Academic literature on the topic 'Eulerian-granular model'
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Journal articles on the topic "Eulerian-granular model"
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Lee, T. G., and S. W. Shin. "DEVELOPMENT OF EULERIAN-GRANULAR MODEL FOR NUMERICAL SIMULATION MODEL OF PARTICULATE FLOW." Journal of computational fluids engineering 20, no. 2 (June 30, 2015): 46–51. http://dx.doi.org/10.6112/kscfe.2015.20.2.046.
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Wang, Jiao Jiao, Qiang Zhu, Fan Zhang, Da Quan Li, and You Feng He. "Investigation on Liquid Segregation during Rheo-Casting Process Based on Eulerian-Granular Multiphase Model." Solid State Phenomena 256 (September 2016): 113–18. http://dx.doi.org/10.4028/www.scientific.net/ssp.256.113.
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A crucial problem concerned with the semi-solid forming process is the liquid segregation phenomena during shape formation, especially for rheo-casting process. Liquid segregation occurs due to the separation phenomena of the solid grain and the liquid phase. In this work, using commercial finite element software, the liquid segregation during rheo-casting process was numerically investigated by Eulerian-granular multiphase model based on the comparable results of single phase model, Eulerian-granular two-phase and three-phase model, along with Eulerian-granular DDPM three-phase model. In the study, solid grains and liquid phases were regarded as rigid material and non-Newtonian fluid at microscale, separately. This validation was experimentally proved and also compared to the proposed relationship of power law, Herschel-Bulkley model with yield stress at macroscale.
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Wang, Chun, Guanlin Ye, Xiannan Meng, Yongqi Wang, and Chong Peng. "A Eulerian–Lagrangian Coupled Method for the Simulation of Submerged Granular Column Collapse." Journal of Marine Science and Engineering 9, no. 6 (June 3, 2021): 617. http://dx.doi.org/10.3390/jmse9060617.
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A two-fluid Eulerian–Lagrangian coupled model is developed to investigate the complex interactions between solid particles and the ambient water during the process of submerged granular column collapse. In this model, the water phase is considered to be a Newtonian fluid, whereas the granular column is modeled as an elastic–perfectly plastic material. The water flow field is calculated by the mesh-based Eulerian Finite Volume Method (FVM), with the free surface captured by the Volume-of-Fluid (VOF) technique. The large deformation of the granular material is simulated by the mesh-free, particle-based Lagrangian Smoothed Particle Hydrodynamics method (SPH). Information transfer between Eulerian nodes and Lagrangian particles is performed by the aid of the SPH interpolation function. Both dry and submerged granular column collapses are simulated with the proposed model. Experiments of the submerged cases are also conducted for comparison. Effects of dilatancy (compaction) of initially dense (loose) packing granular columns on the mixture dynamics are investigated to reveal the mechanisms of different flow regimes. Pore water pressure field and granular velocity field are in good agreement between our numerical results and experimental observations, which demonstrates the capability of the proposed Eulerian–Lagrangian coupled method in dealing with complex submerged water–granular mixture flows.
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Han, Xin Feng, Jian Long Li, and Ning Xu. "CFD Simulation of the Fluidized Bed Applied in the Synthesis of Benzene Series Organosilicon." Advanced Materials Research 753-755 (August 2013): 2663–66. http://dx.doi.org/10.4028/www.scientific.net/amr.753-755.2663.
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The mathematical model of gas-solid flow 2D fluidized bed was established. The CFD simulation was carried out with commercial software FLUENT6.3 by using Eulerian-Eulerian multiphase models, based on the kinetic theory of granular flow and PC-SIMPLE algorithm. In order to provide a basis on optimizing the operating conditions of the fluidized bed applied in benzene series organosilicon reactor, the processes of bubble formation, growth and disappearance under different cases were analyzed.
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Zhang, Yang, Changsong Wu, Xiaosi Zhou, Yuanming Hu, Yuan Wang, and Bin Yang. "A Numerical Study of Aeolian Sand Particle Flow Incorporating Granular Pseudofluid Optimization and Large Eddy Simulation." Atmosphere 11, no. 5 (April 29, 2020): 448. http://dx.doi.org/10.3390/atmos11050448.
