http://nopr.niscair.res.in/handle/123456789/3302 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/3316 Title: Optimization of high speed turning parameters of superalloy Inconel 718 material using Taguchi technique <br/> <br/>Authors: Thakur, Dinesh; Ramamoorthy, B; Vijayaraghavan, L <br/> <br/>Abstract: Superalloy, Inconel 718 is widely used in sophisticated applications due to its unique properties desired for the engineering applications. Due to its peculiar characteristics machining of Superalloy Inconel 718 is difficult and costly. The present work is an attempt to make use of Taguchi optimization technique to optimize cutting parameters during high speed turning of Inconel 718 using tungsten carbide cutting tool. Taguchi method is a powerful design of experiments (DOE) tool for engineering optimization of a process. It is an important tool to identify the critical parameters and predict optimal settings for each process parameter. Analysis of variance (ANOVA) is used to study the effect of process parameters and establish correlation among the cutting speed, feed and depth of cut with respect to the major machinability factor, cutting forces such as cutting force and feed force. Validations of the modeled equations are proved to be well within the agreement with the experimental data. <br/> <br/>Page(s): 44-50 http://nopr.niscair.res.in/handle/123456789/3315 Title: Failure analysis of a spring for a fuel pump bracket assembly <br/> <br/>Authors: Roy, Himadri; Ghosh, Debashis; Sahoo, Tapas; Shukla, Awadhesh <br/> <br/>Abstract: This investigation is primarily aimed to examine the premature failure of a spring used in a fuel pump bracket assembly. Preliminary visual examinations along with detailed SEM studies are made on the damaged surface and fracture surface of the failed spring. In addition, microstructural investigations along with hardness measurements are carried out to understand the reason for the premature failure. Finally, it is concluded that improper heat treatment of the spring material is responsible for failure. <br/> <br/>Page(s): 33-36 http://nopr.niscair.res.in/handle/123456789/3314 Title: Experimental study of recirculating flows induced by vane swirler <br/> <br/>Authors: Raj, R Thundil Karuppa; Ganesan, V <br/> <br/>Abstract: The core objective of this study is to present the details of the experimental procedure and measurements made in an axisymmetric swirler model. The flow through 8 blade 30º vane swirler is studied experimentally. An overlap angle of 30º is provided between the vanes for the proper guidance of the flow through swirler. A hemi spherical bluff body is attached to the hub in order to overcome the inlet flow field distortion. A 5 mm diameter five-hole pitot sphere of cobra type has been used along with electronic digital manometers for the measurements. A computer aided traversing mechanism supported with Streamware software automatically controls the traversing of the probe. The recirculation velocities at the center core and corner regions are well captured with the five-hole probe. Five-hole pitot probe measurements along the entire length of the model at different stations, allow the determination of axial mean velocity component and pressure field parameters, which provide comprehensive information to aid and understand such complex recirculation flows. Flow field characteristics downstream of the swirler at different axial locations are examined in detail. The recirculation length and width are found to be strongly dependent on the amount of turbulence created by the vane swirler. <br/> <br/>Page(s): 14-22 http://nopr.niscair.res.in/handle/123456789/3312 Title: Relationship between thermal stability and molecular structure of polynitro arenes <br/> <br/>Authors: Keshavarz, M H; Pouretedal, H R; Semnani, A <br/> <br/>Abstract: A simple relationship has been derived to predict thermal stability of CHNO polynitro arenes on the basis of onsets of thermal decomposition, which can be obtained by means of non-isothermal differential thermal analysis (DTA). The model is optimized using a set of 12 polynitro arenes so that R-squared value or the coefficient of determination of the new correlation is 0.95. The new correlation has also been applied to 6 polynitro arenes explosives from a variety of chemical families in order to assess the predictive capability of new method. Predicted results are close to the measured values for all of tested polynitro arenes on the basis DTA. <br/> <br/>Page(s): 61-64