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Sankaran Sundaresan - One of the best experts on this subject based on the ideXlab platform.
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lattice boltzmann simulations of low reynolds number flow past Fluidized spheres effect of stokes number on drag force
Journal of Fluid Mechanics, 2016Co-Authors: Gregory J. Rubinstein, J J Derksen, Sankaran SundaresanAbstract:In a Fluidized bed, the drag force acts to oppose the downward force of gravity on a Particle, and thus provides the main mechanism for Fluidization. Drag models that are employed in large-scale simulations of Fluidized beds are typically based on either fixed-Particle beds or the sedimentation of Particles in liquids. In low-Reynolds-number ( ) systems, these two types of Fluidized beds represent the limits of high Stokes number ( ) and low , respectively. In this work, the Fluid–Particle drag behaviour of these two regimes is bridged by investigating the effect of on the drag force in low- systems. This study is conducted using fully resolved lattice Boltzmann simulations of a system composed of Fluid and monodisperse spherical Particles. In these simulations, the Particles are free to translate and rotate based on the effects of the surrounding Fluid. Through this work, three distinct regimes in the characteristics of the Fluid–Particle drag force are observed: low, intermediate and high . It is found that, in the low- regime, a decrease in results in a reduction in the Fluid–Particle drag. Based on the simulation results, a new drag relation is proposed, which is, unlike previous models, dependent on .
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Lattice Boltzmann simulations of low-Reynolds-number flow past Fluidized spheres: effect of Stokes number on drag force
Journal of Fluid Mechanics, 2016Co-Authors: Gregory J. Rubinstein, Jos Derksen, Sankaran SundaresanAbstract:In a Fluidized bed, the drag force acts to oppose the downward force of gravity on a Particle, and thus provides the main mechanism for Fluidization. Drag models that are employed in large-scale simulations of Fluidized beds are typically based on either fixed-Particle beds or the sedimentation of Particles in liquids. In low-Reynolds-number ( $Re$ ) systems, these two types of Fluidized beds represent the limits of high Stokes number ( $St$ ) and low $St$ , respectively. In this work, the Fluid–Particle drag behaviour of these two regimes is bridged by investigating the effect of $St$ on the drag force in low- $Re$ systems. This study is conducted using fully resolved lattice Boltzmann simulations of a system composed of Fluid and monodisperse spherical Particles. In these simulations, the Particles are free to translate and rotate based on the effects of the surrounding Fluid. Through this work, three distinct regimes in the characteristics of the Fluid–Particle drag force are observed: low, intermediate and high $St$ . It is found that, in the low- $Re$ regime, a decrease in $St$ results in a reduction in the Fluid–Particle drag. Based on the simulation results, a new drag relation is proposed, which is, unlike previous models, dependent on $St$ .
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validation of filtered two Fluid models for gas Particle flows against experimental data from bubbling Fluidized bed
Powder Technology, 2015Co-Authors: Shailesh S Ozarkar, Fernando Eduardo Milioli, Christian C Milioli, Shuyan Wang, Sankaran SundaresanAbstract:Abstract Predictions of simulations based on filtered Two-Fluid Models (TFMs) with constitutive relations for filtered Fluid–Particle drag coefficient and filtered stresses proposed by Igci and Sundaresan [Ind. Eng. Chem. Res. 50 (2011) 13190–13201] and Milioli et al. [AIChE J. 59 (2013) 3265–3275] were compared against experimental data from a bubbling Fluidized bed challenge problem put forward by the National Energy Technology Laboratory and Particulate Solids Research Inc. It is found that the most important correction to filtered models is a modification to the drag, and filtered stresses play a secondary role at best. As expected, coarse grid simulations using the kinetic-theory based TFM over-predicted the gas–Particle drag force, yielding unphysical bed expansion. The filtered Fluid–Particle drag model proposed by Igci and Sundaresan that classifies the inhomogeneity in sub-filter scale flow structures using filter size and filtered Particle volume fraction as markers also predicted unphysical bed expansion. Refined filtered drag models proposed by Milioli et al. based on filtered Fluid–Particle slip velocity as an additional marker led to good agreement with experimental data on bed expansion and the time-averaged gas pressure gradient. It was also observed that inadequate grid resolution in the region between gas distributor and the adjacent cylindrical wall of the test unit could lead to spurious asymmetric gas–Particle flow predictions. With the inclusion of adequate inflation layer elements in that region, flow predictions became nearly symmetric with little to no effect on bed expansion predictions. However, it dramatically and qualitatively altered the details of gas–Particle structures in the bed.