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A numerical investigation of aeolian sand particle flow in atmospheric boundary layer is performed with a Eulerian–Eulerian granular pseudofluid model. In this model, the air turbulence is modelled with a large eddy simulation, and a kinetic–frictional constitutive model incorporating frictional stress and the kinetic theory of granular flow is applied to describe the interparticle movement. The simulated profiles of streamwise sand velocity and sand mass flux agree well with the reported experiments. The quantitative discrepancy between them occurs near the sand bed surface, which is due to the difference in sand sample, but also highlights the potential of the present model in addressing near-surface mass transport. The simulated profiles of turbulent root mean square (RMS) particle velocity suggest that the interparticle collision mainly account for the fluctuation of sand particle movement.
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Hilmee, M. I., Mohan Sinnathambi Chandra, Saravanan Karuppanan, M. Fadhil, and Mohd Rizal Lias. "Effects of Different Granular Viscosity Models on the Bubbling Fluidized Bed - A Numerical Approach." Applied Mechanics and Materials 393 (September 2013): 857–62. http://dx.doi.org/10.4028/www.scientific.net/amm.393.857.
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Kinetic Theory of Granular Flow (KTGF) has been successfully incorporated and widely implemented in the Eulerian simulation models in many multiphase cases. The KTGF theory involves many parameters and is applied in the multiphase simulation for the purpose of hydrodynamic properties modeling of the granular phase. This paper is focused on granular viscosity which is a parameter in the KTGF that incorporates three different viscosities arising from the inter-phase and intra phases interaction in a bubbling fluidized bed (BFB). The 2D BFB model of 0.2 m width and 0.8 m length having a 13-hole orifice plate has been modeled for this purpose. The model was constructed using Gambit software version 2.4.6 and then simulated using ANSYS Fluent version 14. Two models of granular viscosity, namely Syamlal-Obrien model and Gidaspow model, were compared based on its effect to the pressure drop and bed expansion of the BFB. The results depicted that the simulation based on Syamlal-Obrien model tends to produce larger bubbles and contributing to a higher pressure drop across the distributor plate as compared to the Gidaspow model.
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Wu, Ze-Xiang, Hui Ji, Jian Han, and Chuang Yu. "Numerical modelling of granular column collapse using coupled Eulerian–Lagrangian technique with critical state soil model." Engineering Computations 36, no. 7 (August 12, 2019): 2480–504. http://dx.doi.org/10.1108/ec-08-2018-0358.
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Purpose Current modellings of granular collapse are lack of considering the effect of soil density. This paper aims to present a numerical method to analyse the collapse of granular column based on the critical-state soil mechanics. Design/methodology/approach In the proposed method, a simple critical-state based constitutive model is first adopted and implemented into a finite element code using the coupled Eulerian–Lagrangian technique for large deformation analysis. Simulations of column collapse with various aspect ratios are then conducted for a given initial soil density. The effect of aspect ratio on the final size of deposit morphology, dynamical collapse profiles and the stable region is discussed comparing to experimental results. Moreover, complementary simulations with various initial soil densities on each aspect ratio are conducted. Findings Simulations show that a lower value of initial density leads to a lower final deposit height and a longer run-out distance. The simulated evolutions of kinetic energy and collapsing profile with time by the proposed numerical approach also show clearly a soil density-dependent collapse process. Practical implications To the end, this study can improve the understanding of column collapse in different aspect ratios and soil densities, and provide a computational tool for the analysis of real scale granular flow. Originality/value The originality of this paper is proposed in a numerical approach to model granular column collapse considering the influences of aspect ratio and initial void ratio. The proposed approach is based on the finite element platform with coupled Eulerian–Lagrangian technique for large deformation analysis and implementing the critical-state based model accounting for the effect of soil density.
