Indian Institute of Technology Guwahati

About: Indian Institute of Technology Guwahati is a education organization based out in Guwahati, Assam, India. It is known for research contribution in the topics: Adsorption & Catalysis. The organization has 6933 authors who have published 17102 publications receiving 257351 citations.

Dynamic stability of a rotating sandwich beam with magnetorheological elastomer core

Abstract: In this work the dynamic stability of a rotating three layered symmetric sandwich beam with magnetorheological elastomer (MRE) core and conductive skins subjected to axial periodic loads has been investigated using finite element method (FEM). The derived governing equation of motion is in the form of a multi-degree of freedom Mathieu–Hill's equation with complex coefficients. The instability regions of the sandwich beam for the principal parametric resonance case have been determined by using the harmonic balance method. Effects of applied magnetic field, rotating speed, setting angle, hub radius, static load and dynamic load on the dynamic characteristics and instability regions of the sandwich beam are investigated. This work will find application in the passive and active vibration reduction of rotating sandwich structure using magnetorheological elastomer core, magnetic field and periodic axial load.

Fully compact higher-order computation of steady-state natural convection in a square cavity.

Abstract: The flow in a thermally driven square cavity with adiabatic top and bottom walls and differentially heated vertical walls for a wide range of Rayleigh numbers (10(3)< or =Ra< or =10(7)) has been computed with a fourth-order accurate higher-order compact scheme, which was used earlier only for the stream-function vorticity (psi-omega) form of the two-dimensional steady-state Navier-Stokes equations. The boundary conditions used are also compact and of identical accuracy. In particular, a compact fourth-order accurate Neumann boundary condition has been developed for temperature at the adiabatic walls. The treatment of the derivative source term is also compact and has been done in such a way as to give fourth-order accuracy and easy assimilation with the solution procedure. As the discretization for the psi-omega formulation, boundary conditions, and source term treatment are all fourth-order accurate, highly accurate solutions are obtained on relatively coarser grids. Unlike other compact solution procedure in literature for this physical configuration, the present method is fully compact and fully higher-order accurate. Also, use of conjugate gradient and hybrid biconjugate gradient stabilized algorithms to solve the symmetric and nonsymmetric algebraic systems at every outer iteration, ensures good convergence behavior of the method even at higher Rayleigh numbers.

Numerical Simulation of the Behavior of Geocell Reinforced Sand in Foundations

Abstract: This paper presents the finite-element simulations of the behavior of strip footings resting on sand beds, with different density of soil, reinforced with geocells of different dimensions. The strength and stiffness of sand confined with geocells is represented by an equivalent composite model developed from triaxial compression tests. The additional confining pressure due to geocells, calculated using hoop tension theory, is used to obtain the apparent cohesive strength imparted to sand due to geocells. The elastic modulus of the geocell encased sand is related to the elastic modulus of the unreinforced sand and the tensile modulus of the geocell material using an empirical equation. Load-settlement response of strip footings on geocell reinforced sand beds obtained from the numerical simulations are compared with the corresponding experimental results and the match is found to be good. In addition, numerical results showed that with the provision of a geocell layer, the mobilized shear stress contours b...