from either zero to maximum or vice versa. Moreover, regular scratch tests are conducted at very low speeds, in which either the indenter or the workpiece is stationary. Because of these limitations, the knowledge obtained from the existing scratch test results is not valid for most of the abrasive processes. Hence, in this paper, the influence of chip thickness variation, speed ratio, and depth of cut on the pile-up behaviour of AISI 1015 steel and 2017A-T4 aluminium alloy surfaces were investigated. The workpiece having the comparable thermal diffusivity value with the grit has shown a significant difference in its pile-up behaviour. Through a better understanding of chip thickness influence on pile-up ratio, a mathematical model was developed for kinematic simulations. Using the developed model, kinematic simulations were done to visualise the scratch surface topography and material pile-up by considering the grit trajectory path and chip thickness variation. Finally, simulated surfaces were compared with the experimental results to show the proposed method applicability. © 2019, Springer-Verlag London Ltd., part of Springer Nature.

Department of Mechanical Engineering

Fulltext

International Journal of Advanced Manufacturing Technology

Experimental investigations and kinematic simulation of single grit scratched surfaces considering pile-up behaviour: grinding perspective

This article presents a method to characterize electroless plated micro grinding tools using an optical measuring device. Abbott Firestone curve characteristics, such as height distribution, void volume, and material volume obtained from topography measurements, were used to define “volume ratio.” This parameter distinguishes the micro grinding tools according to their planar grit density. As a result, micro grinding tools can be classified in a manner similar to conventional grinding wheels. © 2019 Elsevier Ltd

Optics and Lasers in Engineering

Characterization of micro grinding tools using optical profilometry

The present work focusses on improving the surface wear resistance of commerical pure copper by reinforcing tungsten particles through friction stir processing. Particularly this work adopts Taguchi’s experimental design to achieve minimum wear rate for Copper-Tungsten surface composite by optimizing the process parameters. The rotational and traverse speeds of tool and volume fraction of reinforcement (i.e. tungsten) are the chosen parameters for minimizing the wear rate. Taguchi L9 orthogonal array was used to design the experiments. The surfaces of the processed specimens were investigated by optical microscopy for the distribution of tungsten particles and sliding wear behavior was studied by conducting pin-on-disc method. It was observed from the optical micrographs that the reinforcement evenly dispersed in the processed zone. The measured hardness was 85% higher than the base metal for the specimen exhibited minimum wear rate. The effects of all three parameters on wear rate were studied. The minimum wear rate was achieved by using rotational and traverse speeds of tool, 1200rpm and 60mm/min, respectively. The amount of reinforcement required to achieve maximum wear resistance was 10%. Variance analysis showed that amount of reinforcement played a key role in determining the properties than the other parameters. © 2019 Trans Tech Publications Ltd, Switzerland.

Materials Science Forum

Optimization of friction stir processing parameters for the development of cu-w surface composite

We present a suite of seven 3D supernova simulations of non-rotating low-mass progenitors using multigroup neutrino transport. Our simulations cover single star progenitors with zero-age main-sequence masses between 9.6 and 12.5 M and (ultra)stripped-envelope progenitors with initial helium core masses between 2.8 and 3.5 M. We find explosion energies between 0.1 and 0.4 Bethe, which are still rising by the end of the simulations. Although less energetic than typical events, our models are compatible with observations of less energetic explosions of low-mass progenitors. In six of our models, the mass outflow rate already exceeds the accretion rate on to the proto-neutron star, and the mass and angular momentum of the compact remnant have closely approached their final value, barring the possibility of later fallback. While the proto-neutron star is still accelerated by the gravitational tug of the asymmetric ejecta, the acceleration can be extrapolated to obtain estimates for the final kick velocity. We obtain gravitational neutron star masses between 1.22 and 1.44 M, kick velocities between 11 and 695 km s−1, and spin periods from 20 ms to 2.7 s, which suggest that typical neutron star birth properties can be naturally obtained in the neutrino-driven paradigm. We find a loose correlation between the explosion energy and the kick velocity. There is no indication of spin-kick alignment, but a correlation between the kick velocity and the neutron star angular momentum, which needs to be investigated further as a potential point of tension between models and observations. © 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.

