Numerical simulation of flow behavior of agglomerates in gas–cohesive particles fluidized beds using agglomerates-based approach

For plastic processing extruders with grooved feed sections, the design of the feed section by means of analytical calculation models can be useful to reduce experimental costs. However, these models include assumptions and simplifications that can significantly decrease the prediction accuracy of the throughput due to complex flow behavior. In this paper, the accuracy of analytical modeling for calculating the throughput in a grooved barrel extruder is verified based on a statistical design of experiments. A special focus is placed on the assumptions made in the analytics of a backpressure-independent throughput, the assumption of a block flow and the differentiation of the solids conveying into different conveying cases. Simulative throughput tests with numerical simulation software using the discrete element method, as well as experimental throughput tests, serve as a benchmark. Overall, the analytical modeling already shows a very good calculation accuracy. Nevertheless, there are some outliers that lead to larger deviations in the throughput. The model predominantly overestimates the throughputs, whereby the origin of these deviations is often in the conveying angle calculation. Therefore, a regression-based correction factor for calculating the conveying angle is developed and implemented.

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Numerical simulation of flow behavior of particles in a gas-solid stirred fluidized bed

Powder Technology ◽

10.1016/j.powtec.2018.07.020 ◽

2018 ◽

Vol 338 ◽

pp. 119-128 ◽

Cited By ~ 4

Author(s):

Shuyan Wang ◽

Yujia Chen ◽

Yubin Jia ◽

Ruichao Tian ◽

Qiji Sun ◽

...

Keyword(s):

Numerical Simulation ◽

Fluidized Bed ◽

Flow Behavior

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Dynamic Flow Behavior Measurements in Gas-Solid Fluidized Beds Using Different Non-Intrusive Techniques and Polyethylene Powder

10.1063/1.2747508 ◽

2007 ◽

Author(s):

Bangyou Wu ◽

Guang Yu ◽

Celine Bellehumeur ◽

Apostolos Kantzas

Keyword(s):

Fluidized Beds ◽

Flow Behavior ◽

Dynamic Flow ◽

Polyethylene Powder

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SPH Simulation of Interior and Exterior Flow Field Characteristics of Porous Media

Water ◽

10.3390/w12030918 ◽

2020 ◽

Vol 12 (3) ◽

pp. 918 ◽

Cited By ~ 3

Author(s):

Shijie Wu ◽

Matteo Rubinato ◽

Qinqin Gui

Keyword(s):

Numerical Simulation ◽

Porous Media ◽

Flow Field ◽

Boundary Conditions ◽

Water Waves ◽

Flow Behavior ◽

Simulation Method ◽

Interface Problem ◽

Ocean Engineering ◽

Flow Field Characteristics

At the present time, one of the most relevant challenges in marine and ocean engineering and practice is the development of a mathematical modeling that can accurately replicate the interaction of water waves with porous coastal structures. Over the last 60 years, multiple techniques and solutions have been identified, from linearized solutions based on wave theories and constant friction coefficients to very sophisticated Eulerian or Lagrangian solvers of the Navier-Stokes (NS) equations. In order to explore the flow field interior and exterior of the porous media under different working conditions, the Smooth Particle Hydrodynamics (SPH) numerical simulation method was used to simulate the flow distribution inside and outside a porous media applied to interact with the wave propagation. The flow behavior is described avoiding Euler’s description of the interface problem between the Euler mesh and the material selected. Considering the velocity boundary conditions and the cyclical circulation boundary conditions at the junction of the porous media and the water flow, the SPH numerical simulation is used to analyze the flow field characteristics, as well as the longitudinal and vertical velocity distribution of the back vortex flow field and the law of eddy current motion. This study provides innovative insights on the mathematical modelling of the interaction between porous structures and flow propagation. Furthermore, there is a good agreement (within 10%) between the numerical results and the experimental ones collected for scenarios with porosity of 0.349 and 0.475, demonstrating that SPH can simulate the flow patterns of the porous media, the flow through the inner and outer areas of the porous media, and the flow field of the back vortex region. Results obtained and the new mathematical approach used can help to effectively simulate with high-precision the changes along the water depth, for a better design of marine and ocean engineering solutions adopted to protect coastal areas.

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