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Fluid Particle drag in inertial polydisperse gas solid suspensions
Aiche Journal, 2009Co-Authors: William Holloway, Xiaolong Yin, Sankaran SundaresanAbstract:In this article, we extend the low Reynolds number Fluid-Particle drag relation proposed by Yin and Sundaresan for polydisperse systems to include the effect of moderate Fluid inertia. The proposed model captures the Fluid-Particle drag results obtained from lattice-Boltzmann simulations of bidisperse and ternary suspensions at Particle mixture Reynolds numbers ranging from 0 � Remix � 40, over a Particle volume fraction range of 0.2 � f � 0.4, volume fraction ratios of 1 � fi/fj � 3, and Particle diameter ratios of 1 � di/dj � 2.5. V C 2009 American Institute of Chemical Engineers AIChE J, 56: 1995–2004, 2010
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Fluid Particle drag in low reynolds number polydisperse gas solid suspensions
Aiche Journal, 2009Co-Authors: Xiaolong Yin, Sankaran SundaresanAbstract:Lattice-Boltzmann simulations of low-Reynolds-number Fluid flow in bidisperse fixed beds and suspensions with Particle–Particle relative motions have been performed. The Particles are spherical and are intimately mixed. The total volume fraction of the suspension was varied between 0.1 and 0.4, the volume fraction ratio /1//2 from 1:1 to 1:6, and the Particle size ratio d1/d2 from 1:1.5 to 1:4. A drag law with improved accuracy has been established for bidisperse fixed beds. For suspensions with Particle– Particle relative motions, the hydrodynamic Particle–Particle drag representing the momentum transfer between Particle species through hydrodynamic interaction is found to be an important contribution to the net Fluid-Particle drag. It has a logarithmic dependence on the lubrication cutoff distance and can be fit as the harmonic mean of the drag forces in bidisperse fixed beds. The proposed drag laws for bidisperse fixed beds and suspensions are generalized to polydisperse suspensions with three or more Particle species. V C 2009 American Institute of Chemical Engineers AIChE J, 55: 1352–1368, 2009
Jam Hans Kuipers - One of the best experts on this subject based on the ideXlab platform.
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direct numerical simulation of Fluid flow and mass transfer in dense Fluid Particle systems with surface reactions
Chemical Engineering Science, 2018Co-Authors: Saurish S Das, E A J F Peters, Jam Hans KuipersAbstract:Abstract In this paper, an efficient ghost-cell based immersed boundary method is introduced to perform direct numerical simulation (DNS) of mass transfer problems in particulate flows. The Fluid-solid coupling is achieved by implicit incorporation of the boundary conditions into the discretized momentum and species conservation equations of the Fluid phase. Taking the advantage of a second order quadratic interpolation scheme utilized in the reconstruction procedures, the unique feature of this ghost-cell based immersed boundary method is its capability to handle mixed boundary conditions at the exact position of the Particle surface as encountered in systems with interplay between surface reactions and diffusion. A fixed Eulerian grid is used to solve the conservation equations for the entire computational domain. Following a detailed verification of the method in the limiting case of unsteady molecular diffusion without convection, we apply our method to study Fluid-Particle mass transfer for flow around a single sphere and a dense stationary array consisting of hundreds of spheres over a range of Damkohler numbers.
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a combined experimental and simulation study of Fluid Particle heat transfer in dense arrays of stationary Particles
Chemical Engineering Science, 2017Co-Authors: Kay A Buist, N Niels G Deen, B J G H Backx, Jam Hans KuipersAbstract:A novel experimental technique is introduced to study Fluid-Particle heat transfer in dense arrays of stationary Particle. First a Constant Temperature Anemometer is reconfigured to a heat transfer probe. The thermal driving force is defined as the difference between the probe temperature and the initial Fluid temperature and well known in our system. Second an abacus-like structure is employed to accurately control the solids volume fraction. The solids fraction was varied between 0 and 0.6 with increments of 0.1. The Reynolds number varied between 0 and 800. This combination of approaches allows for a very well-defined system, that can be studied both experimentally and numerically, and as such can serve as a validation of heat transfer studies with Direct Numerical Simulations, in Fluid-Particle systems. A single Particle in unbounded flow, the effect of inter-Particle distance and shielding effects for an inline array of three spheres as well as semi-structured arrays of Particles are studied.
