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Sterling, VA, United States

Cyient, formerly Infotech Enterprises is a company focussed on engineering, networks and operations. It has 12,000+ employees across 38 global locations as of March 2014. The company features among the top 30 outsourcing companies in the world. On 15 January 2010, Daxcon was acquired by Infotech Enterprises America Inc, a wholly owned subsidiary of Infotech Enterprises Limited, India.On May 7, 2014, Cyient Limited, formerly known as Infotech Enterprises Limited, announced its new name is official based on approval from a shareholders’ vote. The process of determining the new identity, bearing connotations to the words client and science, while ient referencing Infotech Enterprises, involved various brand specialists and the new name was tested in 17 languages. Wikipedia.

Raghavan K.S.,InfoTech Enterprises
ASME 2013 Gas Turbine India Conference, GTINDIA 2013 | Year: 2013

ASME's Boiler and Pressure Vessel Codes have a history of over one hundred years. The codes have been evolving over time with continuous revisions, improvements and refinements. A major milestone has been the incorporation of "Design by Analysis (DBA)" guidelines about fifty years back (for instance Sec. VIII, Division 2). These were introduced as it was recognized that the prevailing Design by Rules (Section VIII, Division 1) tended to be somewhat over-conservative. The essence of DBA guidelines consists of evaluating the elastic stresses at critical locations and checking the same against the allowable. The allowable happen to functions of the nature of stress distribution and the nature of load. A given stress could be of membrane, bending or peak category and also be either primary or secondary. At the time of appearance of the DBA guidelines, the state of the art of stress analysis was not well advanced and the finite element method was just getting developed. As of today, however, the finite element method has reached a high level of maturity and is very widely used. The latest edition (2010) has recognized this and it contains modeling and post-processing guidelines applicable to FE analysis. This edition also recommends the use of one of three possible approaches. The first is the elastic analysis and classification and categorization of stresses with guidelines regarding how to deal with two- and three- dimensional situations. The other two options are provided to take care of situations wherein the categorization process may lead to either uncertainty or ambiguity. These involve nonlinear analysis either by way of Limit-Load method or Elastic-Plastic Stress Analysis. In either approach the analyst will look for the loads at which there is an onset of gross plastic flow. In the present paper an attempt is made to evaluate the latest DBA guidelines from design application point of view. The purpose is to assess the limitations of the elastic analysis approach. Studies are undertaken to focus typically on the following aspects: 1. Two dimensional problems involving symmetry or axisymmetry. There are situations in which the "bending" stresses are liable to be misinterpreted. 2. Three dimensional problems with emphasis on the assessment of bending stress as categorization in 3D situations is a real challenge 3. General situations involving the secondary stresses. The allowable stress limit for secondary stress is somewhat arbitrary and perhaps very conservative. The studies tend to suggest that the nonlinear route is to be adopted as it is reliable and accounts for many uncertainties associated with the elastic approach. Copyright © 2013 by ASME. Source

This paper is an analytical study of entropy generation in the laminar flow of nanofluids in a circular tube. The tube is immersed in an isothermal external fluid - which is the most general thermal boundary condition but has not been studied in much detail in literature. Two nanofluids, namely - water-Al2O3 and ethylene glycol-Al2O3 have been chosen for this study. The effects of the external Biot number, non-dimensional temperature difference and volume fraction on the entropy generation characteristics of the flow have been shown through graphs and the physical reasoning behind the observed trends has been discussed threadbare. It is shown that the addition of nanoparticles is beneficial only at smaller Reynolds number and for less viscous base fluids. Most importantly, it is proved that the entropy generated in the case of a tube immersed in an isothermal external fluid is bounded by those for uniform heat flux and uniform wall temperature boundary conditions. © 2015 Elsevier Ltd. Source

