Dynamics of a neutrally buoyant circular particle moving in a parallel double-lid-driven square cavity

2021 ◽  
pp. 2150067
Author(s):  
Junjie Hu
Keyword(s):  
Particle Size ◽  
Lattice Boltzmann ◽  
Initial Position ◽  
Square Cavity ◽  
Circular Particle ◽  
Left Corner ◽  
Bottom Left ◽  
Boltzmann Method ◽  
And Control ◽  
Neutrally Buoyant

The motion of a neutrally buoyant circular particle in a parallel double-lid-driven square cavity is studied with the lattice Boltzmann method. To understand, predict and control the motion of the circular particle, the effects of the initial position and particle size are studied. If the circular particle is placed at the centerline of the square cavity, at the steady state, it is confined at the bottom left corner, otherwise, the circular particle is stabilized at the 8-like trajectory, which is created by both the inertia of the circular particle and the confinement of the boundaries of the square cavity. The effect of the particle size on the motion of the circular particle is obvious, with the increase of the particle size, the confinement of the boundaries of the square cavity becomes stronger, and the 8-like trajectory shrinks toward the center. Furthermore, if the particle size is large enough, the centrifugal motion of the circular particle becomes weaker, and the circular particle cannot cross the centerline of the square cavity.

scholarly journals Two-Dimensional Numerical Study on the Migration of Particle in a Serpentine Channel

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Yi Liu ◽  
Qucheng Li ◽  
Deming Nie
Keyword(s):  
Lattice Boltzmann ◽  
Particle Density ◽  
Numerical Study ◽  
Density Ratio ◽  
Initial Position ◽  
Momentum Exchange ◽  
Initial Particle ◽  
Serpentine Channel ◽  
Circular Particle ◽  
Boltzmann Method

In this work, the momentum exchange scheme-based lattice Boltzmann method is adopted to numerically study the migration of a circular particle in a serpentine channel for the range of 20 ≤ Re ≤ 120. The effects of the Reynolds number, particle density, and the initial particle position are taken into account. Numerical results include the streamlines, particle trajectories, and final equilibrium positions. Close attention is also paid to the time it takes for the particle to travel in the channel. It has been found that the particle is likely to migrate to a similar equilibrium position irrespective of its initial position when Re is large. Furthermore, there exists a critical solid-to-fluid density ratio for which the particle travels fastest in the channel.

Dynamics of a pair of neutrally buoyant circular particles with different sizes in a lid-driven square cavity

2021 ◽  
pp. 2250005
Author(s):  
Junjie Hu ◽  
Hui Pan ◽  
Fangqing Zhang ◽  
Huili Wang ◽  
Gaojie Liu ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Lattice Boltzmann ◽  
Food Processing ◽  
Cell Separation ◽  
Solid Particles ◽  
Square Cavity ◽  
Velocity Difference ◽  
Processing Water ◽  
Boltzmann Method ◽  
Neutrally Buoyant

The solid particles with different sizes exist widely, like cell separation, food processing, water treatment, thus, investigating the motion of the solid particles with different sizes is important. This study investigates the motion of a pair of neutrally buoyant circular particles with different sizes in a lid-driven square cavity using the lattice Boltzmann method. The motion of the circular particles with different sizes and that of the circular particles with identical sizes are quite different. The steady trajectories of the circular particles with identical sizes are identical, which is not affected by the Reynolds number. Differently, the circular particles with different sizes orbit along different steady trajectories, namely, the steady trajectory of the small particle is closer to the walls of the square cavity, while that of the large particle shrinks toward the center of the square cavity, which may provide us a possible method to separate them. However, it is not always effective, if the Reynolds number is low, the velocity difference between the circular particles with different sizes is small, which may fail to separate them completely.

scholarly journals Neutrally Buoyant Particle Migration in Poiseuille Flow Driven by Pulsatile Velocity

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1075
Author(s):  
Lizhong Huang ◽  
Jiayou Du ◽  
Zefei Zhu
Keyword(s):  
Lattice Boltzmann ◽  
Essential Role ◽  
Damping Ratio ◽  
Particle Migration ◽  
Immersed Boundary ◽  
Time Period ◽  
Circular Particle ◽  
Boltzmann Method ◽  
Neutrally Buoyant ◽  
Underdamped Oscillation

A neutrally buoyant circular particle migration in two-dimensional (2D) Poiseuille channel flow driven by pulsatile velocity is numerical studied by using immersed boundary-lattice Boltzmann method (IB-LBM). The effects of Reynolds number (25≤Re≤200) and blockage ratio (0.15≤k≤0.40) on particle migration driven by pulsatile and non-pulsatile velocity are all numerically investigated for comparison. The results show that, different from non-pulsatile cases, the particle will migrate back to channel centerline with underdamped oscillation during the time period with zero-velocity in pulsatile cases. The maximum lateral travel distance of the particle in one cycle of periodic motion will increase with increasing Re, while k has little impact. The quasi frequency of such oscillation has almost no business with Re and k. Moreover, Re plays an essential role in the damping ratio. Pulsatile flow field is ubiquitous in aorta and other arteries. This article is conducive to understanding nanoparticle migration in those arteries.

scholarly journals Waterfall Algorithm as a tool of investigation the geometrical features of granular porous media

2021 ◽  
Author(s):  
Wojciech Sobieski
Keyword(s):  
Particle Size ◽  
Porous Media ◽  
Lattice Boltzmann ◽  
Granular Media ◽  
Density Ratio ◽  
Geometrical Features ◽  
Granular Porous Media ◽  
Collision Density ◽  
Boltzmann Method ◽  
The Impact