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direct numerical simulation of Fluid flow accompanied by coupled mass and heat transfer in dense Fluid Particle systems
Chemical Engineering Science, 2014Co-Authors: N Niels G Deen, Jam Hans KuipersAbstract:Abstract In this paper we report the extension of an earlier reported DNS method ( Deen et al., 2012 , Deen and Kuipers, 2013 ) based on a novel Immersed Boundary Method (IBM) which incorporates the Fluid–solid coupling at the level of the discrete field equations. The extended method is used to study coupled mass and heat transport in dense Fluid–Particle systems where the coupling arises as a consequence of an exothermal chemical reaction proceeding at the exterior surface of the Particles. Following a detailed verification (using an independent numerical technique) and validation (using established empirical correlations) we apply our DNS technique to study coupled mass and heat transfer in a dense Fluid–Particle system. In addition a comparison is made with results obtained from a simple one-dimensional (1D) heterogeneous reactor model which uses empirical closures for the Fluid–Particle mass and heat transfer coefficients. The main features of the complex transient temperature profiles obtained from our DNS agree quite well with the corresponding profiles obtained from the 1D heterogeneous reactor model.
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direct numerical simulation dns of mass momentum and heat transfer in dense Fluid Particle systems
Current opinion in chemical engineering, 2014Co-Authors: N Niels G Deen, Jam Hans KuipersAbstract:Direct Numerical Simulation (DNS) of complex multiphase flows is rapidly gaining attention. In this paper we explain the role of Direct Numerical Simulation (DNS) in the context of a multi-scale approach to model systems involving mass, momentum and heat transfer in dense Fluid-Particle systems. Following a brief description of the theoretical framework and the associated computational methods we present several illustrative results highlighting the power of DNS to generate detailed closures for Fluid-Particle interaction. Finally, several future challenges are indicated.
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direct numerical simulation of Fluid flow and mass transfer in dense Fluid Particle systems
Industrial & Engineering Chemistry Research, 2013Co-Authors: N Niels G Deen, Jam Hans KuipersAbstract:In this paper, a novel simulation technique is presented to perform direct numerical simulation (DNS) of Fluid flow and mass transfer in dense Fluid–Particle systems. The Fluid–solid coupling is achieved via direct (i.e., implicit) incorporation of the boundary condition (with a second-order method) at the surface of the Particles at the level of the discrete momentum and species conservation equations of the Fluid. A fixed (Eulerian) grid is utilized to solve the Navier–Stokes equations for the entire computational domain. Dissipative Particle–Particle and/or Particle–wall collisions are taken into account via a hard-sphere discrete Particle (DP) approach, using a three-parameter Particle–Particle interaction model that accounts for normal and tangential restitution, as well as tangential friction. Following the verification of our method using well-known empirical expressions for the Sherwood number, we apply our method to study Fluid–Particle mass transfer in dense multiParticle systems involving rando...
Philippe Villedieu - One of the best experts on this subject based on the ideXlab platform.
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monte carlo simulation of colliding Particles or coalescing droplets transported by a turbulent flow in the framework of a joint Fluid Particle pdf approach
International Journal of Multiphase Flow, 2015Co-Authors: Olivier Simonin, Pascal Fede, Philippe VilledieuAbstract:The aim of the paper is to introduce and validate a Monte-Carlo algorithm for the prediction of an ensemble of colliding solid Particles, or coalescing liquid droplets, suspended in a turbulent gas flow predicted by Reynolds Averaged Navier Stokes approach (RANS). The new algorithm is based on the direct discretization of the collision/coalescence kernel derived in the framework of a joint Fluid–Particle pdf approach proposed by Simonin et al. (2002). This approach allows to take into account correlations between colliding inertial Particle velocities induced by their interaction with the Fluid turbulence. Validation is performed by comparing the Monte-Carlo predictions with deterministic simulations of discrete solid Particles coupled with Direct Numerical Simulation (DPS/DNS), or Large Eddy Simulation (DPS/LES), where the collision/coalescence effects are treated in a deterministic way. Five cases are investigated: elastic monodisperse Particles, non-elastic monodisperse Particles, binary mixture of elastic Particles and binary mixture of elastic settling Particles in turbulent flow and finally coalescing droplets. The predictions using the new Monte-Carlo algorithm are in much better agreement with DPS/DNS results than the ones using the standard algorithm.
