Observation of combustion mechanisms of acoustically levitated droplet clusters

Translated title of the contribution: Observation of combustion mechanisms of acoustically levitated droplet clusters

Seung Mo Kim, Fumiteru Akamatsu, Hiroyasu Saito, Chul Ju Ahn, Hiroyuki Torikai, Akio Kitajima, Masashi Katsuki

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

In order to elucidate the microscopic combustion behaviors of droplet clusters, we took advantage of droplet clusters suspended in the air almost at the same position using an ultrasonic levitator. We observed images of OH Laser Induced Predissociative Fluorescence (LIPF) and Mie-scattering of droplets simultaneously to examine relations between the combustion reaction zone and unburned droplet regions for confirming droplet group combustion mode of the clusters. In addition, we observed time-series images of Mie-scattering of burning droplets illuminated by a laser-sheet, and light emission in CH band at the same time. Simultaneously at a specific point in the imaged region, OH radical chemiluminescence was detected by specially designed light collection optics, Multi-color Integrated Receiving Optics (MICRO), and velocity and diameter of droplets were measured by Phase Doppler Analyzer (PDA) to obtain Characteristics of spray. We calculated the diameter of each droplet in a cluster based on the Mie-scattering theory, and derived droplet group combustion number of the droplet cluster in time-series. As a result, number density of droplets in the cluster decreased monotonically in case of the low number-density clusters. In contrast, number density of droplets in the cluster decreased first and kept constant, and then decreased again in case of the high number-density clusters. This is explained due to the fact that the droplet group combustion mode changed from the internal group combustion mode to the single droplet combustion mode.

Original languageJapanese
Pages (from-to)2552-2559
Number of pages8
JournalNihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B
Volume71
Issue number710
Publication statusPublished - 2005 Oct
Externally publishedYes

Fingerprint

Mie scattering
optics
Scattering
chemiluminescence
Time series
Optics
laser induced fluorescence
light emission
sprayers
analyzers
ultrasonics
Chemiluminescence
Lasers
Light emission
methylidyne
color
air
Ultrasonics
Fluorescence
lasers

Keywords

  • Combustion Mechanisms
  • Droplet Group Combustion
  • Spray Combustion

ASJC Scopus subject areas

  • Mechanical Engineering

Cite this

Observation of combustion mechanisms of acoustically levitated droplet clusters. / Kim, Seung Mo; Akamatsu, Fumiteru; Saito, Hiroyasu; Ahn, Chul Ju; Torikai, Hiroyuki; Kitajima, Akio; Katsuki, Masashi.

In: Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B, Vol. 71, No. 710, 10.2005, p. 2552-2559.

Research output: Contribution to journalArticle

Kim, Seung Mo ; Akamatsu, Fumiteru ; Saito, Hiroyasu ; Ahn, Chul Ju ; Torikai, Hiroyuki ; Kitajima, Akio ; Katsuki, Masashi. / Observation of combustion mechanisms of acoustically levitated droplet clusters. In: Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B. 2005 ; Vol. 71, No. 710. pp. 2552-2559.
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