Academic literature on the topic 'Particle-wall collision model'
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Journal articles on the topic "Particle-wall collision model"
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Lin, J. H., and K. C. Chang. "Particle Dispersion Simulation in Turbulent Flow Due to Particle-Particle and Particle-Wall Collisions." Journal of Mechanics 32, no. 2 (August 19, 2015): 237–44. http://dx.doi.org/10.1017/jmech.2015.63.
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AbstractSimulation of the 3-D, fully developed turbulent channel flows laden with various mass loading ratios of particles is made using an Eulerian-Lagrangian approach in which the carrier-fluid flow field is solved with a low-Reynolds-number k-ε turbulence model while the deterministic Lagrangian method together with binary-collision hard-sphere model is applied for the solution of particle motion. Effects of inter-particle collisions and particle-wall collisions under different extents of wall roughness on particle dispersion are addressed in the study. A cost-effective searching algorithm of collision pair among particles is developed. It is found that the effects of inter-particle collisions on particle dispersion cannot be negligible when the ratio of the mean free time of particle to the mean particle relaxation time of particle is less or equal to O(10). In addition, the wall roughness extent plays an important role in the simulation of particle-wall collisions particularly for cases with small mass loading ratios.
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ARDEKANI, A. M., and R. H. RANGEL. "Numerical investigation of particle–particle and particle–wall collisions in a viscous fluid." Journal of Fluid Mechanics 596 (January 17, 2008): 437–66. http://dx.doi.org/10.1017/s0022112007009688.
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The dynamics of particle–particle collisions and the bouncing motion of a particle colliding with a wall in a viscous fluid is numerically investigated. The dependence of the effective coefficient of restitution on the Stokes number and surface roughness is analysed. A distributed Lagrange multiplier-based computational method in a solid–fluid system is developed and an efficient method for predicting the collision between particles is presented. A comparison between this method and previous collision strategies shows that the present approach has some significant advantages over them. Comparison of the present methodology with experimental studies for the bouncing motion of a spherical particle onto a wall shows very good agreement and validates the collision model. Finally, the effect of the coefficient of restitution for a dry collision on the vortex dynamics associated with this problem is discussed.
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Derevich, I. V. "Probabilistic model of a particle-rough wall collision." Journal of Applied Mechanics and Technical Physics 40, no. 5 (September 1999): 989–94. http://dx.doi.org/10.1007/bf02468487.
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Zenit, Roberto, and Melany L. Hunt. "Mechanics of Immersed Particle Collisions." Journal of Fluids Engineering 121, no. 1 (March 1, 1999): 179–84. http://dx.doi.org/10.1115/1.2821999.
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The present work investigates the mechanics of particle collisions submerged in a liquid using a simple pendulum experiment. Particle trajectories for different particles in water are measured using a high-speed digital camera and the magnitude of the collision is recorded using a high-frequency-response pressure transducer at the colliding surface. The particle deceleration occurs at distances less than half a particle diameter from the wall. The measured collision impulse increases with impact velocity and particle mass. Comparisons are drawn between the measured pressures and the predictions of basic impact mechanics assuming a perfectly elastic collision. A control-volume model is proposed that accounts for the fluid inertia and viscosity. When a particle approaches a planar surface or another particle, the fluid is squeezed prior to contact, reducing the initial kinetic energy and decelerating the particle. The pressure profile is integrated over the surface of the particle to obtain a force that is a function of the initial particle Reynolds number, Reo, and the ratio of the densities of the particle and fluid phases, ρp/ρf. The model predicts a critical Stokes number at which the particle reaches the wall with zero velocity. Comparisons between the proposed model and the experimental measurements show qualitative agreement.
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Lin, Jian-Hung, and Keh-Chin Chang. "A Modeling Study on Particle Dispersion in Wall-Bounded Turbulent Flows." Advances in Applied Mathematics and Mechanics 6, no. 06 (December 2014): 764–82. http://dx.doi.org/10.4208/aamm.2014.m533.
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AbstractThree physical mechanisms which may affect dispersion of particle’s motion in wall-bounded turbulent flows, including the effects of turbulence, wall roughness in particle-wall collisions, and inter-particle collisions, are numerically investigated in this study. Parametric studies with different wall roughness extents and with different mass loading ratios of particles are performed in fully developed channel flows with the Eulerian-Lagrangian approach. A low-Reynolds-numberk–εturbulence model is applied for the solution of the carrier-flow field, while the deterministic Lagrangian method together with binary-collision hard-sphere model is applied for the solution of particle motion. It is shown that the mechanism of inter-particle collisions should be taken into account in the modeling except for the flows laden with sufficiently low mass loading ratios of particles. Influences of wall roughness on particle dispersion due to particle-wall collisions are found to be considerable in the bounded particle–laden flow. Since the investigated particles are associated with large Stokes numbers, i.e., larger thanO(1), in the test problem, the effects of turbulence on particle dispersion are much less considerable, as expected, in comparison with another two physical mechanisms investigated in the study.
