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.

&nbsp;

IIT Palakkad

The hot deformation behavior of sintered Al-4%B4C composites was studied in this work. The main aim of this work is to estimate the effect of initial relative density (IRD), deformation temperature and strain rate on the hot deformation behavior and development of constitutive equations for predicting the hot deformation behavior. For this purpose, upsetting was performed in a hydraulic press for obtaining true stress-true strain curve data of sintered Al-4%B4C composites. The tests were carried out at different IRDes of 80%, 85% and 90% for various temperatures of 573 K, 673 K and 773 K and strain rates of 0.1 s-1, 0.2 s-1 and 0.3 s-1. The test reveals that the effect of IRD, deformation temperature and strain rate on flow stress curves is significant. The constitutive equations have been developed for predicting the flow stress behavior during the hot upsetting of sintered Al-4%B4C composite and it's validated with experiments. In addition, the required activation energies (Q) of sintered Al-4%B4C composites during the hot upsetting were calculated for various IRDes of 80%, 85%, and 90% was 161.06, 172.28 and181.05 KJ/mol, respectively, which is higher than the value of pure aluminum (144.3 KJ mol-1). © 2020 IOP Publishing Ltd.

World University root node

Fulltext

Materials Research Express

Modeling flow behavior of sintered Al-4%B4C composite during high-temperature upsetting

Preprints of the National Meeting of Japan Welding Society

Modeling of residual stresses in stationary shoulder friction stir welding

Multi-port gas burners find applications in various industrial and domestic heating appliances. The multiple flame jets of the burners provide higher rate of heat transfer with uniform heat flux over a large area of the target surface. An extensive contribution to the design and development of energy efficient and clean combustion gas burners is reported by the scientific community. The involvement of combustion apart from the heat transfer makes the physical understanding more complex as compared to other heating methods. One of the most interesting things is that the combustion and the heat transfer phenomenon are associated with one another and the independent characterization of each will be unproductive. Present study investigates the thermal characterization of self-aspirating radial-type domestic gas stove burners. The heat transfer characteristics are studied for varied inner port swirl angles. An alternate methodology is suggested to evaluate the thermal performance of burners which gives more technical insights in comparison with conventional water loading test. The thermal efficiency from the conventional water loading method and the presented alternate method matches within ±2%. Among all swirl angles of burner ports, the inner port swirl angle of 10° produced higher Nusselt number and thermal efficiency. The efficiency is found to be increased by 7% by a simultaneous reduction in the loading height by 10 mm and by providing an inner swirl angle of 10°. © 2019 Elsevier Ltd

Applied Thermal Engineering

Thermal investigations on self-aspirating type radial flow burners with induced swirl

Thermally efficient gas burners can be designed by optimising the parameters associated with combustion and heat transfer mechanisms. The current study presents the thermal analysis of the premixed methane-air flame jets of circular tube gas burner impinging on a target surface. The effect of flame jet parameters such as mixture Reynolds number, equivalence ratio and burner to target surface spacing on heat transfer characteristics is investigated. The thermal performance is quantified in terms of thermal efficiency. The lean and stoichiometric mixtures release maximum amount of thermal energy. However, in lean flames, a part of the energy released is used for rising the temperature of excess air. Though the combustion is incomplete for fuel rich flames, higher heat transfer is achieved because of higher flame height. The optimal thermal performance is observed when the mixture is near stoichiometric and the burner is spaced from the target surface such that the premixed cone tip just touches the surface. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.

Heat and Mass Transfer/Waerme- und Stoffuebertragung

Impinging premixed methane-air flame jet of tube burner: thermal performance analysis for varied equivalence ratios

A novel diffuse interface immersed boundary (IB) approach in the finite volume framework is developed for non-Boussinesq flows with heat transfer. These flows are characterized by variable density, large temperature differences, nonzero velocity divergence, and low Mach numbers. The present IB methodology assumes that the solid body immersed in the domain is filled with a "virtual" fluid and constructs a unified momentum equation that is solved everywhere in the domain. The unified momentum equation is obtained as a convex combination of the Navier-Stokes equation and the no-slip boundary condition employing the solid volume fraction. The hydrodynamic pressure (p) that drives the flow is obtained by the solution of a variable density Poisson equation that is constructed by assuming that the velocity field inside the solid always remains solenoidal although the velocity divergence is nonzero in the fluid domain. The unified Poisson equation is also solved everywhere in the domain and has source terms that depend on the solid volume fraction, temperature gradients, and the spatially invariant thermodynamic pressure (P) that vanish in the Boussinesq limit. The thermodynamic pressure in closed domains follows from the principle of global mass conservation and is used to determine the density field everywhere in the domain except inside the solid where the density remains constant. Numerical simulations are carried out for natural and mixed convective flows in enclosures with stationary and moving heated bodies encompassing both Boussinesq and strongly non-Boussinesq flow regimes. The results of these investigations show that the local Nusselt number distribution over the body surface is oscillatory particularly when grid lines are not aligned with the surface of the body. However, the proposed approach can reasonably accurately compute the average heat transfer in both Boussinesq and non-Boussinesq flows. Investigations show that the heat transfer is significantly enhanced in the non-Boussinesq regime as compared to the Boussinesq regime. A comparison of results from the present approach with those obtained using a body-fitted finite volume solver for stationary bodies demonstrates that the proposed IB approach can compute the flow dynamics quite accurately even on Cartesian meshes that do not conform to the geometry. The IB approach presented herein is a generic approach for quasi-incompressible flows and may be applied to other low Mach number flows such as mixing and reacting flows. © 2019 Author(s).

