Direct numerical simulation of large bubbles in a free shear layer

The full Navier-Stokes equations were employed with a single-fluid model and a front tracking scheme to study large cylindrical, spherical, and ellipsoidal bubbles in a free shear layer. This approach allows direct simulation of the multiphase flow by wholly incorporating the bubble flow field in conjunction with the large scale vortical structures of the liquid. The role of large bubbles in modifying finite Reynolds number shear flow structures was investigated, specifically for bubbles whose diameter approaches the scale of the largest liquid eddies. Both two- and three-dimensional results indicate that duration of eddy crossing is the main mechanism for flow modulation, which is typically characterized by decreased vortex coherency and size, modified fluctuation statistics, and significant variations in pairing/merging phenomena. The comparison of fluctuating statistics and flow field visualization also allowed qualitative discrimination between the modulation of the non-linear eddy dynamics and fluctuations due simply to the random bubble induced perturbations. Increasing bubble deformation only has a minor effect on liquid flow modulation.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Aerospace Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Taeibi-Rahni, Mohammad

Contributors dc:contributor

• Loth, Eric

• Engineering, Aerospace
• Engineering, Chemical
• Engineering, Mechanical

Statement dc:rights

• Copyright 1995 Taeibi-Rahni, Mohammad

Language dc:language

eng

Identifier

AAI9543742
(UMI)AAI9543742

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/19782