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Kempe, Tobias, and Jochen Fröhlich. "Collision modelling for the interface-resolved simulation of spherical particles in viscous fluids." Journal of Fluid Mechanics 709 (August 23, 2012): 445–89. http://dx.doi.org/10.1017/jfm.2012.343.
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AbstractThe paper presents a model for particle–particle and particle–wall collisions during interface-resolving numerical simulations of particle-laden flows. The accurate modelling of collisions in this framework is challenging due to methodological problems generated by interface approach and contact as well as due to the greatly different time scales involved. To cope with this situation, multiscale modelling approaches are introduced avoiding excessive local grid refinement during surface approach and time step reduction during the surface contact. A new adaptive model for the normal forces in the phase of ‘dry contact’ is proposed, stretching the collision process in time to match the time step of the fluid solver. This yields a physically sound and robust collision model with modified stiffness and damping determined by an optimization scheme. Furthermore, the model is supplemented with a new approach for modelling the tangential force during oblique collisions which is based on two material parameters: a critical impact angle separating rolling from sliding and the friction coefficient for the sliding motion. The resulting new model is termed the adaptive collision model (ACM). All proposed sub-models only contain physical parameters, and virtually no numerical parameters requiring adjustment or tuning. The new model is implemented in the framework of an immersed boundary method but is applicable with any spatial and temporal discretization. Detailed validation against experimental data was performed so that a general and versatile model for arbitrary collisions of spherical particles in viscous fluids is now available.
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Zhang, Xia, and Lixing Zhou. "A second-order moment particle–wall collision model accounting for the wall roughness." Powder Technology 159, no. 2 (November 2005): 111–20. http://dx.doi.org/10.1016/j.powtec.2005.07.005.
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Cheng, Jiarui, Yihua Dou, Ningsheng Zhang, Zhen Li, and Zhiguo Wang. "A New Method for Predicting Erosion Damage of Suddenly Contracted Pipe Impacted by Particle Cluster via CFD-DEM." Materials 11, no. 10 (September 28, 2018): 1858. http://dx.doi.org/10.3390/ma11101858.
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A numerical study on the erosion of particle clusters in an abrupt pipe was conducted by means of the combined computational fluid dynamics (CFD) and discrete element methods (DEM). Furthermore, a particle-wall extrusion model and a criterion for judging particle collision interference were developed to classify and calculate the erosion rate caused by different interparticle collision mechanisms in a cluster. Meanwhile, a full-scale pipe flow experiment was conducted to confirm the effect of a particle cluster on the erosion rate and to verify the calculated results. The reducing wall was made of super 13Cr stainless steel materials and the round ceramsite as an impact particle was 0.65 mm in diameter and 1850 kg/m3 in density. The results included an erosion depth, particle-wall contact parameters, and a velocity decay rate of colliding particles along the radial direction at the target surface. Subsequently, the effect of interparticle collision mechanisms on particle cluster erosion was discussed. The calculated results demonstrate that collision interference between particles during one cluster impact was more likely to appear on the surface with large particle impact angles. This collision process between the rebounded particles and the following particles not only consumed the kinetic energy but also changed the impact angle of the following particles.
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BOURGADE, JEAN-PIERRE. "A COUPLED SPHERICAL HARMONICS EXPANSION MODEL FOR CONFINED PARTICLES." Mathematical Models and Methods in Applied Sciences 14, no. 08 (August 2004): 1133–65. http://dx.doi.org/10.1142/s021820250400357x.
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Our goal in this paper is to derive from a kinetic setting a diffusion model for the transport of charged particles trapped in a surface potential. The so-obtained model is derived through a diffusion approximation, as we assume the thermalization to be governed by particle-wall collisions. In order to take into account the possible inelasticity of such collisions, we introduce a nonlocal (in energy) collision operator on the boundary. At the macroscopic scale, this results in a coupled (in energy) Spherical Harmonics Expansion (SHE) model. The model is both formally and rigorously derived from the kinetic equation, and existence is obtained as a by-product of the derivation.