Department of Physics

Monthly Notices of the Royal Astronomical Society

Three-dimensional simulations of neutrino-driven core-collapse supernovae from low-mass single and binary star progenitors

Management of bridge assets requires a life-cycle approach that balances design and construction of new bridges, and maintenance of existing bridge stock. There has been a growing need for inspection, maintenance, repair, and strengthening of existing bridge structures due to aging transportation infrastructure. Condition assessment of post-tensioning systems could allow bridge owners to take timely, proactive actions to mitigate or prevent further deterioration and unanticipated failure. An experimental study to evaluate various nondestructive evaluation (NDE) techniques for the condition assessment of grout defects in external post-tensioning systems is presented. To evaluate the NDE technologies, a full-scale post-tensioned girder specimen was constructed at the Texas A&M University RELLIS Campus. Several grout defects including voids, water infiltration, and compromised grout were fabricated and placed in the specimen for the evaluation of the NDE methods. The research team, in collaboration with several industry partners, used various NDE technologies, such as sounding, impact echo, low-frequency ultrasound, ground-penetrating radar, infrared thermography, and electrical capacitance tomography, to evaluate the grout condition of the external tendons of the post-tensioned girder specimen. Comparison of the test results with the actual defects revealed the performance of each method in detecting the location and the severity of the various grout defects in the external tendons of the post-tensioning system. © 2018 American Society of Civil Engineers.

Department of Civil Engineering

Journal of Structural Engineering (United States)

Nondestructive Evaluation of External Post-Tensioning Systems to Detect Grout Defects

Nondestructive evaluation (NDE) can provide invaluable information about the condition of tendons in post-Tensioned and cable-stayed bridges, which can facilitate preventative actions to mitigate further deterioration. To date, the use of nondestructive testing methods for routine maintenance of bridges has been relatively low, partly due to limitations of available technologies but mainly owing to a lack of know-how regarding existing NDE techniques and guidelines. This study aims to develop guidelines to assist bridge owners and engineers in selecting the most appropriate NDE method or combination of methods for assessing the condition of in-service post-Tensioning and stay cable systems. An extensive experimental study is conducted on a full-scale post-Tensioned girder specimen and four large-scale stay cable specimens to evaluate the performance of various NDE methods in detecting location and severity of numerous strand and grout defects. Decision metrics are developed considering multiple criteria such as precision, accuracy, ease of use, inspection requirements, and cost. The decision metrics are intended to facilitate selecting the most appropriate NDE method for assessing a particular defect condition. Overall scores for the tested NDE methods in identifying various defect conditions in different parts of the post-Tensioning and stay cable systems are calculated using a weighted sum model. These scores are used to develop a list of ranked NDE methods for evaluating a particular defect condition within a specific location and for a specific duct material. © 2019 American Society of Civil Engineers.

Journal of Infrastructure Systems

Systematic Assessment of Nondestructive Evaluation Techniques for Post-Tensioning and Stay Cable Systems

Runtime verification employs dedicated hardware or software monitors to check whether program properties hold at runtime. However, these monitors often incur high area and performance overheads depending on whether they are implemented in hardware or software. In this work, we propose DHOOM, an architectural framework for runtime monitoring of program assertions, which exploits the combination of a reconfigurable fabric present alongside a processor core with the vestigial on-chip Design-for-Debug hardware. This combination of hardware features allows DHOOM to minimize the overall performance overhead of runtime verification, even when subject to a given area constraint. We present an algorithm for dynamically selecting an effective subset of assertion monitors that can be accommodated in the available programmable fabric, while instrumenting the remaining assertions in software. We show that our proposed strategy, while respecting area constraints, reduces the performance overhead of runtime verification by up to 32% when compared with a baseline of software-only monitors. © 2019 Association for Computing Machinery.

Department of Computer Science and Engineering

Proceedings - Design Automation Conference

DHOOM: Reusing design-for-debug hardware for online monitoring

We present high-resolution (1024 3) simulations of super-/hypersonic isothermal hydrodynamic turbulence inside an interstellar molecular cloud (resolving scales of typically 20-100 au), including a multidisperse population of dust grains, i.e. a range of grain sizes is considered. Due to inertia, large grains (typical radius a ≳ 1.0μm) will decouple from the gas flow, while small grains (al∼ 0.1μm) will tend to better trace the motions of the gas. We note that simulations with purely solenoidal forcing show somewhat more pronounced decoupling and less clustering compared to simulations with purely compressive forcing. Overall, small and large grains tend to cluster, while intermediate-size grains show essentially a random isotropic distribution. As a consequence of increased clustering, the grain-grain interaction rate is locally elevated; but since small and large grains are often not spatially correlated, it is unclear what effect this clustering would have on the coagulation rate. Due to spatial separation of dust and gas, a diffuse upper limit to the grain sizes obtained by condensational growth is also expected, since large (decoupled) grains are not necessarily located where the growth species in the molecular gas is. © 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.