Journal of Engineering and Technology 2011 1(2):59-64

Cryogenic treatment ("Cryo") is a supplementary process to improve the properties of metals like high carbon high chromium alloy tool steels (D-3) which are increasingly used in manufacturing high-performance cutting tools (dies and punches), blanking and punching tools, extrusion tools, parts of aerospace and automotive industries, etc. The purpose of this study is to investigate the effect of parameters like pulse width, time between two pulses, maximum feed rate, servo reference mean voltage, short pulse time, and wire mechanical tension, on cutting rate (cr) of cryogenic-treated D-3 in wire electrical discharge machining. An L27 orthogonal array has been used to conduct experiments and statistically evaluate the experimental data by analysis of variance (ANOVA). It is seen that cr decreases with increase in pulse width, time between two pulses, and servo reference mean voltage. cr first decreases and then increases with increase in wire mechanical tension. The confirmation experiments have also been conducted to validate the results obtained by Taguchi technique.]]>

Journal of Engineering and Technology 2011 1(2):65-69

This paper presents the numerical analysis of fluid flow in a parallel plate channel having dual triangular prisms in side-by-side arrangement. The computational domain is considered two dimensional. The fluid flow is assumed to be incompressible, steady and laminar with constant thermophysical properties. The computations are performed for a Reynolds number of 100 and blockage ratio (b) of 0.25, where the blockage ratio (b) is the ratio of prism base to the channel height (b = B/H). The unstructured triangular grid is used for the computational domain. The results are compared with the channel having single triangular prism and plane channel. The channel walls are subjected to a constant wall temperature. Unsteady two-dimensional Navier Stokes and energy equations are solved numerically using a control volume method. The SIMPLE discretization algorithm is used for the convective terms in the solution equations. CFD software FLUENT 6.2 is used to simulate the fluid flow and temperature field. A preprocessor GAMBIT is used to generate the required mesh for the solver. Results illustrate that the Nusselt numbers on the channel walls are strongly modified by the vortices induced by the presence of triangular prisms. In the presence of triangular prisms, the average Nusselt number is 8.5% more as compared to plane channel and 4.5% as compared to channel having single prism at the same Reynolds number and blockage ratio.]]>

Journal of Engineering and Technology 2011 1(2):70-73

To improve the global throughput of computational grid, effective and efficient load balancing algorithms are fundamentally important. A computational grid differs from traditional high-performance computing system in the heterogeneity of computing nodes, as well as the communication links that connect the different nodes together. In this paper, we propose a resource queue length based solution to the grid load balancing problem. The proposed algorithm will balance the load in the grid based on the queue length of each resource and transfer the job to the resource having minimum queue length. The simulation results show that our algorithm can achieve a better load balancing performance than its counterpart provided in simulation.]]>

Journal of Engineering and Technology 2011 1(2):74-82

The present work describes the fluid-film pressure (p) distributions, fluid-film thickness (h) profiles and fluid-film temperature (Tf) distributions of orifice-compensated symmetric hole-entry hybrid journal bearing considering the combined influence of rise in temperature and non-Newtonian behavior of the lubricant. The required governing equations have been solved using the finite element method and a suitable iterative technique. The non-Newtonian lubricant has been assumed to follow the cubic shear stress law. The computed results illustrate that variation of viscosity due to rise in temperature and non-Newtonian behavior of the lubricant affects the performance of symmetric hole-entry hybrid journal bearing system quite significantly.]]>

Journal of Engineering and Technology 2011 1(2):83-87

Frequency analysis plays a vital role in the applications like cryptanalysis, steganalysis, system identification, controller tuning, speech recognition, noise filters, etc. Discrete Fourier transform (DFT) is a principal mathematical method for the frequency analysis. The way of splitting the DFT gives out various fast algorithms. In this paper, we present the implementation of two fast algorithms for the DFT for evaluating their performance. One of them is the popular radix-2 Cooley-Tukey fast Fourier transform (FFT) algorithm and the other one is the Grigoryan FFT based on the splitting by the paired transform. We evaluate the performance of these algorithms by implementing them on the TMS320C5416 DSP and also on the Virtex-II FPGAs. Finally, we show that the paired-transform-based algorithm of the FFT is faster than the radix-2 FFT; consequently, it is useful for higher sampling rates. We also discuss the performances of TMS DSP and Xilinx FPGAs and tradeoffs.]]>