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Gui, Nan, Xingtuan Yang, Jiyuan Tu, and Shengyao Jiang. "A generalized particle-to-wall collision model for non-spherical rigid particles." Advanced Powder Technology 27, no. 1 (January 2016): 154–63. http://dx.doi.org/10.1016/j.apt.2015.12.002.
Full textDissertations / Theses on the topic "Particle-wall collision model"
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Tian, Zhaofeng, and rmit tian@gmail com. "Numerical Modelling of Turbulent Gas-Particle Flow and Its Applications." RMIT University. Aerospace, Mechanical and Manufacturing Engineering, 2007. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080528.150211.
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The aim of this thesis is three-fold: i) to investigate the performance of both the Eulerian-Lagrangian model and the Eulerian-Eulerian model to simulate the turbulent gas-particle flow; ii) to investigate the indoor airflows and contaminant particle flows using the Eulerian-Lagrangian model; iii) to develop and validate particle-wall collision models and a wall roughness model for the Eulerian-Lagrangian model and to utilize these models to investigate the effects of wall roughness on the particle flows. Firstly, the Eulerian-Lagrangian model in the software package FLUENT (FLUENT Inc.) and the Eulerian-Eulerian model in an in-house research code were employed to simulate the gas-particle flows. The validation against the measurement for two-phase flow over backward facing step and in a 90-degree bend revealed that both CFD approaches provide reasonably good prediction for both the gas and particle phases. Then, the Eulerian-Lagrangian model was employed to investigate the indoor airflows and contaminant particle concentration in two geometrically different rooms. For the first room configuration, the performances of three turbulence models for simulating indoor airflow were evaluated and validated against the measured air phase velocity data. All the three turbulence models provided good prediction of the air phase velocity, while the Large Eddy Simulation (LES) model base on the Renormalization Group theory (RNG) provided the best agreement with the measurements. As well, the RNG LES model is able to provide the instantaneous air velocity and turbulence that are required for the evaluation and design of the ventilation system. In the other two-zone ventilated room configuration, contaminant particle concentration decay within the room was simulated and validated against the experimental data using the RNG LES model together with the Lagrangian model. The numerical results revealed that the particle-wall coll ision model has a considerable effect on the particle concentration prediction in the room. This research culminates with the development and implementation of particle-wall collision models and a stochastic wall roughness model in the Eulerian-Lagrangian model. This Eulerian-Lagrangian model was therefore used to simulate the gas-particle flow over an in-line tube bank. The numerical predictions showed that the wall roughness has a considerable effect by altering the rebounding behaviours of the large particles and consequently affecting the particles motion downstream along the in-line tube bank and particle impact frequency on the tubes. Also, the results demonstrated that for the large particles the particle phase velocity fluctuations are not influenced by the gas-phase fluctuations, but are predominantly determined by the particle-wall collision. For small particles, the influence of particle-wall collisions on the particle fluctuations can be neglected. Then, the effects of wall roughness on the gas-particle flow in a two-dimensional 90-degree bend were investigated. It was found that the wa ll roughness considerably altered the rebounding behaviours of particles by significantly reducing the 'particle free zone' and smoothing the particle number density profiles. The particle mean velocities were reduced and the particle fluctuating velocities were increased when taking into consideration the wall roughness, since the wall roughness produced greater randomness in the particle rebound velocities and trajectories.
Conference papers on the topic "Particle-wall collision model"
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Zhang, X., and L. X. Zhou. "Simulation of Gas-Particle Channel Flows Using a Two-Fluid Particle-Wall Collision Model Accounting for Wall Roughness." In ASME/JSME 2003 4th Joint Fluids Summer Engineering Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/fedsm2003-45750.
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A two-fluid particle-wall collision model accounting for wall roughness is proposed. It accounts for the effects of wall friction, restitution, in particular the wall roughness, and hence the redistribution of particle Reynolds stresses in different directions at the wall, the absorption of turbulent kinetic energy from the kinetic energy of mean motion at the wall and the attenuation of particle motion by the wall. It gives the effect of wall roughness on the particle turbulence. The proposed model is applied to simulate gas-particle horizontal channel flows and is validated using PDPA measurement results. It is shown that presently used zero-gradient boundary conditions and other collision models of particle phase might give false results.
