0
Multiphase Flows

A Numerical Investigation on Dynamics and Breakup of Liquid Sheet

[+] Author and Article Information
Mohammad Ali1

 Department of Mechanical Engineering, BUET, Dhaka-1000, Bangladeshmali_buet@yahoo.com

Akira Umemura

 Department of Aerospace Engineering, Nagoya University, 464-8603 Nagoya, Japan

M. Quamrul Islam

 Department of Mechanical Engineering, BUET, Dhaka-1000, Bangladesh

1

Corresponding author.

J. Fluids Eng 134(10), 101303 (Sep 28, 2012) (9 pages) doi:10.1115/1.4007500 History: Received April 24, 2012; Revised August 18, 2012; Published September 24, 2012; Online September 28, 2012

The details on dynamics and breakup processes of liquid sheets are numerically investigated by considering two liquid sheet arrangements: the contraction of liquid sheet in a still quiescent gas medium, and a moving liquid sheet in a gas medium of much higher velocity compared with the liquid sheet. The first part of the study reveals that the surface tension forms the capillary wave on the liquid sheet surface. By extensive calculation, it is conformed that only surface tension force cannot disintegrate the liquid sheet. The dragging of liquid by co-flowing gas is very important for the occurrence of sheet breakup. To prove this concept, the second part of the investigation is performed, which reveals the details of breakup processes. Two effects are observed: the aerodynamic effect and the surface tension effect. The main function of the aerodynamic effect is to stretch the liquid sheet by drag force and create the steps on the sheet surface which is then followed by a pair of vortices and stagnation point prior to the end of every step. When the thickness of the sheet becomes thin enough, the dragging of liquid by the gas flow at the upstream of the neck part of the bulbous tip causes formation of a pair of vortices and stagnation point on the thin portion of the liquid sheet restricts the liquid flow and eventually the breakup occurs.

FIGURES IN THIS ARTICLE
<>
Copyright © 2012 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 3

Comparison of swell and neck diameters with experiment; average diameter of unperturbed cylinder, D0  = 1.86 mm

Grahic Jump Location
Figure 4

Schematic of the calculation domain for contraction of liquid sheet; a = half-thickness of liquid sheet

Grahic Jump Location
Figure 5

Evolution of capillary waves during contraction of liquid sheet; dimensionless time, (a) t = 0.0, (b) t = 0.89, (c) t = 7.06, (d) t = 11.12, (e) t = 19.47, (f) t = 27.18, and (g) t = 36.15

Grahic Jump Location
Figure 6

Nondimensional position of capillary waves at time, t = 36.18

Grahic Jump Location
Figure 7

Dimensionless pressure distribution along the horizontal axis of the liquid sheet at time, t = 36.18

Grahic Jump Location
Figure 8

Dimensionless horizontal velocity distribution along the horizontal axis of the liquid sheet at time, t = 36.18

Grahic Jump Location
Figure 9

Schematic of moving liquid sheet profile with initial condition; a = half thickness of the unperturbed liquid sheet

Grahic Jump Location
Figure 10

(a) A part of velocity vector field and horizontal velocity along x-axis at t = 0.54 when Weg  = 25, (b) a part of velocity vector field and horizontal velocity along x-axis at t = 1.08 when Weg  = 25, (c) a part of velocity vector field and horizontal velocity along x-axis at t = 1.73 when Weg  = 25, (d) a part of velocity vector field and horizontal velocity along x-axis at t = 2.37 when Weg  = 25; (a)–(d) a part of velocity vector field and horizontal velocity along x-axis at different dimensionless time when Weg  = 25

Grahic Jump Location
Figure 11

Structure of steps tended to develop by aerodynamic effect

Grahic Jump Location
Figure 12

(a) Nondimensional horizontal velocity and pressure distributions along x-axis at time, t = 2.56, Weg  = 25. (b) Nondimensional horizontal velocity and pressure distributions along x-axis at time, t = 2.61, Weg  = 25. (a)–(b) Nondimensional horizontal velocity and pressure distributions along x-axis at different dimensionless time near breakup, Weg  = 25.

Grahic Jump Location
Figure 2

The photograph of jet in experiment of Goedde and Yuen [22]

Grahic Jump Location
Figure 1

Liquid planar surface, ABCD cuts the cubic cell into two parts

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In