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Favrie, N., and S. Gavrilyuk. "Dynamic compaction of granular materials." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 469, no. 2160 (December 8, 2013): 20130214. http://dx.doi.org/10.1098/rspa.2013.0214.
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An Eulerian hyperbolic multiphase flow model for dynamic and irreversible compaction of granular materials is constructed. The reversible model is first constructed on the basis of the classical Hertz theory. The irreversible model is then derived in accordance with the following two basic principles. First, the entropy inequality is satisfied by the model. Second, the corresponding ‘intergranular stress’ coming from elastic energy owing to contact between grains decreases in time (the granular media behave as Maxwell-type materials). The irreversible model admits an equilibrium state corresponding to von Mises-type yield limit. The yield limit depends on the volume fraction of the solid. The sound velocity at the yield surface is smaller than that in the reversible model. The last one is smaller than the sound velocity in the irreversible model. Such an embedded model structure assures a thermodynamically correct formulation of the model of granular materials. The model is validated on quasi-static experiments on loading–unloading cycles. The experimentally observed hysteresis phenomena were numerically confirmed with a good accuracy by the proposed model.
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Chen, Yu Lin, Qing Wang, Cong Cong Liu, and Jian Xin Ge. "Numerical Simulation of the Flow Characteristics of 35t/h Internally Circulating Fluidized Bed." Applied Mechanics and Materials 529 (June 2014): 272–76. http://dx.doi.org/10.4028/www.scientific.net/amm.529.272.
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The gas-solid flow characteristics of the 35t/h oil shale-combustion circulating fluidized bed boiler (Developed by Wangqing Longteng Energy Development Co., Ltd) was simulated using Eulerian-Eulerian model (EEM), which was based on the kinetic theory of granular. The distribution of particle volume fraction and the distribution of particle velocity revealed the mechanism of the internal recirculation flow of particles in the furnace. The simulation results provided a reference for the flow structure optimization of the inner circulating fluidized bed and the enlargement of the inner circulating fluidized bed boiler.
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Heng, J., T. H. New, and P. A. Wilson. "On the application of an Eulerian granular model towards dilute phase pneumatic conveying." Powder Technology 327 (March 2018): 456–66. http://dx.doi.org/10.1016/j.powtec.2017.12.069.
Full textDissertations / Theses on the topic "Eulerian-granular model"
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Tebowei, Roland. "Computational fluid dynamics (CFD) modelling of critical velocity for sand transport flow regimes in multiphase pipe bends." Thesis, Robert Gordon University, 2016. http://hdl.handle.net/10059/2118.
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The production and transportation of hydrocarbon fluids in multiphase pipelines could be severely hindered by particulate solids deposit such as produced sand particles which accompany hydrocarbon production. Knowledge of the flow characteristics of solid particles in fluids transported in pipelines is important in order to accurately predict solid particles deposition in pipelines. This research thesis presents the development of a three-dimensional (3D) Computational Fluids Dynamics (CFD) modelling technique for the prediction of liquid-solids multiphase flow in pipes, with special emphasis on the flow in V-inclined pipe bends. The Euler-Euler (two-fluid) multiphase modelling methodology has been adopted and the multiphase model equations and closure models describing the liquid-solids flow have been implemented and calculated using the finite volume method in a CFD code software. The liquid phase turbulence has been modelled using a two-equation k−ε turbulence model which contains additional terms to account for the effects of the solid-particles phase on the multiphase turbulence structure. The developed CFD numerical framework has been verified for the relevant forces and all the possible interaction mechanisms of the liquid-solids multiphase flow by investigating four different numerical frameworks, in order to determine the optimum numerical framework that captures the underlying physics and covers the interaction mechanisms that lead to sand deposition and the range of sand transport flow regimes in pipes. The flow of liquid-sand in pipe has been studied extensively and the numerical results of sand concentration distribution across pipe and other flow properties are in good agreement with published experimental data on validation. The numerical framework has been employed to investigate the multiphase flow in V-inclined pipe bends of ±4o−6o, seemingly small inclined bend angles. The predicted results which include the sand segregation, deposition velocity and flow turbulence modulation in the pipe bend show that the seemingly small pipe bends have significant effect on the flow differently from that of horizontal pipes. The pipe bend causes abrupt local change in the multiphase flow characteristic and formation of stationary sand deposit in the pipe at a relatively high flow velocity. The threshold velocity to keep sand entrained in liquid in pipe bends is significantly higher than that required for flow horizontal pipes. A critical implication of this is that the correlations for predicting sand deposition in pipelines must account for the effect of pipe bend on flow characteristics in order to provide accurate predictions of the critical sand transport velocity (MTV) in subsea petroleum flowlines, which V-inclined pipe bends are inevitable due to seabed topology.