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Feng, Zhi-Gang, Efstathis E. Michaelides, and Shaolin Mao. "Simulation of Particle-Wall Collisions in a Viscous Fluid Using a Resolved Discrete Particle Method." In ASME 2010 3rd Joint US-European Fluids Engineering Summer Meeting collocated with 8th International Conference on Nanochannels, Microchannels, and Minichannels. ASMEDC, 2010. http://dx.doi.org/10.1115/fedsm-icnmm2010-30268.
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The process of particle-wall collisions is very important in understanding and determining the fluid-particle behavior, especially near walls. Detailed information on particle-wall collisions can provide insight on the formulation of appropriate boundary conditions of the particulate phases in two-fluid models. We have developed a three-dimensional Resolved Discrete Particle Method (RDPM) that is capable of meaningfully handling particle-wall collisions in a viscous fluid. This numerical method makes use of a Finite-Difference method in combination with the Immersed Boundary (IB) method for treating the particulate phase. A regular Eulerian grid is used to solve the modified momentum equations in the entire flow region. In the region that is occupied by the solid particles, a second particle-based Lagrangian grid is used, and a force density function is introduced to represent the momentum interactions between particle and fluid. We have used this numerical method to study both the central and oblique impact of a spherical particle with a wall in a viscous fluid. The particles are allowed to move in the fluid until they collide with the solid wall. The collision force on the particle is modeled by a soft-sphere collision scheme with a linear spring-dashpot system. The hydrodynamic force on the particle is solved directly from the RDPM. By following the trajectories of a particle, we investigate the effect of the collision model parameters to the dynamics of a particle close to the wall. We report in this paper the rebound velocity of the particle, the coefficient of restitution, and the particle slip velocity at the wall when a variety of different soft-sphere collision parameters are used.
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Arboleda, Brian Quintero, Zeeshan Qadir, Martin Sommerfeld, and Santiago Lain Beatove. "Modelling the Wall Collision of Regular Non-Spherical Particles and Experimental Validation." In ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting collocated with the ASME 2014 12th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fedsm2014-21610.
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The importance of numerical calculations (CFD) for supporting the optimization and lay-out of industrial processes involving multiphase flows is continuously increasing. Numerous processes in powder technology involve wall-bounded gas-solid flows where wall collisions essentially affect the process performance. In modelling the particle wall-collision process in the frame of numerical computations the general assumption is that the particles are spherical. However, in most practical situations one is dealing with irregular non-spherical particles or particles with a certain shape, such as granulates or fibers. In the case of non-spherical particle-wall collisions in confined flows, additional parameters such as roughness, particle shape and orientation play an important role and may strongly affect the transport behavior. The change of linear and angular velocity of the particle depends on these parameters, specifically the orientation and the radius of impact of the particles. In order to improve the non-spherical particle-wall understanding and modeling, in this work regular non-spherical particle-wall collisions in three dimensions are studied experimentally and computationally. For that purpose, cylindrical particles impacting a smooth wall at different angles are used. Single particle motion is tracked in space solving for both the translational and the rotational motion whereby the orientation of the non-spherical particle is obtained through the Euler angles and the Euler parameters. Once the particle touches the wall, the change of translational and angular velocity is determined by the non-spherical particle wall collision model. Experiments are made by shooting cylindrical non-spherical particles against a smooth plane wall at various impact angles and velocities. The collision event is recorded by two perpendicular arranged high-speed cameras. The experimental velocities obtained are used for validating the model.
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Breugem, Wim-Paul. "A Combined Soft-Sphere Collision/Immersed Boundary Method for Resolved Simulations of Particulate Flows." In ASME 2010 3rd Joint US-European Fluids Engineering Summer Meeting collocated with 8th International Conference on Nanochannels, Microchannels, and Minichannels. ASMEDC, 2010. http://dx.doi.org/10.1115/fedsm-icnmm2010-30634.
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A second-order accurate and efficient Immersed Boundary Method (IBM) has been developed for simulating particle-laden flows. Recently, this method has been combined with a soft-sphere collision model to accommodate inter-particle and particle-wall collisions. Details of the collision model are given. Results are shown from a lubrication study of non-touching particles at close distance from each other. The numerical results for the drag force acting on the particles agree well with exact solutions, except when the gap width between the particles becomes significantly smaller than the numerical grid spacing. For very small gap width, lubrication force corrections are proposed for the normal approach between particles based on asymptotic analytical solutions. Results are presented from a numerical study of sphere-wall collisions in a viscous fluid. The simulated behavior of the coefficient of restitution as function of the Stokes number based on the particle impact velocity, is in good agreement with experimental data.
