Browsing by Author "Rajan, I."

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    Flow Dynamics Of Lid-Driven Cavities With Obstacles Of Various Shapes And Configurations Using The Lattice Boltzmann Method
    (Yildiz Technical University, 2021) Rajan, I.; Arumuga Perumal, D.
    This work implements the emerging computational technique namely the Lattice Boltzmann Method (LBM) to a fluid flow problem of single sided lid-driven cavities with various shapes of obstacles placed in it. The numerical methodology employs the Single-Relaxation-Time (SRT) model applicable to low Mach number hydrodynamic problem for incompressible flow regime. Three geometrical shapes of the obstacles considered are circular, square, and elliptic. Cavity with obstacles exhibited remarkable circulation zones and structures in contrast to the classical lid driven cavity. The flow mechanics and the vortex dynamics are studied for various values of Reynolds Number (Re = 100, 400, and 1000). Due to the introduction of the obstacles, a strong induced vortex forms close to the obstacles and its size changes interestingly with the variation of Reynolds number, which is captured by LBM. Further the study is extended to examine the vortex phenomena induced by changing the position of the obstacles within the cavity. It is observed that the flow structures change dramatically with little change in the position of obstacle inside the cavity which helps to identify position with enhanced mixing characteristics. © 2021. Journal of Thermal Engineering. All rights reserved.
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    Fluid flow characteristics in double-sided lid-driven microcavity using lattice boltzmann method
    (Begell House Inc. orders@begellhouse.com, 2019) Rajan, I.; Arumuga Perumal, D.A.; Yadav, A.K.
    In this study, we analyze the fluid flow characteristic of rarefied gas flows in double-sided lid-driven microcavity subjected to various combinations of boundary conditions that simulate the slip at the walls using lattice Boltzmann method (LBM) constituting a single relaxation time (SRT) model. The fluid motion inside a closed square container with two rigid walls and two moving walls constitutes an exemplar for internal vortex flows. First, a complicated geometry, namely, the single-sided lid-driven microcavity is studied using the LBM-SRT model. Next, this code is extended to simulate flows in a double-sided microcavity flow. Numerical computation of fluid flow incorporating various slip boundary conditions as bounce-back and specular boundary condition (BSBC) for different values of tangential accommodation momentum coefficient (TMAC) has been investigated. Various values of Knudsen number in the slip and transition regime (Kn = 0.01, 0.05, 0.10, 0.135, and 0.15) along with different aspect ratios of 0.33, 0.50, 1.0, 2.0, and 3.0 have been considered in this study. The streamline patterns and velocity profiles were obtained for different Knudsen numbers. The formation and movement of primary vortices have been well captured with the variation of Knudsen numbers for different aspect ratios of microcavity. © 2019 by Begell House, Inc.
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    Lattice Boltzmann computation of creeping fluid flow in roll-coating applications
    (2018) Rajan, I.; Kesana, B.; Perumal, D.A.
    Lattice Boltzmann Method (LBM) has advanced as a class of Computational Fluid Dynamics (CFD) methods used to solve complex fluid systems and heat transfer problems. It has ever-increasingly attracted the interest of researchers in computational physics to solve challenging problems of industrial and academic importance. In this current study, LBM is applied to simulate the creeping fluid flow phenomena commonly encountered in manufacturing technologies. In particular, we apply this novel method to simulate the fluid flow phenomena associated with the "meniscus roll coating" application. This prevalent industrial problem encountered in polymer processing and thin film coating applications is modelled as standard lid-driven cavity problem to which creeping flow analysis is applied. This incompressible viscous flow problem is studied in various speed ratios, the ratio of upper to lower lid speed in two different configurations of lid movement - parallel and anti-parallel wall motion. The flow exhibits interesting patterns which will help in design of roll coaters. � 2018 Author(s).
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    Lattice Boltzmann computation of creeping fluid flow in roll-coating applications
    (American Institute of Physics Inc. subs@aip.org, 2018) Rajan, I.; Kesana, B.; Arumuga Perumal, D.A.
    Lattice Boltzmann Method (LBM) has advanced as a class of Computational Fluid Dynamics (CFD) methods used to solve complex fluid systems and heat transfer problems. It has ever-increasingly attracted the interest of researchers in computational physics to solve challenging problems of industrial and academic importance. In this current study, LBM is applied to simulate the creeping fluid flow phenomena commonly encountered in manufacturing technologies. In particular, we apply this novel method to simulate the fluid flow phenomena associated with the "meniscus roll coating" application. This prevalent industrial problem encountered in polymer processing and thin film coating applications is modelled as standard lid-driven cavity problem to which creeping flow analysis is applied. This incompressible viscous flow problem is studied in various speed ratios, the ratio of upper to lower lid speed in two different configurations of lid movement - parallel and anti-parallel wall motion. The flow exhibits interesting patterns which will help in design of roll coaters. © 2018 Author(s).
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    Simulation of fluid flow in a lid-driven cavity with different wave lengths corrugated walls using Lattice Boltzmann method
    (Taiwan Institute of Chemical Engineers, 2023) Fatima, N.; Rajan, I.; Arumuga Perumal, D.A.; Anbalagan, A.; Ahmed, S.A.A.; Gorji, M.R.; Ahmad, Z.
    Background: The Lid-driven cavity (LDC) flow is an interesting problem in fluid mechanics. The lattice Boltzmann Method (LBM) is used to simulate fluid flow in a LDC with different wave lengths corrugated walls. Methods: The D2Q9 model is used for the 2D bounded domain where the analysis of bottom-bounded wall corrugations on the flow features is analyzed. For validation, a square corrugation along the bottom wall with a driven top wall is considered. A lattice size independence study is performed and the LBM code is substantiated with published results for different values of Reynolds number. The code is then modified by using sinusoidal corrugated walls with different wavelengths along the bottom surface. Significant finding: The streamline patterns, vorticity contours and kinetic energy contours are studied for different Reynolds number. Results shown that the position, number and size of vortices depend on the number of corrugations and value of Reynolds number used. The secondary vortices tend to increase in size as the Reynolds number increase. The kinetic energy contours show maximum energy near the top wall which reduces inside the cavity. © 2023