Conference papers on the topic "Eulerian-granular model"
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Das, Kaushik, Debashis Basu, Kevin Smart, and Goodluck Ofoegbu. "Numerical Modeling and Parametric Assessment of Proppant Flow in Fractured Reservoirs." In ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-50051.
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Numerical simulation of proppant flow through a single idealized rectangular fracture in a reservoir has been conducted to understand the effect of various physical and operational parameters on proppant placement within a fracture. A three-dimensional Computational Fluid Dynamics model with a Eulerian-Granular (also referred to as Eulerian-Granular or Two-Fluid) model for solid particle transport simulations has been used to study the movement of proppant particles through this idealized single fracture. In the Eulerian-Granular method, the fluid-particle mixture is represented by two-phase interpenetrating continua with the particulate matter treated as a separate continuous phase. This Eulerian-Granular method depends on constitutive relationships to model additional terms for the solid phase. Parametric assessment has been carried out to analyze the influence of proppant size on the proppant settling behavior. In addition, the effects of fracture width and the effect of fluid viscosity have been studied. The simulations resolved the complex particle-particle as well as fluid-particle interactions. Computed results indicate that the proppant settling and fracture filling patterns depend on injected proppant size, with use of larger proppants, resulting in a relatively lower filling fraction. Results also show that lowering the fracturing fluid viscosity helps to disperse proppant particles more uniformly within the fracture. Narrower fractures have more pronounced wall effects that impede proppant movement, resulting in poorly filled fracture volume.
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Shi, Shaoping, Christopher Guenther, and Stefano Orsino. "Numerical Study of Coal Gasification Using Eulerian-Eulerian Multiphase Model." In ASME 2007 Power Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/power2007-22144.
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Gasification converts the carbon-containing material into a synthesis gas (syngas) which can be used as a fuel to generate electricity or used as a basic chemical building block for a large number of uses in the petrochemical and refining industries. Based on the mode of conveyance of the fuel and the gasifying medium, gasification can be classified into fixed or moving bed, fluidized bed, and entrained flow reactors. Entrained flow gasifiers normally feature dilute flow with small particle size and can be successfully modeled with the Discrete Phase Method (DPM). For the other types, the Eulerian-Eulerian (E-E) or the so called two-fluid multiphase model is a more appropriate approach. The E-E model treats the solid phase as a distinct interpenetrating granular “fluid” and it is the most general-purposed multi-fluid model. This approach provides transient, three-dimensional, detailed information inside the reactor which would otherwise be unobtainable through experiments due to the large scale, high pressure and/or temperature. In this paper, a transient, three-dimensional model of the Power Systems Development Facility (PSDF) transport gasifier will be presented to illustrate how Computational Fluid Dynamics (CFD) can be used for large-scale complicated geometry with detailed physics and chemistry. In the model, eleven species are included in the gas phase while four pseudo-species are assumed in the solid phase. A total of sixteen reactions, both homogeneous (involving only gas phase species) and heterogeneous (involving species in both gas and solid phases), are used to model the coal gasification chemistry. Computational results have been validated against PSDF experimental data from lignite to bituminous coals under both air and oxygen blown conditions. The PSDF gasifier geometry was meshed with about 70,000, hexahedra-dominated cells. A total of six cases with different coal, feed gas, and/or operation conditions have been performed. The predicted and measured temperature profiles along the gasifier and gas compositions at the outlet agreed fairly well.
