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Hyderabad, India

Satyanarayana B.,VNR Vignana Jyothi Institute of Engineering and Technology | Ranga Janardhana G.,Jawaharlal Nehru Technological University Anantapur | Hanumantha Rao D.,MVSR Engineering College
Indian Journal of Engineering and Materials Sciences

Inconel 718, a Nickel based super alloy which has wide applications in aerospace industry particularly in the hot sections of gas turbine engines due to their high temperature strength and corrosion resistance. It is known as being among the most difficult-to-cut materials. This paper presents an optimum process parameters (speed, feed and depth of cut) to minimize the cutting force, surface roughness and tool flank wear together in CNC high speed dry turning of Inconel 718 using Taguchi method based Grey relational analysis. The study involved nine experiments based on Taguchi orthogonal array and the result indicates that the optimal process parameters are 60 m/min for speed, 0.05 mm/rev for feed and 0.2 mm for depth of cut from the selected range. Also the significant process parameters have been found out for the above process optimization by performing ANOVA. Confirmation tests with the optimal levels of cutting parameters are carried out in order to illustrate the effectiveness of the method. Source

This paper attempts to apply Big-Bang and Big-crunch (BB-BC) based evolutionary algorithm to solve Multi-objective (M0) Optimization problem by vector optimization approach. A reformulated version referred to as modified BB-BC (MBB-BC) is used to overcome the deficiency of BB-BC. The crowding distance measure is included in the proposed M0 algorithm to achieve the spread among obtained non-dominated solutions. The Economic Environmental Dispatch (EED) objectives are minimized by vector approach while maintaining equality and inequality constraints. The proposed algorithm is tested for bench mark MO test functions of varying difficulty in converging to a true Pareto front. As an application to optimal EED, an eleven buses and IEEE-30 bus transmission utilities are considered. The convergence and spread metrics are used to assess the extent of success. The best compromise solutions are reported using Fuzzy decision making approach. © JES 2015. Source

Durga Prasad P.V.,MVSR Engineering College | Gupta A.V.S.S.K.S.,JNTUH College of Engineering
International Communications in Heat and Mass Transfer

An investigation is made experimentally with an attempt to enhance the rate of heat transfer of Al2O3 nanofluid in a U-tube heat exchanger with twisted tape insert. The heat transfer coefficients and the corresponding friction factors needed for performance analysis are determined at variable operating conditions of the heat exchangers with particle volume concentration of 0.01% and 0.03% and twist ratios ranging between 5 and 20. Experimental data are obtained at flow rates ranging from 0.0333 to 0.2667 kg/s and Reynolds number ranging from 3000 to 30,000. The Nusselt number of entire pipes for 0.03% concentrations of nanofluid with twisted tape inserts is enhanced by 31.28% compared to water while the friction factor is increased by 1.23 times compared to water with twisted tape insert of H/D = 5. Correlations are developed to estimate the Nusselt number and friction factor. The results of the investigation indicated significant improvement in the performance parameters of the heat exchanger with a rise in volume concentration of the nanoparticle. © 2016 Elsevier Ltd. Source

Kandasamy J.,MVSR Engineering College | Hussain M.M.,JNTUH College of Engineering | Rajesham S.,Pulla Reddy Institute of Technology
Materials and Manufacturing Processes

Friction stir welding (FSW) experiments are conducted on AA7075 and AA6061 alloys under optimized conditions with copper as intermediate inclusion on the faying sides of the base material assisted by external heating from the root side during the process. The concept behind the experimentation is to minimize the temperature gradient that exists between the top and bottom sides of the plates. The work attempts to relocate the crack initiation point from the root of the retreating side, as in conventional friction stir weldments due to the variation in material flow along the weld cross-section. Analysis of the formed intermetallic compound (IMC) indicates that the interaction of AA7075, AA6061 alloys with copper, in coating form, enhances the bond strength by formation of Al2Cu and Al4Cu9 IMCs. High thermal conductivity of the copper in coating form along with external heating from the root side has minimized the temperature gradient and maintains homogenous material flow in the weld zone and increased bond strength. © 2012 Copyright Taylor and Francis Group, LLC. Source

Narang N.,Thapar University | Dhillon J.S.,Sant Longowal Institute of Engineering And Technology | Kothari D.P.,MVSR Engineering College
International Journal of Electrical Power and Energy Systems

This paper presents best weight pattern evaluation approach to solve short-term multi-objective hydrothermal generation scheduling (HTGS) which determines the allocation of power demand among the committed generating units, to minimize operating cost and minimal impacts on environment subjected to physical and technological constraints. A multi-chain interconnected hydro system having non-linear relationship between water discharge rate and power generation is undertaken with due consideration of water transport delay between connected reservoirs. The best weights are computed by conventional statistical measures, which characterize the correlation coefficients matrix evolution. The solution methodology hybridizes global and local search techniques. Predator-prey optimization (PPO) is undertaken as a global search technique and Powell's pattern search (PPS) is exploited as a local search technique. The results among the competing objectives obtained by the proposed method are compared with various results reported in the literature. The sensitivity and robustness of the proposed technique are evaluated by performing statistical analysis of results obtained based on independent runs. The integration of PPO and PPS improves the quality of solution and convergence characteristics. © 2014 Elsevier Ltd. All rights reserved. Source

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