Motion of a neutrally buoyant circular particle in a clockwise double-lid-driven square cavity

2020 ◽  
Vol 32 (11) ◽  
pp. 113304
Author(s):  
Junjie Hu
Keyword(s):  
Square Cavity ◽  
Circular Particle ◽  
Neutrally Buoyant

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.

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.

Direct simulation of initial value problems for the motion of solid bodies in a Newtonian fluid. Part 2. Couette and Poiseuille flows

1994 ◽  
Vol 277 ◽  
pp. 271-301 ◽  
Author(s):  
J. Feng ◽  
H. H. Hu ◽  
D. D. Joseph
Keyword(s):  
Poiseuille Flow ◽  
Driving Forces ◽  
Particle Surface ◽  
Particle Rotation ◽  
Element Simulation ◽  
Circular Particle ◽  
Dimensional Finite Element ◽  
Shear Slip ◽  
Neutrally Buoyant ◽  
Solid Bodies

This paper reports the results of a two-dimensional finite element simulation of the motion of a circular particle in a Couette and a Poiseuille flow. The size of the particle and the Reynolds number are large enough to include fully nonlinear inertial effects and wall effects. Both neutrally buoyant and non-neutrally buoyant particles are studied, and the results are compared with pertinent experimental data and perturbation theories. A neutrally buoyant particle is shown to migrate to the centreline in a Couette flow, and exhibits the Segré-Silberberg effect in a Poiseuille flow. Non-neutrally buoyant particles have more complicated patterns of migration, depending upon the density difference between the fluid and the particle. The driving forces of the migration have been identified as a wall repulsion due to lubrication, an inertial lift related to shear slip, a lift due to particle rotation and, in the case of Poiseuille flow, a lift caused by the velocity profile curvature. These forces are analysed by examining the distributions of pressure and shear stress on the particle. The stagnation pressure on the particle surface are particularly important in determining the direction of migration.

Numerical analysis and explore of asymmetrical fluid flow in a two-sided lid-driven cavity

2020 ◽  
Vol 14 (3) ◽  
pp. 7269-7281
Author(s):  
El Amin Azzouz ◽  
Samir Houat
Keyword(s):  
Velocity Ratio ◽  
Two Dimensional ◽  
Lower Side ◽  
Square Cavity ◽  
Driven Cavity ◽  
Parallel Motion ◽  
Bottom Cavity ◽  
Secondary Vortices ◽  
Volume Method ◽  
Fluid Characteristics

The two-dimensional asymmetrical flow in a two-sided lid-driven square cavity is numerically analyzed by the finite volume method (FVM). The top and bottom walls slide in parallel and antiparallel motions with various velocity ratio (UT/Ub=λ) where |λ|=2, 4, 8, and 10. In this study, the Reynolds number Re1 = 200, 400, 800 and 1000 is applied for the upper side and Re2 = 100 constant on the lower side. The numerical results are presented in terms of streamlines, vorticity contours and velocity profiles. These results reveal the effect of varying the velocity ratio and consequently the Reynolds ratio on the flow behaviour and fluid characteristics inside the cavity. Unlike conventional symmetrical driven flows, asymmetrical flow patterns and velocity distributions distinct the bulk of the cavity with the rising Reynolds ratio. For λ>2, in addition to the main vortex, the parallel motion of the walls induces two secondary vortices near the bottom cavity corners. however, the antiparallel motion generates two secondary vortices on the bottom right corner. The parallel flow proves affected considerably compared to the antiparallel flow.

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