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Numerical simulation of the head-on collision of two drops in a vertical channel

  • Maryam Hassanzadeh
  • Afshin Ahmadi NadooshanEmail author
  • Morteza Bayareh
Technical Paper
  • 21 Downloads

Abstract

The head-on collision between two oil drops in a vertical channel is investigated numerically by using a volume-of-fluid method. Three-dimensional simulations are examined for laminar, fully developed, unsteady, and incompressible fluid flow. The effects of the Weber and Reynolds numbers and the density ratio on the collision dynamics are investigated before and after the drop coalescence. The results show that the deformation of drops increases and gap thickness decreases as the Weber and Reynolds numbers increase. The drops collide with each other faster for higher density ratios. It is found that the drops elongation has a sinusoidal behavior after collision due to the tendency of the drops to gain a spherical shape. Also, the results demonstrate that the elongation increases with increasing of the Weber and Reynolds numbers and decreasing of the density ratio.

Keywords

Drop collision Two-phase flow VOF method Reynolds number Weber number Eotvos number 

List of symbols

b

The minor semi-axes of the drop (m)

D

Drop diameter (m)

e*

The drop elongation (m)

Eo

Eotvos number

F

Force (N)

g

Gravity acceleration

H

Channel height (m)

k

Curvature

l

The major semi-axes of the drop (m)

L

Channel length (m)

n

Normal vector (m)

Oh

Ohnesorge number

p

Pressure (Pa)

Re

Reynolds number

t

Time (s)

t*

Dimensionless time

u

Velocity (m/s)

We

Weber number

x

Position (m)

Greek letters

η

Density ratio

λ

Viscosity ratio

μ

Dynamic viscosity (N. s/m2)

ν

Kinematic viscosity (m2/s)

ρ

Density (kg/m3)

σ

Surface tension (N/s)

Subscripts

1, 2

Number of drop

d

Drop

f

Fluid

rel

Relative

st

Surface tension

Notes

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Copyright information

© The Brazilian Society of Mechanical Sciences and Engineering 2019

Authors and Affiliations

  1. 1.Department of Mechanical EngineeringShahrekord UniversityShahrekordIran

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