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Choi, Moonho, Sungwon Lee, and Jin-Ki Ham. "Study on the Configuration Effect of a Vortex Finder for a Gas-Solid Cyclone Separator Using Eulerian-Eulerian Approach." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-63408.
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Granular model, a part of Eulerian-Eulerian approach is implemented to improve a gas-solid cyclone separator’s performances which are largely determined by dimensions of a vortex finder. Design-Of-Experiments method analyzes the performances such as pressure loss, separation efficiency, and erosion rate of each variation model due to the change of design parameters of the vortex finder. Separation efficiencies due to the motion of solid particles are predicted according to the classical efficiency model by using the method of least square. The numerical results are validated by comparing with previously reported experimental data. The standard Stairmand design cyclone is improved judging from the reduced pressure loss by 43%, the reduced cut size by 63% and the reduced erosion rate by 2% by changing the position and the diameter of the vortex finder.
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Ryan, Emily M., Wei Xu, David DeCroix, Kringan Saha, E. David Huckaby, Sebastian Dartevelle, and Xin Sun. "Multi-Phase CFD Modeling of a Solid Sorbent Carbon Capture System." In ASME 2012 Fluids Engineering Division Summer Meeting collocated with the ASME 2012 Heat Transfer Summer Conference and the ASME 2012 10th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/fedsm2012-72298.
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Post-combustion solid sorbent carbon capture systems are being studied via computational modeling as part of the U.S. Department of Energy’s Carbon Capture Simulation Initiative (CCSI). The work focuses on computational modeling of device-scale multi-phase computational fluid dynamics (CFD) simulations for given carbon capture reactor configurations to predict flow properties, outlet compositions, temperature and pressure. The detailed outputs of the device-scale models provide valuable insight into the operation of new carbon capture devices and will help in the design and optimization of carbon capture systems. As a first step in this project we have focused on modeling a 1 kWe solid sorbent carbon capture system using the commercial CFD software ANSYS FLUENT®. Using the multi-phase models available in ANSYS FLUENT®, we are investigating the use of Eulerian-Eulerian and Eulerian-Lagrangian methods for modeling a fluidized bed carbon capture design. The applicability of the dense discrete phase method (DDPM) is being considered along with the more traditional Eulerian-Eulerian multi-phase model. In this paper we will discuss the operation of the 1 kWe solid sorbent system and the setup of the DDPM and Eulerian-Eulerian models used to simulate the system. The results of the hydrodynamics in the system will be discussed and the predictions of the DDPM and Eulerian-Eulerian simulations will be compared. A discussion of the sensitivity of the model to boundary and initial conditions, computational meshing, granular pressure, and drag sub-models will also be presented.
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Cristea, Eugen-Dan, and Pierangelo Conti. "Hybrid Eulerian Multiphase-Dense Discrete Phase Model Approach for Numerical Simulation of Dense Particle-Laden Turbulent Flows Within Vertical Multi-Stage Cyclone Heat Exchanger." In ASME 2018 5th Joint US-European Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/fedsm2018-83058.
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This article describes a CFD engineering application developed to investigate numerically the multiphase, non-isothermal, turbulent flow physics within the suspension preheater of a dry-process rotary cement kiln. The multi–stage cyclone preheater is a counter-current heat exchanger. We used the CFD flow solver ANSYS-Fluent R18.1. to accomplish this task. The hybrid Eulerian multiphase-dense discrete phase model is a coupled Eulerian-Lagrangian technique. The primary carrier-phase is treated as a continuum by solving the Navier-Stokes equations, while the secondary discrete dispersed-phase is solved by tracking the particle parcels through the calculated flow field. The multiphase turbulence of the carrier-phase is modeled using the Reynolds stress transport model. The dispersed-phase interactions are modeled through the specific collisions models provided by the kinetic theory of granular flow and/or discrete element method. The Eulerian multiphase-DDPM method provided a quiet stable solution for a medium/high mass loading (solid to gas mass ratio 0.89:1). The four-stage cyclone suspension preheater is analyzed for its operating performance i.e. overall pressure drop and global collection efficiency of cyclone stages, calcination degree at bottom cyclone stage, flue gas temperature at 1st. cyclone stage and availability to get more insight of very complex multi-phase flow patterns within this equipment. The set of industrial measurements, collected during a heat and mass balance of a dry process rotary cement kiln, were used to verify and to validate part of the simulation results.
