Turbulent micro-structure in a bubbly channel flow

Akiko Fujiwara, Koichi Hishida

Research output: Contribution to journalArticlepeer-review

Abstract

The objective of the present study is to elucidate the mechanism of interaction between global and local structure of turbulence, especially the influenced of inter-bubble spacing on the microscopic flow structure in bubbly flow. We explored the flow structure in the vicinity of the bubble in conjunction with bubble deformation by PIV/LIF and a shadow image technique respectively. The experiment consisted of a fully developed vertical upward channel flow with 0.5% and 1.0% void fraction. We used a small quantity of 3-Pentanol as surfactant to control the bubble diameter and number density of bubble. Our main conclusion is that not only the void fraction but also the distribution of the bubble diameter serves as characteristic spatial parameters of the turbulent structure of bubbly flow. Enstrophy contours characterizing turbulent modulation were derived from velocity data measured by PIV/LIF. The high intensity of enstrophy was distributed around the large bubble and in the narrow inter-bubble spacing. The spatial scale of enstrophy was almost the same as the vorticies induced by these large bubbles.

Original languageEnglish
Pages (from-to)1143-1150
Number of pages8
JournalNippon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B
Volume68
Issue number668
DOIs
Publication statusPublished - 2002 Apr

Keywords

  • Bubble
  • Channel flow
  • Multi-phase flow
  • PIV/LIF/IST
  • Turbulent flow

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanical Engineering

Fingerprint

Dive into the research topics of 'Turbulent micro-structure in a bubbly channel flow'. Together they form a unique fingerprint.

Cite this