Physics of Fluids

Diffuse interface immersed boundary method for low Mach number flows with heat transfer in enclosures

Currently, metal cutting industries are pushed for eco-friendly techniques to reach the severe environmental regulations. In this context, different environment sustainable machining techniques have been investigated along with the cutting conditions. The current work focuses on the culling of optimum cutting conditions in turning of 17-4 precipitation hardened stainless steel (PH SS) using Taguchi optimization method. In turning process, cutting speed (v), feed rate (f), depth of cut (d) and cooling environment (cryogenic, MQL and dry) were selected as controllable process parameters and surface roughness (Ra), tool flank wear (Vb) were considered as performance evaluation characteristics. Taguchi L9 orthogonal array (OA) experimental design plan was consider for carrying out the experiments. From the conformation tests, it was found that the Taguchi analysis determined optimum process parameters significantly improved the turning performance during machining of 17-4 PH SS. From ANOVA results, it was seen that the turning performance in terms of Ra and Vb were greatly influenced by cutting speed. Furthermore, regression models were developed for predicting the Ra as well as Vb respectively. It was observed that cryogenic coolants overcome the health and environment problems which can lead to an absolute sustainable machining technique. It is recommended that metal cutting industries could used these optimum cutting conditions to reduced the material waste and increase the productivity while machining of 17-4 PH SS. © 2018 Elsevier Ltd

Measurement: Journal of the International Measurement Confederation

Modeling and optimization of sustainable manufacturing process in machining of 17-4 PH stainless steel

Laser dimple texturing has been a surge in the surface to surface contact applications like the cutting tool/workpiece interaction, piston-cylinder assembly, bearings, prosthetic hip & knee joints, blanking punch- die assembly, etc. to control the friction and wear between the interactions. In this article, the first part presented about a broad literature review on an effect of dimple texture in various industrial applications like bio-implant components and cutting tools. In the second part, detailed information has discussed on a process of laser dimple texturing and influence of laser process parameters such as laser wavelength, laser energy, number of pulses, pulse duration and focal distance on dimple geometry. The third part describes a comprehensive literature review on challenges/limitations of laser dimple texturing process like heat affected zone, tensile residual stresses, bulges around the dimple, etc. Finally, in the fourth part, proper attention has given on recent developments like laser shock peen texturing, laser texturing under water and post-processing techniques to overcome the limitations of laser surface texturing process. © 2019, © 2019 Engineers Australia.

Australian Journal of Mechanical Engineering

Laser dimple texturing–applications, process, challenges, and recent developments: a review

The demand for miniaturized products and functionalized parts is increasing, and many such products are made of hard and brittle materials machined by abrasive processes. The first part of this keynote paper is dedicated to a discussion of micro parts and micro structures machined – at least in part – by abrasive processes, followed by a discussion of the associated abrasive processes. The strengths and limitations of these processes, among which include dicing, micro grinding, micro abrasive blasting, and vibration and magnet field assisted finishing are discussed. The paper concludes with a discussion of future trends in the field. © 2019

CIRP Annals

Abrasive processes for micro parts and structures

The use of crude oil as a backup fuel in gas turbines remains an economical option for power plants in petroleum-rich countries like Saudi Arabia. However, operating gas turbines with crude oil can corrode their Hot-Gas-Path (HGP) components due to the formation of vanadium oxides and alkali metal vanadates, when preventative measures are not employed. While the pre-combustion treatment of crude oil fuel is effective at reducing the content of sodium (Na) and potassium (K) in the fuel and, therefore, their resulting combustion products, any pre-combustion removal of vanadium has remained unviable on a commercial scale. Typically, a best practice limit of 0.5 ppmw vanadium is imposed on liquid fuels when inhibitors are not employed, and the total alkali content is limited to 1.0 ppmw. To evaluate the effects of incremental exceedances of such limits on the structural materials and coatings of gas turbines, a high-pressure hot-corrosion test rig was built at King Abdullah University of Science and Technology (KAUST). Arabian Extra Light (AXL) crude oil with a vanadium content of up to 2 ppm was chosen as the test fuel. This burner rig was designed to accommodate high temperatures (~1173 K/ 900 °C) and the combustion of unrefined crude oils at an elevated pressure of up to 15 bar. Highly reduced flow velocities (~1 m/s) were employed to deconvolute erosional effects from corrosion. This experiment exposed the tested materials to combustion products under these conditions for extended periods (up to 500 hours). The development of the rig included several design iterations and changes to the configuration of various sub-systems, owing to some challenges in maintaining stable combustion at low flow rates, management of coke/ash formation from the burning of crude oil, and adequate control over the pressure and temperature during extended experimental campaigns. The present publication summarizes the design and commissioning of this high-pressure hot-corrosion rig facility, and the successful demonstration of several long duration (400+ hour) experimental runs with AXL crude oil, where the environment of the sample section with test coupons was maintained at 5.5 bar and 1173 K. The pressure and temperature inside the sample section of the rig were continuously monitored. The batch of material coupons was removed from the sample section after the runs and sent for corrosion analysis. Deposits resulting from the AXL combustion and fouling were collected from several sections of the rig for analytical analysis. The fuel wash procedure, the design of components in the burner rig, and best practices of operation were also documented. Copyright © 2019 ASME.

Proceedings of the ASME Turbo Expo

Development of a high-pressure hot-corrosion burner rig for testing structural materials following long exposures to Arabian extra light crude oil combustion products