AbstractThe paper describes the so-called Waterfall Algorithm, which may be used to calculate a set of parameters characterising the spatial structure of granular porous media, such as shift ratio, collision density ratio, consolidation ratio, path length and minimum tortuosity. The study is performed for 1800 different two-dimensional random pore structures. In each geometry, 100 individual paths are calculated. The impact of porosity and the particle size on the above-mentioned parameters is investigated. It was stated in the paper, that the minimum tortuosity calculated by the Waterfall Algorithm cannot be used directly as a representative tortuosity of pore channels in the Kozeny or the Carman meaning. However, it may be used indirect by making the assumption that a unambiguous relationship between the representative tortuosity and the minimum tortuosity exists. It was also stated, that the new parameters defined in the present study are sensitive on the porosity and the particle size and may be therefore applied as indicators of the geometry structure of granular media. The Waterfall Algorithm is compared with other methods of determining the tortuosity: A-Star Algorithm, Path Searching Algorithm, Random Walk technique, Path Tracking Method and the methodology of calculating the hydraulic tortuosity based on the Lattice Boltzmann Method. A very short calculation time is the main advantage of the Waterfall Algorithm, what meant, that it may be applied in a very large granular porous media.

Aerodynamics Research of Thermal Fluid Circulation in a Heated Cavity

2014 ◽  
Vol 668-669 ◽  
pp. 326-330
Author(s):  
Guang Zhao
Keyword(s):  
Lattice Boltzmann ◽  
Area Ratio ◽  
Circulation Rate ◽  
Fluid Circulation ◽  
Square Cavity ◽  
Heating Source ◽  
Mass And Heat Transfer ◽  
Boltzmann Method ◽  
Thermal Lattice Boltzmann ◽  
Rayleigh Numbers

In this paper, numerical simulation of natural convection in a closure square cavity with heating source on the basement is carried out using thermal lattice Boltzmann method. The purpose of this work is to analysis the physics of mass and heat transfer in such a condition. For different Rayleigh numbers, the relative heating area ratio is changed in the range of 0.1-1.0, correspondingly. It is found that the flow pattern is symmetrical for increases from 103to 106, and the boundary layers at low temperature become thinner, also the circulation rate is higher. For a special Rayleigh number, is as a monotone increment function of relative heating area ratio, and the value of which almost increases linearly when the area is below 0.8, and then reach to its maximum exponentially.

SIMULATION OF NATURAL CONVECTION IN A SQUARE CAVITY BY TAYLOR SERIES EXPANSION- AND LEAST SQUARES-BASED LATTICE BOLTZMANN METHOD

2002 ◽  
Vol 13 (10) ◽  
pp. 1399-1414 ◽  
Author(s):  
C. SHU ◽  
Y. PENG ◽  
Y. T. CHEW
Keyword(s):  
Natural Convection ◽  
Least Squares ◽  
Lattice Boltzmann Method ◽  
Series Expansion ◽  
Taylor Series ◽  
Lattice Boltzmann ◽  
Taylor Series Expansion ◽  
Uniform Grid ◽  
Square Cavity ◽  
Boltzmann Method

The Taylor series expansion- and least squares-based lattice Boltzmann method (TLLBM) was used in this paper to extend the current thermal model to an arbitrary geometry so that it can be used to solve practical thermo-hydrodynamics in the incompressible limit. The new explicit method is based on the standard lattice Boltzmann method (LBM), Taylor series expansion and the least squares approach. The final formulation is an algebraic form and essentially has no limitation on the mesh structure and lattice model. Numerical simulations of natural convection in a square cavity on both uniform and nonuniform grids have been carried out. Favorable results were obtained and compared well with the benchmark data. It was found that, to get the same order of accuracy, the number of mesh points used on the nonuniform grid is much less than that used on the uniform grid.

Study of mixed convection in closed enclosure with a ceiling fan

2019 ◽  
Vol 86 (2) ◽  
pp. 20902 ◽  
Author(s):  
Lyes Nasseri ◽  
Omar Rahli ◽  
Djamel Eddine Ameziani ◽  
Rachid Bennacer
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Rayleigh Number ◽  
Lattice Boltzmann ◽  
Transfer Rate ◽  
Numerical Study ◽  
Square Cavity ◽  
Flow Intensity ◽  
Vertical Walls ◽  
Boltzmann Method

This paper presents a numerical study of heat transfer by convection in a square cavity. The vertical walls of the cavity are differentially heated and the horizontal ones are considered adiabatic. A fan is placed in the middle of the cavity and releases a jet down. Numerical simulation was performed using the lattice Boltzmann method to show the flow patterns and the heat flux depending on the Rayleigh number (thermal convection intensity) and the Reynolds number (fan-driven flow intensity). A parametric study was performed presenting the influence of Reynolds number (20 ≤ Re ≤ 500), Rayleigh number (10 ≤ Ra ≤ 106) and the fan position (0.2 ≤ HF ≤ 0.8). In forced convection mode, the flow structure has been mapped according to the position and the power of the fan. Three structures have emerged: two symmetrical cells, four symmetrical cells and asymmetrical structure. It has been observed that the heat transfer rate increases with the rise of Reynolds number and the reduction of the distance of the fan position from the ceiling. For the latter one, an unfavorable evolution of Nusselt number is observed for Ra > 104.

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