Shear flow laminarization and acceleration by suspended heavy particles: A mathematical model and geophysical applications

In the present work, the solidification behaviour of a metal analogues transparent binary solution (8 wt% of NH4Cl in H2O) under shear flow is investigated numerically. The shear flow in the mush is developed due to flow over an inclined cooling plate. The dendrites formed during solidification are fragmented under the shear flow and transported into the bulk solution. The suspended dendrites form a slurry layer in the domain. Consequently, a suitable mathematical model is considered to study the transport phenomena. In the mathematical model, the free surface of the solution is represented by the volume-of-fluid (VOF) method. The solidification process is modelled by a set of volume-averaged-single-phase mass, momentum, energy and species conservation equations. A separate equation is considered for the solid velocity based on Stokes model. The governing equations are solved based on the pressure-based semi-implicit finite volume method according to the SIMPLER algorithm using TDMA solver along with the enthalpy update scheme. Finally, the simulation predicts temperature, velocity, solid fraction and the species distributions in the computational domain. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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Turbulence modification in a homogeneous turbulent shear flow laden with small heavy particles

International Journal of Heat and Fluid Flow ◽

10.1016/s0142-727x(02)00157-1 ◽

2002 ◽

Vol 23 (5) ◽

pp. 615-626 ◽

Cited By ~ 14

Author(s):

Mitsuru Tanaka ◽

Yasushi Maeda ◽

Yoshimichi Hagiwara

Keyword(s):

Shear Flow ◽

Turbulent Shear ◽

Turbulent Shear Flow ◽

Heavy Particles ◽

Turbulence Modification

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Behavior of heavy particles in an acoustically forced confined shear flow

AIAA Journal ◽

10.2514/3.13413 ◽

1996 ◽

Vol 34 (11) ◽

pp. 2429-2431 ◽

Cited By ~ 5

Author(s):

E. J. Chang ◽

K. Kailasanath

Keyword(s):

Shear Flow ◽

Heavy Particles

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Particle motions near the bottom in turbulent flow in an open channel. Part 2

Journal of Fluid Mechanics ◽

10.1017/s0022112081001092 ◽

1981 ◽

Vol 109 ◽

pp. 311-337 ◽

Cited By ~ 131

Author(s):

B. Mutlu Sumer ◽

Rolf Deigaard

Keyword(s):

Open Channel ◽

Three Dimensions ◽

Rough Boundary ◽

Heavy Particles ◽

Particle Properties ◽

Flow Reynolds Number ◽

Boundary Case ◽

Suspended Heavy Particles ◽

Available Information ◽

Bursting Process

This study continues the investigation of particle motions near the bottom in a turbulent open channel flow, reported by Sumer & Oguz (1978; hereafter referred to as part 1). Paths of suspended heavy particles were recorded in three dimensions and in time, employing a stereo-photogrammetric system coupled with a stroboscope. In the case of smooth bottom, the measured kinematical quantities concerning the particle motions were found to be in accord with the available information on the ‘bursting process’. Agreement between the particle motion and the bursting process provided further support for the mechanism of particle suspension near the bottom proposed in part 1. Similar experiments were carried out when the bottom was rough. Comparison between the smooth- and rough-bottom cases could be made on the same basis as the flow Reynolds number as well as the particle properties were kept almost unchanged in both the smooth and rough boundary experiments. The observations showed that particle motions close to the rough bottom are very similar in character to those in the smooth-bottom case. The findings of the present paper suggested that the suspension mechanism given for the smooth-boundary flow could be extended to the rough-boundary case.

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