Journal of Engineering and Technology 2011 1(2):88-93

High-speed steel (HSS) tools are the most commonly used tools in small and medium-scale industry. So far, a few studies have been carried out pertaining to the life of HSS single point cutting tool. Studies on cryogenically treated (CT) cutting tools show microstructural changes in the material that can influence the life of the tools significantly. This paper primarily reports performance of CT HSS tools as compared to untreated (UT) HSS tools. The results show that CT HSS tools exhibit better performance based on tool wear, surface roughness of the work specimen, and power consumption during operation than the UT HSS tools.]]>

Journal of Engineering and Technology 2011 1(2):94-99

An inverted three-lobe pressure dam bearing which is produced by cutting a pressure dams on the upper lobe and two relief-tracks on the lower two lobes of an ordinary inverted three-lobe bearing is found to be more stable than an inverted three-lobe bearing. In this paper an inverted three-lobe pressure dam bearing supporting rigid and flexible rotors is analytically investigated to determine its performance when L/D ratio is varied in the range 0.8-1.5. The static and dynamic characteristics are studied at various L/D ratios. The results show that the stability of an inverted three-lobe pressure dam bearing increases with decrease in L/D ratios both for rigid as well as flexible rotors.]]>

Journal of Engineering and Technology 2011 1(2):100-106

A study was undertaken to analyze metal inert gas (MIG) welding of aluminum plates keeping in mind the potential capabilities of MIG welding process and selecting aluminum as base metal due to its increased demand in aerospace and automotive industries. Primary welding parameters, viz. welding current, arc voltage, welding speed, were identified and investigations were carried out to study their effect on the tensile strength and yield strength of the weldments by using 2 3 factorial design. A brief introduction to MIG welding processes is included, along with the literature review of research in the field of MIG welding of aluminum.]]>

Journal of Engineering and Technology 2011 1(2):107-112

Six Sigma within small- and medium-sized enterprises (SMEs) is rapidly emerging as the new wave of change in Six Sigma. The methodology adopted is Define, Measure, Analyze, Improve, and Control (DMAIC) of Six Sigma which had been mostly successful so far in large-scale industries. The methodology has been applied to reduce the rejection rate of the engine mounting bracket (EMB) by reducing defects inherent in the processes. The application of Six Sigma project recommendation brought up the process sigma level to 5.24 from 1.64 by reduction in EMB hole diameter variation in the process of machining after die casting. This increase in the sigma level is equivalent to a monitory saving of Rs. 0.260 million per annum which is a noteworthy figure for an industry of such level. This paper provides documented evidence of Six Sigma implementation in a die casting manufacturing unit which has been taken as a representative of a small- and medium-size industry.]]>

Journal of Engineering and Technology 2011 1(2):113-119

In any industry, the three top operating expenses are often found to be on energy, labor and materials. If one were to find out the potential cost savings in each of the components, energy would invariably emerge at the top, and thus energy management function constitutes a strategic area for cost reduction. This paper discusses the common aspects of electrical energy management in small- and medium-sized industries. It contains the findings and the analysis of the results obtained from the electrical energy audit program employed in an industrial unit, Isolloyds Engineering Technologies Ltd. (Baddi, Himachal Pradesh). The electrical energy audit was carried out under four major heads: (i) lighting audit, (ii) Heating Ventilation Air Conditioning (HVAC) audit, (iii) power load audit (motors, melter, etc.), and (iv) harmonic analysis. Readings were taken under these heads and analyzed to find the scope of energy conservation opportunities in the selected test case industrial unit.]]>