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a quadrature based moment method for dilute Fluid Particle flows
Journal of Computational Physics, 2008Co-Authors: Olivier Desjardins, Rodney O Fox, Philippe VilledieuAbstract:Gas-Particle and other dispersed-phase flows can be described by a kinetic equation containing terms for spatial transport, acceleration, and Particle processes (such as evaporation or collisions). In principle, the kinetic description is valid from the dilute (non-collisional) to the dense limit. However, its numerical solution in multi-dimensional systems is intractable due to the large number of independent variables. As an alternative, Lagrangian methods ''discretize'' the density function into ''parcels'' that are simulated using Monte-Carlo methods. While quite accurate, as in any statistical approach, Lagrangian methods require a relatively large number of parcels to control statistical noise, and thus are computationally expensive. A less costly alternative is to solve Eulerian transport equations for selected moments of the kinetic equation. However, it is well known that in the dilute limit Eulerian methods have great difficulty to describe correctly the moments as predicted by a Lagrangian method. Here a two-node quadrature-based Eulerian moment closure is developed and tested for the kinetic equation. It is shown that the method can successfully handle highly non-equilibrium flows (e.g. impinging Particle jets, jet crossing, Particle rebound off walls, finite Stokes number flows) that heretofore could not be treated accurately with the Eulerian approach.
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monte carlo simulation of colliding Particles in gas solid turbulent flows from a joint Fluid Particle pdf equation
ASME 2002 Joint U.S.-European Fluids Engineering Division Conference, 2002Co-Authors: Pascal Fede, Olivier Simonin, Philippe VilledieuAbstract:This paper is dedicated to Lagrangian approach for modelling Particle-Particle interactions in gas-solid turbulent flows. This approach is based on a joint Fluid-Particle pdf equation solved using Monte Carlo method which has been developed to take into account the correlation between colliding Particles induced by the Fluid. The modification of the turbulence by the Particles is not included in the simulations. The Lagrangian results are presented in comparison with LES simulations (Lavieville et al., 1995) and continuum model.Copyright © 2002 by ASME
N Niels G Deen - One of the best experts on this subject based on the ideXlab platform.
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a combined experimental and simulation study of Fluid Particle heat transfer in dense arrays of stationary Particles
Chemical Engineering Science, 2017Co-Authors: Kay A Buist, N Niels G Deen, B J G H Backx, Jam Hans KuipersAbstract:A novel experimental technique is introduced to study Fluid-Particle heat transfer in dense arrays of stationary Particle. First a Constant Temperature Anemometer is reconfigured to a heat transfer probe. The thermal driving force is defined as the difference between the probe temperature and the initial Fluid temperature and well known in our system. Second an abacus-like structure is employed to accurately control the solids volume fraction. The solids fraction was varied between 0 and 0.6 with increments of 0.1. The Reynolds number varied between 0 and 800. This combination of approaches allows for a very well-defined system, that can be studied both experimentally and numerically, and as such can serve as a validation of heat transfer studies with Direct Numerical Simulations, in Fluid-Particle systems. A single Particle in unbounded flow, the effect of inter-Particle distance and shielding effects for an inline array of three spheres as well as semi-structured arrays of Particles are studied.
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direct numerical simulation of Fluid flow accompanied by coupled mass and heat transfer in dense Fluid Particle systems
Chemical Engineering Science, 2014Co-Authors: N Niels G Deen, Jam Hans KuipersAbstract:Abstract In this paper we report the extension of an earlier reported DNS method ( Deen et al., 2012 , Deen and Kuipers, 2013 ) based on a novel Immersed Boundary Method (IBM) which incorporates the Fluid–solid coupling at the level of the discrete field equations. The extended method is used to study coupled mass and heat transport in dense Fluid–Particle systems where the coupling arises as a consequence of an exothermal chemical reaction proceeding at the exterior surface of the Particles. Following a detailed verification (using an independent numerical technique) and validation (using established empirical correlations) we apply our DNS technique to study coupled mass and heat transfer in a dense Fluid–Particle system. In addition a comparison is made with results obtained from a simple one-dimensional (1D) heterogeneous reactor model which uses empirical closures for the Fluid–Particle mass and heat transfer coefficients. The main features of the complex transient temperature profiles obtained from our DNS agree quite well with the corresponding profiles obtained from the 1D heterogeneous reactor model.
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direct numerical simulation dns of mass momentum and heat transfer in dense Fluid Particle systems
Current opinion in chemical engineering, 2014Co-Authors: N Niels G Deen, Jam Hans KuipersAbstract:Direct Numerical Simulation (DNS) of complex multiphase flows is rapidly gaining attention. In this paper we explain the role of Direct Numerical Simulation (DNS) in the context of a multi-scale approach to model systems involving mass, momentum and heat transfer in dense Fluid-Particle systems. Following a brief description of the theoretical framework and the associated computational methods we present several illustrative results highlighting the power of DNS to generate detailed closures for Fluid-Particle interaction. Finally, several future challenges are indicated.