This study concerns the heat transfer and entropy generation characteristics of viscoelastic fluid flow modeled by the exponential formulation of simplified Phan-Thien-Tanner (s-PTT) model. This is the first such study in literature of thermal behavior of viscoelastic fluids modeled by the exponential formulation of s-PTT model. The flow between two parallel plates is laminar, hydrodynamically and thermally fully developed, viscous dissipative and subject to uniform heat flux on the walls. The slip velocity boundary condition is imposed on the fluid-solid interface and the slip is captured by three slip laws, namely, Navier's non-linear slip law, Hatzikiriakos slip law, and asymptotic slip law. The governing equations have been solved analytically. Closed form solutions for the velocity distribution have been derived while the temperature distribution is presented in terms of an infinite but convergent series. The results pertaining to the three slip laws have been presented in detail. Finally, a comparison has been made between the results for exponential formulation and those for the linear formulation of the s-PTT model. The comparison shows that results for linear formulation deviate significantly from those for exponential formulation and thus the accuracy of the exponential formulation justifies the extra mathematical complexity which it entails. © 2015 Elsevier Ltd. All rights reserved. Source

Wang C.-Z.,Aerojet Rocketdyne | Mathiyalagan S.P.,InfoTech Enterprises | Glahn J.A.,Aerojet Rocketdyne | Cloud D.F.,Aerojet Rocketdyne
Journal of Turbomachinery | Year: 2014

Numerical simulations of turbine rim seal experiments are conducted with a time-dependent, 360 deg computational fluid dynamics (CFD) model of the complete turbine stage with a rim seal and cavity to increase understanding of the rim seal ingestion physics. The turbine stage has 22 vanes and 28 blades and is modeled with a uniform flow upstream of the vane inlet, a pressure condition downstream of the blades, and three coolant flow conditions previously employed during experiments at Arizona State University. The simulations show the pressure fields downstream of the vanes and upstream of the blades interacting to form a complex pressure pattern above the rim seal. Circumferential distributions of 15 to 17 sets of ingress and egress velocities flow through the rim seal at the two modest coolant flow rate conditions. These flow distributions rotate at approximately wheel speed and are not equal to the numbers of blades or vanes. The seal velocity distribution for a high coolant flow rate with little or no ingestion into the stator wall boundary layer is associated with the blade pressure field. These pressure field characteristics and the rim seal ingress/egress pattern provide new insight to the physics of rim seal ingestion. Flow patterns within the rim cavity have large cells that rotate in the wheel direction at a slightly slower speed. These secondary flows are similar to structures noted in previous a 360 deg model and large sector models but not obtained in a single blade or vane sector model with periodic boundary condition at sector boundaries. The predictions of pressure profiles, sealing effectiveness, and cavity velocity components are compared with experimental data. © 2014 by ASME. Source

Jain A.,InfoTech Enterprises | Jain M.B.,Rungta Engineering College
Advances in Intelligent Systems and Computing | Year: 2013

There are a lot of uncertainties in planning and operation of electric power system, which is a complex, nonlinear, and non-stationary system. Advanced computational methods are required for planning and optimization, fast control, processing of field data, and coordination across the power system for it to achieve the goal to operate as an intelligent smart power grid and maintain its operation under steady state condition without significant deviations. State-of-the-art Smart Grid design needs innovation in a number of dimensions: distributed and dynamic network with two-way information and energy transmission, seamless integration of renewable energy sources, management of intermittent power supplies, real time demand response, and energy pricing strategy. One of the important aspects for the power system to operate in such a manner is accurate and consistent short term load forecasting (STLF). This paper presents a methodology for the STLF using the similar day concept combined with fuzzy logic approach and swarm intelligence technique. A Euclidean distance norm with weight factors considering the weather variables and day type is used for finding the similar days. Fuzzy logic is used to modify the load curves of the selected similar days of the forecast by generating the correction factors for them. The input parameters for the fuzzy system are the average load, average temperature and average humidity differences of the forecasted previous day and its similar days. These correction factors are applied to the similar days of the forecast day. The tuning of the fuzzy input parameters is done using the Particle Swarm Optimization (PSO) and Evolutionary Particle Swarm Optimization (EPSO) technique on the training data set of the considered data and tested. The results of load forecasting show that the application of swarm intelligence for load forecasting gives very good forecasting accuracy. Both the variants of Swarm Intelligence PSO and EPSO perform very well with EPSO an edge over the PSO with respect to forecast accuracies. © 2013 Springer. Source

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