Conference Papers
Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/28506
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Item Mixing in Oscillating Lid Driven Cavity—A Numerical Study(Springer Science and Business Media Deutschland GmbH, 2021) Neeraj, M.P.; Maniyeri, R.The mixing problems are highly important to be dealt with in fluid mechanics. In the present work mixing in a lid driven cavity with constant top wall velocity and oscillating top wall velocity is addressed. The staggered grid system is used and discretization of continuity equation, Navier–Stokes equations and concentration equation are done using Finite Volume Method. The Euler Explicit scheme is used for solving the numerical problem. Firstly, the developed computational model is validated with that of other researcher’s results for the case of constant top wall motion. Then the simulation is done for oscillating top wall for a Reynolds number of 100 and two amplitudes. The results in both cases are compared. © 2021, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.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 Numerical study of two particle migration in a stepped channel(American Institute of Physics Inc., 2023) Neeraj, M.P.; Maniyeri, R.Two particle migration in a stepped channel is analyzed by the aid of finite volume immersed boundary method (based on feedback forcing scheme). The particles seem to travel passing the step at the center and reach the equilibrium position. The density ratio and depth of step are varied to observe the behaviour of migration time and equilibrium position. The buoyant force increases with rise in density ratio and this will bring the particle equilibrium position closer to bottom wall for larger density ratios. It should be also noted that the migration time will increase with the density ratio due to enhancement in buoyant force. When the depth of step rises then the equilibrium position is moved towards bottom wall. On the other part, the migration time increases with depth of step. The critical depth corresponds to the lowest migration time is 0.15 for the present study. © 2023 AIP Publishing LLC.Item Lateral Migration of Three Particles Through a Slit—An Immersed Boundary Computational Analysis(Springer Science and Business Media Deutschland GmbH, 2024) Neeraj, M.P.; Maniyeri, R.The current work focuses on the migration of three particles in Poiseuille flow through a slit microchannel. The immersed boundary finite volume methodology based on feedback forcing scheme is used to build the computational model for the analysis of particle migration through slit. Three rigid non-neutrally buoyant cylindrical particles are released from same lateral position in a channel of 20 × 1 dimension. It is observed that the particles travel through the slit and attain equilibrium position at the center of the channel. Further, the influence of slit gap and angle on the equilibrium position and residence time is studied. It is interesting to see that the equilibrium position stays unaffected by the changes in both of the above mentioned parameters. However, the residence time increases with the slit gap. It should be also noted that the migration time is the lowest for a slit angle of π/2. © 2024, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.