IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

We develop both stable and stabilized methods for imposing Dirichlet constraints on embedded, three-dimensional surfaces in finite elements. The stable method makes use of the vital vertex algorithm to develop a stable space for the Lagrange multipliers together with a novel discontinuous set of basis functions for the multiplier field. The stabilized method, on the other hand, follows a Nitsche type variational approach for three-dimensional surfaces. Algorithmic and implementational details of both methods are provided. Several three-dimensional benchmark problems are studied to compare and contrast the accuracy of the two approaches. The results indicate that both methods yield optimal rates of convergence in various quantities of interest, with the primary differences being in the surface flux. The utility of the domain integral for extracting accurate surface fluxes is demonstrated for both techniques. Copyright © 2011 John Wiley &amp; Sons, Ltd.<h2>&nbsp;</h2>&nbsp;

Department Of Civil Engineering

World University root node

International Journal for Methods in Engineering

Robust imposition of Dirichlet boundary conditions on embedded surfaces

Department of Humanities and Social Sciences

Department Of Physics

Department of Applied Mechanics

Department of Aerospace Engineering

Department of Ocean Engineering

Department of Metallurgical and Materials Engineering

Department of Mechanical Engineering

Department of Mathematics

Economic and Political Weekly

Erratum: Sheer insensitivity (Economic and Political Weekly (2011))

In this work, an application of damping using shape memory alloy bracings on a simple frame is analyzed using a modified form of a popular shape memory alloy constitutive model. The popular model is first modified to remove inherent inconsistencies and is then further improved to also simulate hysteresis / subloop response that are essential for damping applications. Simple static and dynamic cases of loading are simulated to demonstrate its effectiveness. The results are discussed in the light of suitability to damping under earthquake excitations.

GENERAL

Journal of Structural Engineering (Madras)

Analysis for damping in structures braced with superelastic SMA wires

A non-premixed diffusion flame formed by co-flowing streams of air and fuel downstream of the burner is subjected to externally imposed oscillations in pressure, velocity, and density, in the transverse direction to the mean flow. The problem is investigated by means of numerical simulation. The flame is treated in a two-dimensional domain, and the response of its heat release rate fluctuations to the external excitation is examined. A relationship between a threshold amplitude and the frequency of the external excitation exists for which the flame blows off (at low frequency) or blows out (at high frequency). The classical response function curve dropping with frequency is captured when stable oscillations are observed. The response is linear with the imposed amplitude. The oscillatory combustion in the presence of the prevalent/imposed transverse velocity oscillations is coupled to the linear longitudinal acoustic modes of the duct by placing the burner somewhere along the length. Multiple longitudinal modes are simultaneously and spontaneously excited; the mode that grows predominantly depends upon the burner location in the duct. This shows that the combustion zone acts as a local nonlinearity in transferring energy between transverse modes and longitudinal modes, even when the acoustic oscillations are in the linear regime.

Collection of Technical Papers - 43rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference

Response of Non-Premixed Ducted Flame to Transverse Oscillations and Longitudinal Acoustic Coupling

In today's competitive business climate characterized by uncertain oil markets, responding effectively and speedily to market forces, while maintaining reliable operations, is crucial to a refinery's bottom line. Optimal crude oil scheduling enables cost reduction by using cheaper crudes intelligently, minimizing crude changeovers, and avoiding ship demurrage. So far, only discrete-time formulations have stood up to the challenge of this important, nonlinear problem. A continuous-time formulation would portend numerous advantages, however, existing work in this area has just begun to scratch the surface. In this paper, we present the first complete continuous-time mixed integer linear programming (MILP) formulation for the short-term scheduling of operations in a refinery that receives crude from very large crude carriers via a high-volume single buoy mooring pipeline. This novel formulation accounts for real-world operational practices. We use an iterative algorithm to eliminate the crude composition discrepancy that has proven to be the Achilles heel for existing formulations. While it does not guarantee global optimality, the algorithm needs only MILP solutions and obtains excellent maximum-profit schedules for industrial problems with up to 7 days of scheduling horizon. We also report the first comparison of discrete- vs. continuous-time formulations for this complex problem.

Department Of Chemical Engineering

Chemical Engineering Science

A new continuous-time formulation for scheduling crude oil operations

The discovery of periodic mesoporous MCM-41 and related molecular sieves has attracted significant attention from a fundamental as well as applied perspective. They possess well-defined cylindrical/hexagonal mesopores with a simple geometry, tailored pore size, and reproducible surface properties. Hence, there is an ever-growing scientific interest in the challenges posed by their processing and characterization and by the refinement of various sorption models. Further, MCM-41-based materials are currently under intense investigation with respect to their utility as adsorbents, catalysts, supports, ion-exchangers, and molecular hosts. In this article, we provide a critical review of the developments in these areas with particular emphasis on adsorption characteristics, progress in controlling the pore sizes, and a comparison of pore size distributions using traditional and newer models. The model proposed by the authors for adsorption isotherms and criticalities in capillary condensation and hysteresis is found to explain unusual adsorption behavior in these materials while providing a convenient characterization tool.

Department Of Chemistry

Recent Advances in Processing and Characterization of Periodic Mesoporous MCM-41 Silicate Molecular Sieves