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Ramesh Bapu B.R.,Chennai Institute of Technology | Saravanakumar L.,Jawaharlal Nehru Technological University Anantapur | Durga Prasad B.,Jawaharlal Nehru Technological University Anantapur
Journal of the Energy Institute | Year: 2017

This paper describes the results of an experimental investigation carried out in a single cylinder, variable compression ratio, CI engine fueled with Calophyllum Inophyllum Methyl Ester (CIME) blended with diesel. An earlier investigation made by the investigators using CIME blends in conventional Hemispherical Combustion Chamber (HCC), showed that the blend B20 provides the optimum results and hence B20 blend was used as a test fuel for further investigations. Further, the emissions like unburned hydrocarbon (UBHC), carbon monoxide (CO) and smoke have been noticed higher with diesel. In this investigation, attempts have been made to reduce the emissions and improve the combustion characteristics by enhancing the fuel–air mixture preparation and its turbulence by changing the design of piston bowl geometry. For this, a Modified Hemispherical Combustion Chamber (MHCC) has employed and the results were compared with conventional Hemispherical Combustion Chamber (HCC). The fuel–air mixture formation in the cylinder was simulated at different positions of the piston (at TDC, mid of stroke and at BDC) using Ansys Fluent software. Conclusively, from the investigations, MHCC was recognized as an ideal choice of combustion chamber design for the entire range of operations of the engine using the blend (B20) than that of HCC. © 2015 Energy Institute

Nithyanandan K.,Pondicherry University | Raja R.V.J.,Central University of Tamil Nadu | Porsezian K.,Pondicherry University | Kalithasan B.,Chennai Institute of Technology
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

We investigate the cross-phase-modulation-induced modulational instability (MI) of two co-propagating optical beams in the system of relaxing Kerr nonlinearity with the effect of higher-order dispersion (HOD) and walk-off effect. We identify and discuss the salient features of relaxation of nonlinear responses and HOD using suitable theoretical model. First, we analyzed the impact of HOD and walk-off on the MI spectrum and found both analytically and numerically that the MI exhibits alternate characteristics like the evolution of different spectral bands in addition to the conventional MI bands. The walk-off effects in the virtue of HOD not only consist of the conventional group velocity mismatch (GVM) but also the difference in third-order dispersion (TOD) of the two beams, and thereby significantly modify the dynamical behavior of the MI. We also consider the combined effect of relaxation of nonlinear response and the HOD effects, and we observe that any finite value of delay leads to the evolution of two unstable modes and thereby extends the range of unstable frequency; HOD on the other hand along with the walk-off effect brings other characteristic spectral bands. A detailed discussion about the various combinations of parameters and the relative competence of one over the other on the MI spectrum is presented. Thus the evolution of MI from cross-phase modulation in the system of relaxing Kerr nonlinearity is emphasized in detail and the influence of HOD and the walk-off effect are highlighted. © 2012 American Physical Society.

Rajagopal K.,Defence University | Vaidhyanathan S.,Vel Technology University | Karthikeyan A.,Chennai Institute of Technology | Duraisamy P.,Defence University
Electrical Engineering | Year: 2016

This paper investigates the dynamic properties and chaos control in a fractional order brushless DC (BLDC) motor. The fractional order model of the brushless DC motor has been derived from its integer order model. Then the qualitative properties of the fractional order BLDC motor are derived. Bifurcation analysis of the BLDC motor with the fractional order has been also discussed. Fractional order chaos control in the BLDC motor is achieved using sliding mode control, robust control and extended back-stepping control. © 2016 Springer-Verlag Berlin Heidelberg

Mahalingam S.,Sathyabama University | Ramesh Bapu B.R.,Chennai Institute of Technology
International Review of Mechanical Engineering | Year: 2013

In the fast growing world of automobiles, the demand for petroleum products is increasing day by day. Many of renewable energies are used to full fill that demand. One of the best alternatives is the use of biodiesel. In this study a dual fuel blend with pure diesel in a single cylinder direct injection constant speed diesel engine was analyzed by varying the power outputs with different proportions of the fuel blends. In the dual fuel operation, the rubber seed oil and jatropha oil blends with diesel. The proportions of 20% and 40% blend have been investigated on volume basis. In this dual fuel operation is observed that they have higher emission of hydrocarbon (HC) and carbon monoxide (CO) emissions than the ester, diesel blend. The ignition delay was reduced using dual fuel blend with diesel and efficiencies were improved. The proportion, B20 (20% of biodiesel) is gives the optimum efficiency with low emission. © 2013 Praise Worthy Prize S.r.l. - All rights reserved.

Anand K.T.,Sathyabama University | John Rajan A.,Sathyabama University | Narayanan K.V.,Sathyabama University | Ramesh Bapu B.R.,Chennai Institute of Technology
Fibres and Textiles in Eastern Europe | Year: 2016

An investigation of various factors which affect the lead time in spinning mills which produce 14.76 tex (40 Ne) carded yarns linear density is reported. For this study, data were collected from 27 mills producing 14.76 tex carded yarns of linear density. The important parameters which affect the lead time were obtained by principal component analysis of the data. Correlation matrix and multiple regression analysis were carried out taking into account the lead time as the dependent variable and HOK (the number of Operative Hours required to produce 100 kg of yarn), FQI (Fibre Quality Index), YQI (Yarn Quality Index) and spindle production as independent variables. The reliability of the data was checked by Cronbach’s alpha, which indicated 0.839. Other tests such as the Kruskal-Wallis test, Durbin Watson test, KMO (Kaiser – Meyer Olkin) and Bartlett’s test were also done to find out their association. The results show that of all the parameters considered the, lead time exerts maximum influence on spindle production, HOK and the yarn quality index in carded counts. © 2016, Institute of Biopolymers and Chemical Fibres. All rights reserved.

