Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

The rotordynamic characteristics of gas turbine seals have been investigated in numerous previous studies. However, the effects of centrifugal growth were often ignored; and no extensive studies have been reported. To this end, the present work examines numerically the influence of centrifugal growth on the rotordynamic characteristics of a typical rotating labyrinth gas turbine seal. A computational framework developed based on combined 3D FE/CFD methodology along with an appropriate rotordynamic model has been employed. For a given seal clearance and eccentricity, various flow and operating conditions are investigated covering a range of pressure ratios and rotational speeds. A substantial variation in both the cross-coupled stiffness and direct damping is noticed and the influence increases with rotational speed. The stability characteristics reveal that centrifugal growth of the seal has a detrimental effect at relatively low pressure ratio and high rotational speed combinations. The computational approach is validated against a typical labyrinth seal results reported in the literature. © 2016 Elsevier Ltd. All rights reserved.

World University root node

Department of Mechanical Engineering

Tribology International

Rotordynamic characteristics of rotating labyrinth gas turbine seal with centrifugal growth

In the present work, parametric instability of asymmetric shaft mounted on bearings is studied. Towards this end, four different models of increasing complexity are studied. The equations corresponding to these models are formulated in the inertial reference frame. These equations involve a periodically varying coefficient. This is similar to classical Mathieu equation but in a multi-degree of freedom context. As such, under suitable parameter combination these systems result in growing oscillation amplitudes or instability. For wider generalization, the equations and results are presented in a non-dimensional form. The unstable parameter regimes are found using the Floquet theory and perturbation methods. These results are also corroborated with existing results in the literature. The nature of the stability boundary and its dependence on various system parameters is discussed in elaborate detail. The stability boundary can be used to determine unstable operating speed ranges for different asymmetric shaft cross-sections. Further, material, geometry and bearing selection guidelines for ensuring stable operations can be inferred from these results. © 2015 Elsevier Ltd. All rights reserved.

Journal of Sound and Vibration

Instability of asymmetric shaft system

The study area is the Lower Flint River Basin which is at the center of water conflicts in the southeastern USA. This study focuses on a systematic evaluation and separation of El Niño Southern Oscillation (ENSO) induced droughts and irrigation water withdrawal impacts on flow levels using a novel and powerful statistical technique, called JRFit. JRFit procedure was applied to quantify significant differences in streamflows, baseflows, and low flow statistics during non-irrigation (NI) and irrigation (IR) periods associated with ENSO phases. The results indicate that overall streamflow levels have decreased by approximately 20% after the introduction of irrigation in the study area. Lowering of flow levels mainly occur during La Niña phases which gets exacerbated (decreased by 50%) during growing season of IR compared to NI periods. Flow duration curve analysis showed that the frequency of low flows has increased during IR period impairing aquatic ecosystem. This is the first time an elimination approach is used to separate and quantify the impacts of anthropogenic and climate signals on water resources. This approach avoids the need of using complex and data intensive groundwater/surface water models in studying climate-stream-aquifer interactions which can be replicated easily in other data scarce watersheds. This study provides useful information to policymakers to devise irrigation water withdrawal policies during La Niña growing seasons for maintaining flow levels in the study area. © 2016 The Authors

Department of Civil Engineering

Fulltext

Journal of Hydrology: Regional Studies

Climate variability and irrigation impacts on streamflows in a Karst watershed—A systematic evaluation

We investigate the action of global noise and local channels, namely, amplitude-damping, phase-damping, and depolarizing channels, on monogamy of quantum correlations, such as negativity and quantum discord, in three-qubit systems. We discuss the monotonic and non-monotonic variation, and robustness of the monogamy scores. By using monogamy scores, we propose a two-step protocol to conclusively identify the noise applied to the quantum system, by using generalized Greenberger–Horne–Zeilinger and generalized W states as resource states. We discuss a possible generalization of the results to higher number of parties. © 2016 Elsevier B.V.

