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Showing papers by "K. Murali published in 2008"


Journal ArticleDOI
TL;DR: In this article, a perforated circular cylinder (0.50 m diameter) encircling an impermeable cylinder ( 0.05m diameter) at a constant water depth of 0.7 m for both regular and random waves in the wave flume at the Department of Ocean Engineering, Indian Institute of Technology, Madras, India.
Abstract: An experimental investigations was carried out on a perforated circular cylinder ( 0.50 m diameter) encircling an impermeable cylinder ( 0.05 m diameter) at a constant water depth of 0.7 m for both regular and random waves in the wave flume at the Department of Ocean Engineering, Indian Institute of Technology, Madras, India. The porosity of the outer cylinder was varied from 4.54 to 19.15% to study the influence of porosity on wave forces on and water surface fluctuations in and around the twin cylinder system. A numerical method is developed based on the boundary integral equation method along with a porous body boundary condition, where the porosity is modeled using the resistance coefficient f and added mass coefficient Ca for regular waves. The resistance coefficient increases with the increase in porosity and wave heights except for a porosity of 4.54%, whereas the added mass coefficient is almost zero. Porosity in the range of 10–15% can be recommended for the perforated cylinder based on the exper...

31 citations


Journal Article
TL;DR: In this article, the propagation of the Indian Ocean Tsunami has been simulated using Shallow Water Equations using Unstructured Explicit Finite Element Model for solution of the governing equations The method of weighted residuals coupled with the finite element discretisation technique is then used to obtain a set of integral equations which can be assembled in a matrix form.
Abstract: Propagation of the Indian Ocean Tsunami has been simulated using Shallow Water Equations The three dimensional shallow water equations are reduced, by a process of vertical integration relating to the pertinent variables, to obtain equivalent equations in two dimensions An Unstructured Explicit Finite Element Model is adopted for solution of the governing equations The method of weighted residuals, in particular the Galerkin method, coupled with the finite element discretisation technique is then used to obtain a set of integral equations which can be assembled in a matrix form The domain is discretised with 9-noded lagrangian isoparametric elements Simpson’s 9-point integration rule, used to integrate over the 9-noded elements, leads to an explicit form of the assembled matrix (diagonal matrix) The above mentioned Unstructured Explicit Finite Element Method requires less computational resources and ensures higher order representation of the solution A computational domain (Bay of Bengal and northern part of the Indian Ocean) has been considered for simulation with an initial disturbance which resembles the type and location of the 2004 Indian Ocean Tsunami The wave elevations and deformations as well as time of travel of tsunami are reproduced The computed runup heights along Tamil Nadu coast of India were compared with the signature data and the agreement was found to be reasonable

4 citations