Nachiappan N.,Sri Venkateswara College of Engineering | Nachiappan N.,Alagappa University | Kalaignan G.P.,Alagappa University | Sasikumar G.,Chennai Institute of Technology
Ionics | Year: 2013

Proton exchange membrane fuel cells [PEMFC] have become highly attractive for stationary as well as mobile energy applications due to their good efficiency compact cell design and zero emissions. PEM fuel cells mainly consist of anode and cathode containing platinum/platinum alloy electrocatalysts and Nafion membrane as the electrolyte. They operate on hydrogen fuel, which is generally produced by reforming of hydrocarbons, alcohols such as methanol and may contain large amounts of impurities such as methanol, carbon dioxide, trace amounts of carbon monoxide, etc. The studies on the effect of methanol impurity in hydrogen on fuel cell performance and methods of mitigation of poisoning are very important for the commercialization of fuel cells and are described in a limited number of papers only. In this paper, we present the studies on the influence of methanol impurity in hydrogen for the PEM fuel cells. The effect of various parameters such as methanol concentration, cell voltage, current density, exposure time, reversibility, operating temperature, etc. on the cell performances was investigated using pure hydrogen. Various methods of methanol poisoning mitigation were also investigated. © 2012 Springer-Verlag.

Vaidyanathan S.,Tamil University | Azar A.T.,Benha University | Rajagopal K.,Chennai Institute of Technology | Alexander P.,Chennai Institute of Technology
International Journal of Modelling, Identification and Control | Year: 2015

This research work describes the design and SPICE implementation of a 12-term novel hyperchaotic system with four quadratic nonlinearities. The Lyapunov exponents of the dissipative novel hyperchaotic system are obtained as L1 = 4.1043, L2 = 0.1571, L3 = 0 and L4 = -34.2529. The maximal Lyapunov exponent (MLE) of the novel hyperchaotic system is L1 = 4.1043. The Lyapunov dimension of the hyperchaotic system has been obtained as DL = 3.1244. The qualitative properties of the novel hyperchaotic system are described in detail. Moreover, the hyperchaotic system has been implemented in LTspice IV (SPICE simulator) and the outputs are obtained in SPICE showing hyperchaos of the novel system. Next, active control method has been applied for the global synchronisation of the novel hyperchaotic systems and the synchronisation result has been proved using Lyapunov stability theory. The active controller for the global synchronisation of the identical novel hyperchaotic systems has been implemented in LTspice IV and the SPICE simulation results have been detailed. Copyright © 2015 Inderscience Enterprises Ltd.

Balan K.N.,Rajiv Gandhi University | Ramesh Bapu B.R.,Chennai Institute of Technology | Roy R.,Rajiv Gandhi University
Advanced Materials Research | Year: 2013

Various researches are being conducted in many parts of the world, to improve the surface characteristics of the materials. Thermal spray coating is one of the methods used for enhancing the surface property of the material. Our experiment deals with the study of detonation gun spray coating of WC-12Co, WC-10Co-4Cr and Cr2C3-25NiCr powders. The coating was done on SS316 substrate by varying the process parameters. The process parameters were optimized using Taguchi method to obtain greater hardness. © (2013) Trans Tech Publications, Switzerland.

Elangovan P.,Chennai Institute of Technology | Yoo C.K.,Kyung Hee University
Journal of Computational and Theoretical Nanoscience | Year: 2013

Numerical calculations of the excitonic absorption spectra in a strained ZnxCd1-xO/Mg0.1Zn0.9O quantum dot are investigated for various Cd content taking into account the geometrical confinement. The quantized energies of the exciton as a function of dot radius for various Cd alloy content are computed in a strained ZnxCd 1-xO/Mg0.1Zn0.9O quantum dot and thereby the interband emission energy is calculated considering the internal electric field induced by the spontaneous and piezoelectric polarizations. The nonlinear optical properties such as optical absorption and the changes of refractive index as a function of photon energy for various values of Cd alloy content and the optical intensities are discussed. Increase of exciton binding energy and the corresponding optical band gap with the Zn content imply that the confinement of carriers increases with composition x. The main results show that the confined energies and the transition energies between the excited levels are significant for smaller dots. Non-linearity band gap with the increase in Zn content is observed for smaller dots in the strong confinement region and the magnitude of the absorption spectra increases for the transitions between the higher excited levels. Copyright © 2013 American Scientific Publishers All rights reserved.

On the basis of model solid theory, the band offsets for a Zn1-xinMgxinSe/Zn1-xoutMgxoutSe quantum dot structure are determined. The exciton binding energies due to heavy and light holes with the variation of Mg alloy are reported. The effect of mismatch between the dielectric constants between the dot and the barrier is taken into account. The exciton transition energy as functions of dot radius and Mg content is computed. The dependence of the excitonic transition energies on the geometrical confinement and the Mg alloy is brought out. © 2012 Elsevier B.V.

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