Numerical simulation of the behavior of insulating particles in a free fall tribo-electrostatic separator with four vertical cylindrical electrodes

Numerical experiments can be used to study heavy particle dispersion by tracking particles through a numerically generated instantaneous turbulent flow field. In this manner, data can be generated to supplement physical experiments. To perform the numerical experiments efficiently and accurately, the time step used when tracking the particles through the fluid must be chosen correctly. After finding a suitable time step for one particular simulation, the time step must be reduced as the total integration time increases and as the free-fall velocity of the particle increases. Based on the numerical calculations, we suggest that the nonlinear drag be included in a numerical simulation if the ratio of the particle’s Stokes free-fall velocity to the fluid rms velocity is greater than two.

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A comparative study on the behaviour of free-fall lifeboat launching from a skid and from a hook

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1243/0954406001523029 ◽

2000 ◽

Vol 214 (2) ◽

pp. 359-370 ◽

Cited By ~ 2

Author(s):

M Reaz H Khondoker ◽

M Arai

Keyword(s):

Numerical Simulation ◽

Dynamic Response ◽

Comparative Study ◽

Impact Force ◽

Free Fall ◽

Water Entry ◽

Hydrodynamic Forces ◽

Response Criteria ◽

Risk Of Injury ◽

Tremendous Impact

There are two commonly used launching methods of free-fall lifeboats: from a skid and from a hook. A free-fall lifeboat, whether it is released from a skid or from a hook, experiences tremendous impact when it enters the water. This impact force, together with other hydrostatic and hydrodynamic forces and moments, affects the motions and accelerations of the boat considerably. In this paper, a comparative study on the behaviours of the skid and hook launching of free-fall lifeboats has been presented. Numerical simulation for different launching methods has been used as a tool to obtain trajectories of the lifeboat for different launching conditions. Also polar diagrams of accelerations are drawn using the data computed for the same conditions. Dynamic response criteria have been used in order to evaluate the risk of injury to the occupants during water entry of the lifeboat.

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Portable Free-Fall Electrostatic Separator for Beneficiation of Charged Particulate Materials

Particulate Science And Technology ◽

10.1080/02726350802084200 ◽

2008 ◽

Vol 26 (4) ◽

pp. 349-360 ◽

Cited By ~ 6

Author(s):

D. Saini ◽

S. Trigwell ◽

P. K. Srirama ◽

R. A. Sims ◽

R. Sharma ◽

...

Keyword(s):

Free Fall ◽

Particulate Materials ◽

Electrostatic Separator

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On the numerical simulation of the unsteady free fall of a solid in a fluid: I. The Newtonian case

Computers & Fluids ◽

10.1016/j.compfluid.2007.01.010 ◽

2007 ◽

Vol 36 (9) ◽

pp. 1434-1445 ◽

Cited By ~ 15

Author(s):

S. Bönisch ◽

V. Heuveline

Keyword(s):

Numerical Simulation ◽

Free Fall ◽

Newtonian Case

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Numerical simulation of circular cylinders in free-fall

Journal of Fluids and Structures ◽

10.1016/j.jfluidstructs.2015.11.010 ◽

2016 ◽

Vol 61 ◽

pp. 154-167 ◽

Cited By ~ 9

Author(s):

Pedro Romero-Gomez ◽

Marshall C. Richmond

Keyword(s):

Numerical Simulation ◽

Free Fall ◽

Circular Cylinders

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A study on the hydrodynamic performance of manta ray biomimetic glider under unconstrained six-DOF motion

PLoS ONE ◽

10.1371/journal.pone.0241677 ◽

2020 ◽

Vol 15 (11) ◽

pp. e0241677

Author(s):

Wen-Hao Cai ◽

Jie-Min Zhan ◽

Ying-Ying Luo

Keyword(s):

Numerical Simulation ◽

Center Of Mass ◽

Free Fall ◽

Hydrodynamic Performance ◽

Dynamic Update ◽

Fall Experiment ◽

Six Dof ◽

The Stability ◽

Manta Ray ◽

Mesh Update

A manta ray biomimetic glider is designed and studied with both laboratory experiments and numerical simulations with a new dynamic update method called the motion-based zonal mesh update method (MBZMU method) to reveal its hydrodynamic performance. Regarding the experimental study, an ejection gliding experiment is conducted for qualitative verification, and a hydrostatic free-fall experiment is conducted to quantitatively verify the reliability of the corresponding numerical simulation. Regarding the numerical simulation, to reduce the trend of nose-up movement and to obtain a long lasting and stable gliding motion, a series of cases with the center of mass offset forward by different distances and different initial angles of attack have been calculated. The results show that the glider will show the optimal gliding performance when the center of mass is 20mm in front of the center of geometry and the initial attack angle range lies between A0 = -5° to A0 = -2.5° at the same time. The optimal gliding distance can reach six times its body length under these circumstances. Furthermore, the stability of the glider is explained from the perspective of Blended-Wing-Body (BWB) configuration.

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