Department of Physics

Physics Letters, Section A: General, Atomic and Solid State Physics

Conclusive identification of quantum channels via monogamy of quantum correlations

We investigate the static and dynamical patterns of entanglement in an anisotropic XY model with an alternating transverse magnetic field, which is equivalent to a two-component one-dimensional Fermi gas on a lattice, a system realizable with current technology. Apart from the antiferromagnetic and paramagnetic phases, the model possesses a dimer phase which is not present in the transverse XY model. At zero temperature, we find that the first derivative of bipartite entanglement can detect all the three phases. We analytically show that the model has a "factorization line" on the plane of system parameters, in which the zero-temperature state is separable. Along with investigating the effect of temperature on entanglement in a phase plane, we also report a nonmonotonic behavior of entanglement with respect to temperature in the antiferromagnetic and paramagnetic phases, which is surprisingly absent in the dimer phase. Since the time dynamics of entanglement in a realizable physical system plays an important role in quantum information processing tasks, the evolutions of entanglement at small as well as large time are examined. Consideration of large-time behavior of entanglement helps us to prove that in this model, entanglement is always ergodic. We observe that other quantum correlation measures can qualitatively show similar features in zero and finite temperatures. However, unlike nearest-neighbor entanglement, the nearest-neighbor information-theoretic measures can be both ergodic as well as nonergodic, depending on the system parameters. © 2016 American Physical Society.

Physical Review A

Static and dynamical quantum correlations in phases of an alternating-field XY model

6 th International and 43 rd National Conference on Fluid Mechanics and {\ldots}

Impinging Flame Jets of Perforated Plate Burner: Heat Transfer Aspects

Oblique flame jet impingement finds a wide range of domestic and industrial applications. An experimental investigation is carried out to study the effect of oblique flame jet impingement on the heat transfer characteristics. An asymmetric boundary layer is formed on the impingement surface due to oblique impingement. Steady state technique using one dimensional energy balance across the target plate is employed to determine the local heat transfer coefficient and the reference temperature of the impinging flame jet. The effect of the mixture Reynolds number (400-1200), mixture equivalence ratio (0.8-1.5), burner or plate inclination (0-45°) and burner to plate distance (2-6 times the burner diameter) on the heat transfer characteristics are investigated. It is found that stoichiometric mixture provides optimum Nusselt number distribution and lower burner to plate spacing provides maximum effectiveness for impinging premixed cone flames. Normal impingement resulted smooth heat flux distribution and better thermal performance. Correlations are developed for stagnation point Nusselt number and effectiveness. © 2016 Elsevier Ltd. All rights reserved.

International Journal of Heat and Mass Transfer

Heat transfer characteristics of premixed methane-air flame jet impinging obliquely onto a flat surface

Transportation Research Board 95th Annual Meeting 1

A Game-Theoretic Model to Identify Critical Links on Urban Road Networks

Significant progress has been observed in recent years in the synthesis of allylic amines, which are important building blocks in synthetic chemistry. Most of these processes are effective toward the preparation of allylic amines, with limited potential to introduce three or four different substituents on the olefinic unit in a stereocontrolled fashion. Therefore, the discovery of a mild and operationally simple protocol allowing such challenging stereoselective synthesis of multisubstituted allylic amines remains an inspiring target. Herein, we report the first general and practical methodology for the stereoselective synthesis of tri- and tetrasubstituted allylic amines based on Pd-catalyzed conversion of allyl surrogates readily obtained from cyclic vinyl carbonates. These rare conversions are characterized by excellent stereoselectivity, operational simplicity, mild reaction conditions, and wide scope in reaction partners. DFT studies were performed to rationalize the stereocontrol in these allylic amine formation reactions, and evidence is provided that the formation of a six-membered palladacyclic intermediate leads toward the formation of (Z)-configured allylic amine products. © 2016 American Chemical Society.

Department of Chemistry

Journal of the American Chemical Society

Stereoselective and Versatile Preparation of Tri- and Tetrasubstituted Allylic Amine Scaffolds under Mild Conditions

We show that the center of the Goldman Lie algebra associated to a closed orientable surface is generated by the class of the trivial loop. For an orientable nonclosed surface of finite type, the center is generated by closed curves which are either homotopically trivial or homotopic to boundary components or punctures. © 2016, Mathematical Sciences Publishers. All rights reserved.