Turbulent micro-structure in a bubbly channel flow

Akiko Fujiwara, Koichi Hishida

Research output: Contribution to journalArticle

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
Publication statusPublished - 2002 Apr

Fingerprint

Void fraction
channel flow
Channel flow
Flow structure
bubbles
microstructure
Microstructure
Bubbles (in fluids)
Turbulence
Surface active agents
Modulation
vorticity
particle image velocimetry
laser induced fluorescence
voids
Experiments
spacing
turbulence
surfactants
modulation

Keywords

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

ASJC Scopus subject areas

  • Mechanical Engineering

Cite this

Turbulent micro-structure in a bubbly channel flow. / Fujiwara, Akiko; Hishida, Koichi.

In: Nippon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B, Vol. 68, No. 668, 04.2002, p. 1143-1150.

Research output: Contribution to journalArticle

@article{4ed9b8d722ae440791f1e8706a387a28,
title = "Turbulent micro-structure in a bubbly channel flow",
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.",
keywords = "Bubble, Channel flow, Multi-phase flow, PIV/LIF/IST, Turbulent flow",
author = "Akiko Fujiwara and Koichi Hishida",
year = "2002",
month = "4",
language = "English",
volume = "68",
pages = "1143--1150",
journal = "Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B",
issn = "0387-5016",
publisher = "Japan Society of Mechanical Engineers",
number = "668",

}

TY - JOUR

T1 - Turbulent micro-structure in a bubbly channel flow

AU - Fujiwara, Akiko

AU - Hishida, Koichi

PY - 2002/4

Y1 - 2002/4

N2 - 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.

AB - 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.

KW - Bubble

KW - Channel flow

KW - Multi-phase flow

KW - PIV/LIF/IST

KW - Turbulent flow

UR - http://www.scopus.com/inward/record.url?scp=0036556006&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0036556006&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0036556006

VL - 68

SP - 1143

EP - 1150

JO - Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B

JF - Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B

SN - 0387-5016

IS - 668

ER -