Faculty Publications
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Item Inertial Migration of Cylindrical Particle in Stepped Channel—A Numerical Study(Springer Science and Business Media Deutschland GmbH, 2022) Neeraj, M.P.; Maniyeri, R.; Kang, S.Inertial migration of solid rigid particle in fluid flow occurs by the virtue of pure mechanical forces and it can play a pivotal role in separation techniques. The present computational study tries to capture the inertial migration dynamics of single rigid neutrally buoyant cylindrical particle in fluid flow which is residing in a stepped (sudden contraction) channel by determining the equilibrium position and migration time. The immersed boundary method based on feedback forcing scheme is used to develop the numerical model. The particle performs both translation and rotation motion according to the fluid flow condition and is modelled as rigid immersed boundary and the governing fluid momentum, and continuity equations are discretized using finite volume method in a staggered grid system and solved using semi-implicit fractional step algorithm. The study is mainly performed for centre and off-centre initial positions and its influence on the equilibrium position and migration time. It is observed that the equilibrium position is dependent on the initial position of release of particle. As initial position shifts from centre of channel, the particle equilibrium position also shifts accordingly. Further, the effect of height and length of step (contraction portion) on lateral migration is explored. The equilibrium position is found to be shifting towards the upper wall with decrease in height of step. However, the change in height of step does not have any significant effect on migration time of particle. It is identified that the increase in length of step reduces the migration time of particle although the equilibrium position remains same. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Numerical Simulation of Inertial Migration of Elliptical Particle Using Immersed Boundary Method(Springer Science and Business Media Deutschland GmbH, 2023) Neeraj, M.P.; Maniyeri, R.The particles suspended in a flowing fluid migrates with respect to the lift forces experienced which is generated by the virtue of the fluid. This type of movement which occurs without the aid of any external forces is known as inertial migration. The present work tries to construct a two-dimensional computational model to analyse the lateral migration of a neutrally buoyant rigid elliptical particle in Poiseuille flow which takes place in straight channel. The feedback forcing based immersed boundary methodology is adopted to build the numerical model. The inertial migration is addressed by studying the characteristics of equilibrium position and migration time. The effect of aspect ratio and initial release configuration of elliptical particle on the equilibrium position and migration time is observed with the use of the simulation results. The equilibrium is observed to be close to 0.6 times half the half of height of channel or more specifically at 0.27 for an aspect ratio of 3.333. However, with reduction in aspect ratio to 1.5 the equilibrium position shifts closer to 0.26. The decrease in aspect ratio from 3.333 to 1.5 also produces reduction in migration time from 5.906 to 4.074. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Lateral migration of cylindrical particle in a constricted microchannel—A numerical study(John Wiley and Sons Inc, 2023) Neeraj, M.P.; Maniyeri, R.Inertial migration of a single cylindrical particle in a constricted microchannel is addressed in this work. A computational model (two-dimensional) has been constructed with the assistance of the immersed boundary finite volume method. The feedback forcing strategy is utilized for the simulation of lateral migration. The parameters like equilibrium position, migration time, and shortest equilibrium distance are computed to analyze the inertial migration characteristics of the particle. Also, a comprehensive parametric study has been performed on the migration behaviour of particles inside the constricted channel by addressing the effects of Reynolds number, diameter, initial release position, and constriction clearance. The parametric study shows that the equilibrium position changes with variations in the initial release position and particle diameter. On the other hand, it stays unaffected by changes in Reynolds number and constriction clearance. The parameters like the shortest equilibrium distance and migration time increase with a rise in Reynolds number and particle diameter. On the other hand, it reduces with the reduction in constriction clearance. Inspired by the parametric study results, in the following stage, a prediction model is created with an artificial neural network algorithm. This is used for an effective forecast of equilibrium position, migration time, and shortest equilibrium distance. Further, the computational model is utilized to check for the existence of a critical Reynolds number for the particle movement in a constricted microchannel. It is observed that the critical Reynolds number remains unchanged with a change in particle diameter. However, it increases linearly with an increase in constriction clearance. © 2022 Canadian Society for Chemical Engineering.Item Lateral Migration of Variously Shaped Particles: A Computational Study(John Wiley and Sons Inc, 2023) Neeraj, M.P.; Maniyeri, R.The current work deals with the simulation of lateral migration of differently shaped particles in a straight channel through which fluid flows with a Poiseuille pattern of flow. The immersed boundary method based on feedback force is adopted for the current work. The equilibrium positions and migration times for circular, elliptical, rectangular, square, and biconcave particles are studied and presented. The cases of neutral and massive (high ratio of particle density to fluid density) particles are presented, and in both scenarios the biconcave particle attains its equilibrium position closest to the bottom wall and the elliptical particle acquires its equilibrium position closest to the channel center. Also, the migration time is highest for the biconcave particle, whereas it is lowest for the rectangular particle. © 2023 Wiley-VCH GmbH.