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direct numerical simulation of Fluid flow and mass transfer in dense Fluid Particle systems
Industrial & Engineering Chemistry Research, 2013Co-Authors: N Niels G Deen, Jam Hans KuipersAbstract:In this paper, a novel simulation technique is presented to perform direct numerical simulation (DNS) of Fluid flow and mass transfer in dense Fluid–Particle systems. The Fluid–solid coupling is achieved via direct (i.e., implicit) incorporation of the boundary condition (with a second-order method) at the surface of the Particles at the level of the discrete momentum and species conservation equations of the Fluid. A fixed (Eulerian) grid is utilized to solve the Navier–Stokes equations for the entire computational domain. Dissipative Particle–Particle and/or Particle–wall collisions are taken into account via a hard-sphere discrete Particle (DP) approach, using a three-parameter Particle–Particle interaction model that accounts for normal and tangential restitution, as well as tangential friction. Following the verification of our method using well-known empirical expressions for the Sherwood number, we apply our method to study Fluid–Particle mass transfer in dense multiParticle systems involving rando...
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direct numerical simulation of flow and heat transfer in dense Fluid Particle systems
Chemical Engineering Science, 2012Co-Authors: N Niels G Deen, Shl Sebastian Kriebitzsch, Martin A Van Der Hoef, Jam Hans KuipersAbstract:Abstract In this paper a novel simulation technique is presented to perform Direct Numerical Simulation (DNS) of Fluid flow and heat transfer in dense Fluid–Particle systems. The unique feature of our Fluid–solid coupling technique is the direct (i.e., implicit) incorporation of the boundary condition (with a second-order method) at the surface of the Particles at the level of the discrete momentum and thermal energy equations of the Fluid. Contrary to lattice Boltzmann or other commonly used immersed boundary implementations, our method does not require using any effective diameter. A fixed (Eulerian) grid is utilized to solve the Navier–Stokes equations for the entire computational domain. Dissipative Particle–Particle and/or Particle-wall collisions are accounted via a hard sphere discrete Particle approach using a three-parameter Particle–Particle interaction model accounting for normal and tangential restitution and tangential friction. Following the detailed verification of the method several dense multi-Particle systems are studied in detail involving stationary arrays of Particles and Fluidized Particles.
Ambrose Nwora Anozie - One of the best experts on this subject based on the ideXlab platform.
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Prediction of sand kinematic pressure and Fluid-Particle interaction coefficient as means of preventing sand-induced corrosion in crude oil pipelines
Ain Shams Engineering Journal, 2019Co-Authors: Samuel Eshorame Sanni, Sam Sunday Adefila, Ambrose Nwora AnozieAbstract:Sand-induced corrosion and scaling of petroleum pipes is a serious situation that barely knows any solution by conventional or new methods of corrosion control. This is because, the mechanism behind sand corrosion and scaling of petroleum pipes is yet to be unravelled. Rather than avoid the situation, the integration of sand filters in petroleum lines also contribute to the problem. In this work, a three phase model was used to simulate upstream flow conditions where sand is produced alongside water and crude oil. The effects of Fluid-Particle interaction coefficient/forces and sand kinematic pressure, in relation to conditions that favour sand deposition, corrosion and scaling of petroleum pipes were determined. Based on the results, on a 2–3 h basis, periodic checks need be conducted at the 12–18 m points where sand kinematic pressures and interaction coefficients of the components require flow adjustments in order to avoid situations leading to pipeline wea
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Prediction of sand kinematic pressure and Fluid-Particle interaction coefficient as means of preventing sand-induced corrosion in crude oil pipelines
Elsevier, 2019Co-Authors: Samuel Eshorame Sanni, Sam Sunday Adefila, Ambrose Nwora AnozieAbstract:Sand-induced corrosion and scaling of petroleum pipes is a serious situation that barely knows any solution by conventional or new methods of corrosion control. This is because, the mechanism behind sand corrosion and scaling of petroleum pipes is yet to be unravelled. Rather than avoid the situation, the integration of sand filters in petroleum lines also contribute to the problem. In this work, a three phase model was used to simulate upstream flow conditions where sand is produced alongside water and crude oil. The effects of Fluid-Particle interaction coefficient/forces and sand kinematic pressure, in relation to conditions that favour sand deposition, corrosion and scaling of petroleum pipes were determined. Based on the results, on a 2–3 h basis, periodic checks need be conducted at the 12–18 m points where sand kinematic pressures and interaction coefficients of the components require flow adjustments in order to avoid situations leading to pipeline wear. Keywords: Interaction coefficients, Kinematic pressure, Sand deposition, Sand-induced corrosion, Three-phase mode