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Singh, Sukhjinder, and Danesh Tafti. "Predicting the Coefficient of Restitution for Particle Wall Collisions in Gas Turbine Components." In ASME Turbo Expo 2013: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/gt2013-95623.
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Jet engines often operate under hostile conditions and are increasingly exposed to fine particulate matter such as sand, ash and dirt. Large amounts of fine particulate ingestion, sand in particular, can damage different engine components through deposition and erosion. The extent of damage depends on the particle-wall interaction, which is further governed by particle velocity, impact angle, particle size, particle material, target material and target surface roughness. Coefficient of restitution, which is the ratio of rebound velocity to impact velocity, encapsulates the effect of all the energy losses occurring during a collision. The current work presents a new model which predicts the energy losses and hence coefficient of restitution for a particle-wall collision. The current work combines elastic plastic deformation and adhesion theories of particle-wall interaction. Plastic deformation losses and adhesion losses are calculated separately based on impact parameters: impact velocity, impact angle, particle/wall material properties. These losses combine together to give the net energy loss during a collision and hence coefficient of restitution. The main objective of this study is to develop a collision model for sand particle interaction in gas turbine components, so the results are compared with available experimental data on coefficient of restitution for sand particles. The coefficient of restitution predictions are also compared with existing experimental data on a wide range of particle sizes and materials. Model predictions are found to be in good agreement with experiments.
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Mohaghegh, Fazlolah, and H. S. Udaykumar. "A Simplified Model for the Normal Collision of Arbitrary Shape Particles in a Viscous Flow." In ASME 2017 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/fedsm2017-69366.
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Modeling collision of finite size arbitrarily shaped particles is a tedious task because of difficulties in finding the collision parameter for the non-spherical particles. These parameters include the contact point, direction of the collision force and the collision forces and moments. In this paper a new collision algorithm is proposed to simulate collision of arbitrary shape particles to tackle flows containing a large number of particles. A pseudo-potential function is defined to quantify the collision parameters. This potential is defined based on the distance from the particle interface using either level set method or an analytical representation. With this definition, we can find the direction of collision forces and the amount of overlapping during the collision course. The collision forces are applied through a spring with a coefficient defined based on the collision course. In order to apply the damping, after the maximum collision course is achieved a spring with a lower stiffness in devised to achieve the desired bounce velocity. The results are validated for a spherical particle colliding with a wall. Then we show the capability of the model in simulation of collision of non-spherical particles with a wall. The new collision method not only is simple to implement but also it is applicable for any particle shape.
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Georgiou, D. P., and G. Paleos. "The Particle-Wall, Normal-Impact Collision Coefficient in the Presence of a Liquid Film." In ASME 1990 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1990. http://dx.doi.org/10.1115/90-gt-168.
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The turbine blades of Gas Turbines operating with “dirty” fuels are sometimes covered by a very thin liquid film, which originates from the condensation of the alkalic sulfates (mainly) in the flue gases. These films may influence drastically the collision coefficient of the impinging (ash) particles. This, in turn, influences the future trajectories of these particles and their adhesive properties, especially in the rotor blades where the Coriolis aceleration becomes a significant factor in the particle kinetic energy absorption process. The study reports on the capture film height and the variation of the collision coefficient with the film height. The experimental conditions correspond to those encountered in rotor blades, where the surface tension, the wave-making process and the boyancy all contribute to this energy absorption. The results indicate that the model based on the interaction of these factors gives a goodexplanation of the energy absorption process, except for the very thin height where particle apparent mass effects dominate the process.
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Kobayashi, Tomonari, Naoki Shimada, and Toshitsugu Tanaka. "DEM-CFD Coupling Simulation of Fluidized Behavior of Geldart’s Group A Particles: A Contact Force Model for Expressing Adhesion Force." In ASME-JSME-KSME 2011 Joint Fluids Engineering Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/ajk2011-12011.
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A discrete particle model for flows of Group A particles in Geldart’s classification was studied. In general, Group A particles are fine and light, so that the adhesion force has a strong effect on their fluidization behavior. At first, interparticle adhesion force of Group A particle was measured. The DEM-CFD coupling simulation with the measured adhesion force was performed, and the simulated results were compared with experimental data about a small scale fluidized bed for verification of the simulation. It was found from the results that there were considerable differences between their flow patterns. In order to reveal the cause of the differences, we investigated the effect of the contact force model with adhesion force on the motion of a single particle colliding with a wall. Then, we focused on the critical relative velocity of particle before collision that the particle kept in contact by the adhesion force, and discussed about the correlation of key parameters in the contact force model. From the analysis on the particle-wall collision process, it is found that the spring constant used in the DEM model has a large effect on the particle’s sticking behavior on the wall. The dynamic adhesion force model is proposed based on the present analytical investigation, and it is shown that the present model well expresses the experimental Group A particle bed fluidization behavior.