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Ling, J., C. X. Lin, and M. A. Ebadian. "Numerical Investigations of Double-Species Slurry Flow in a Straight Pipe Entrance." In ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-32057.
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Because of the complexity of multiphase slurry flow, most experiments and simulations described in the open literature are focused on single-species solid-liquid flow. In this paper, a Eulerian granular multiphase (EGM) model is introduced to make the numerical investigations in the entrance region of a straight pipe for a double-species slurry flow. In order for the study to obtain the numerical solution in fully developed turbulent flow, the k–ε turbulent model was used with the Eulerian granular multiphase model. An O-type structured grid was chosen to discretize the entire computation domain, and a control volume finite difference method (CVFDM) was applied in the governing equations. Some simulation results are compared with the authors’ experimental data to validate the numerical investigation. These numerical results for the pressure gradients are found to be in good agreement with the experimental data. It is very difficult to obtain some important flow characteristics in the double-species slurry flow by experiments; therefore, the volume fractions (or concentrations) of solids, the average velocity distributions, and the turbulent kinetic energy and dissipation rates of water in the pipe entrance will be displayed and analyzed in the numerical investigations, which have seldom been reported in the open literature.
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Kumar, Apurv, Jin-Soo Kim, and Wojciech Lipiński. "Radiation Characteristics of a Particle Curtain in a Free-Falling Particle Solar Receiver." In ASME 2017 Heat Transfer Summer Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/ht2017-5117.
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Radiation absorption by a particle curtain formed in a solar free falling particle receiver is investigated using a Eulerian-Eulerian granular two-phase model to solve the two-dimensional mass and momentum equations (CFD). The radiative transfer equation is subsequently solved by the Monte-Carlo (MC) ray-tracing technique using the CFD results to quantify the radiation intensity through the particle curtain. The CFD and MC results provide reliable opacity predictions and are validated with the experimental results available in literature. The particle curtain was found to absorb the solar radiation efficiently for smaller particles at high flowrates due to higher particle volume fraction and increased radiation extinction. However, at low mass-flowrates the absorption efficiency decreases for small and large particles.
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Mazumder, A. K. M. Monayem, Ting Wang, and Jobaidur R. Khan. "Design and Simulation of a Hybrid Entrained-Flow and Fluidized Bed Mild Gasifier: Part 2—Case Study and Analysis." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-64485.
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To help design a mild-gasifier, a reactive multiphase flow computational model has been developed in Part 1 using Eulerian-Eulerian method to investigate the thermal-flow and gasification process inside a conceptual, hybrid entrained-flow and fluidized-bed mild-gasifier. In Part 2, the results of the verifications and the progressive development from simple conditions without particles and reactions to complicated conditions with full reactive multiphase flow are presented. Development of the model starts from simulating single-phase turbulent flow and heat transfer in order to understand the thermal-flow behavior, followed by introducing seven global, homogeneous gasification reactions progressively added one equation at a time. Finally, the particles are introduced, and heterogeneous reactions are added in a granular flow field. The mass-weighted, adiabatic flame temperature is validated through theoretical calculation and the minimum fluidization velocity is found to be close to Ergun’s correlation. Furthermore, the predicted exit species composition is consistent with the equilibrium values.
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Brundage, Aaron L. "Modeling Compressive Reaction in Shock-Driven Secondary Granular Explosives." In ASME/JSME 2011 8th Thermal Engineering Joint Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/ajtec2011-44130.
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Hexanitrostilbene (HNS) is a secondary, granular explosive with a wide usage in commercial and governmental sectors. For example, HNS is used in the aerospace industry as boosters in rockets, in the oil and gas industry in linear shaped charge designs in wellbore perforating guns, and in a number of applications in the US Department of Energy (DOE) and Department of Defense (DoD). In many of these applications, neat granules of HNS are pressed without binder and device performance is achieved with shock initiation of the powdered bed. Previous studies have demonstrated that powdered explosives do not transmit sharp shocks, but produce dispersive compaction waves. These compaction waves can induce combustion in the material, leading to a phenomenon termed Deflagration-to-Detonation Transition (DDT). The Baer-Nunziato (B-N) multiphase model was developed to predict compressive reaction in granular energetic materials due to shock and non-shock inputs using non-equilibrium multiphase mixture theory. The B-N model was fit to historical data of HNS, and this model was used to predict recent impact experiments where samples pressed to approximately 60% of theoretical maximum density (TMD) were shock loaded by high-velocity flyers [1]. Shock wave computations were performed using CTH, an Eulerian, multimaterial, multidimensional, finite-volume shock physics code developed at Sandia National Laboratories [2]. Predicted interface velocities using the B-N model were shown to be in good agreement with the measurements. Furthermore, an uncertainty quantification study was performed and the computational results are presented with best estimates of uncertainty.
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Mendygarin, Yertay, Luis R. Rojas-Solórzano, Nurassyl Kussaiyn, Rakhim Supiyev, and Mansur Zhussupbekov. "Eulerian-Eulerian Multiphase Modeling of Blood Cells Segregation in Flow Through Microtubes." In ASME 2017 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/imece2017-70850.
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Cardiovascular Diseases, the common name for various Heart Diseases, are responsible for nearly 17.3 million deaths annually and remain the leading global cause of death in the world. It is estimated that this number will grow to more than 23.6 million by 2030, with almost 80% of all cases taking place in low and middle income countries. Surgical treatment of these diseases involves the use of blood-wetted devices, whose relatively recent development has given rise to numerous possibilities for design improvements. However, blood can be damaged when flowing through these devices due to the lack of biocompatibility of surrounding walls, thermal and osmotic effects and most prominently, due to the excessive exposure of blood cells to shear stress for prolonged periods of time. This extended exposure may lead to a rupture of membrane of red blood cells, resulting in a release of hemoglobin into the blood plasma, in a process called hemolysis. Moreover, exposure of platelets to high shear stresses can increase the likelihood of thrombosis. Therefore, regions of high shear stress and residence time of blood cells must be considered thoroughly during the design of blood-contacting devices. Though laboratory tests are vital for design improvements, in-vitro experiments have proven to be costly, time-intensive and ethically controversial. On the other hand, simulating blood behavior using Computational Fluid Dynamics (CFD) is considered to be an inexpensive and promising tool to help predicting blood damage in complex flows. Nevertheless, current state-of-the-art CFD models of blood flow to predict hemolysis are still far from being fully reliable and accurate for design purposes. Previous work have demonstrated that prediction of hemolysis can be dramatically improved when using a multiphase (i.e., phases are plasma, red blood cells and platelets) model of the blood instead of assuming the blood as a homogeneous mixture. Nonetheless, the accurate determination of how the cells segregate becomes the critical issue in reaching a truthful prediction of blood damage. Therefore, the attempt of this study is to develop and validate a numerical model based on Granular Kinetic Theory (GKT) for solid phases (i.e., cells treated as particles) that provides an improved prediction of blood cells segregation within the flow in a microtube. Simulations were based on finite volume method using Eulerian-Eulerian modeling for treatment of three-phase (liquid-red blood cells and platelets) flow including the GKT to deal with viscous properties of the solid phases. GKT proved to be a good model to predict particle concentration and pressure drop by taking into account the contribution of collisional, kinetic and frictional effects in the stress tensor of the segregated solid phases. Preliminary results show that the improved segregated model leads to a better prediction of spatial distribution of blood cells. Simulations were performed using ANSYS FLUENT platform.