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Agrawal, Madhusuden, Ahmadreza Haghnegahdar, and Rahul Bharadwaj. "Improved Prediction of Sand Erosion by Accurate Particle Shape Representation in CFD-DEM Modelling." In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/206122-ms.
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Abstract Predicting accurate erosion rate due to sand particles in oil and gas production is important for maintaining safe and reliable operations while maximizing output efficiency. Computational Fluid Dynamic (CFD) is a powerful tool for erosion prediction as it provides detailed erosion pattern in complex geometry. In an effort to improve accuracy of erosion prediction, this paper proposes an algorithm to accurately represent particle shape in CFD erosion simulation through coupling with Discrete Element Method (DEM) for non-spherical shape particles. The fluid motions are predicted by CFD and the particle movements (including particle-particle and particle-wall collisions) and fluid-particle interaction are calculated using DEM. It is widely known that sand particles are of finite volume with a non-spherical shape, accurate representation of sand particles is important in CFD modelling for accurate prediction of erosion rate. Traditional CFD approach usages lagrangian tracking of sand particles through Discrete Phase Model (DPM), where a particle is assumed as a point mass for the calculation of trajectory and particle-wall interaction. Particle impact velocity and impact angle are important parameter in determining erosion. Assumption of point mass in DPM approach, will not capture particle-wall interaction accurately especially when particles are of non-spherical in shape. In additional, DPM approach ignores particle-particle interactions. This can adversary affect the accuracy of erosion predictions. Integrating non-spherical DEM collision algorithm with CFD erosion simulation, will overcome these limitations and improve erosion predictions. Benefits of this CFD-DEM erosion modelling was demonstrated for gas-solid flow in a 2" pipework which consists of out-of-plane elbows in series and blind-tees. Experimental dataset [1] for erosion pattern on each elbow was used to validate CFD predictions. Three different erosion CFD simulations were performed, traditional DPM based CFD simulation, CFD-DEM simulation for spherical shape particles and CFD-DEM simulation for non-spherical shape particles. CFD-DEM coupled simulations clearly show an improvement on erosion predictions compared to DPM based CFD simulation. Effect of non-spherical shape on rebound angle during particle-wall collision is captured accurately in CFD-DEM simulation. CFD-DEM simulation using non-spherical particle, was able to predict erosion pattern closer to experimental observations. This paper will demonstrate an increase in accuracy of sand erosion prediction by integrating DEM collision algorithm in CFD modelling. The prediction results of elbow erosion subject to a condition of dilute gas-particle flow are validated against experimental data. Improved prediction of erosion risk will increase the safety and reliability of oil & gas operations, while maximizing output efficiency.
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Narayanan, Chidambaram, and Djamel Lakehal. "Four-Way Coupling of Dense Particle Beds of Black Powder in Turbulent Pipe Flows." In ASME 2010 3rd Joint US-European Fluids Engineering Summer Meeting collocated with 8th International Conference on Nanochannels, Microchannels, and Minichannels. ASMEDC, 2010. http://dx.doi.org/10.1115/fedsm-icnmm2010-30137.
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The modeling of particle deposition and transport in pipes is one of the most challenging problems in multiphase flow, because the underlying physics is multi-faceted and complex, including turbulence of the carrier phase, particle-turbulence interaction, particle-wall interactions, particle-particle interactions, two-way and four-way couplings, particle agglomeration, deposition and re-suspension. We will discuss these issues and present new routes for the modeling of particle collision stress. Practical examples like black powder deposition and transport in gas pipelines will be presented and discussed. The model employed is based on dense-particle formulation accounting for particle-turbulence interaction, particle-wall interactions, particle-particle interactions via a collision stress. The model solves the governing equations of the fluid phase using a continuum model and those of the particle phase using a Lagrangian model. Inter-particle interactions for dense particle flows with high volume fractions (from 1% to close packing ∼60%) have been accounted for by mapping particle properties to an Eulerian grid and then mapping back computed stress tensors to particle positions. Turbulence within the continuum gas field was simulated using the V-LES (Very Large-Eddy Simulation) and full LES, which provides sufficient flow unsteadiness needed to disperse the particles and move the deposited bed.