Publication detail
Internal two-phase flow and spray characteristics of outside-in-liquid twin-fluid atomizers
HAMMAD, F. SUN, K. CHE, Z. JEDELSKÝ, J. TIANYOU, W.
English title
Internal two-phase flow and spray characteristics of outside-in-liquid twin-fluid atomizers
Type
journal article in Web of Science
Language
en
Original abstract
Despite its wide industrial applications, the internal-mixing twin-fluid atomization suffers a major problem of spray unsteadiness. This work links the flow characteristics inside a newly designed outside-in-liquid (OIL) atomizer with the spray stability and quality by flow visualization and digital image processing. The results show that the inhomogeneous bubbly and slug flow regimes cause an unwanted intermittent flow inside the exit orifice and an unstable coarse spray, while the stable-annular or the wavy-annular chamber flows provide a favorable continuous annular flow inside the exit orifice and a stable fine spray. By proposing a new parameter considering liquid/gas momentum ratio per liquid injection hole, a flow regime map is constructed, and the transition criterion between the favorable annular flow and the unfavorable intermittent flow regimes inside the exit orifice is obtained. A direct relation between the Sauter mean diameter of the spray droplets and the internal flow transition parameter is found. This study indicates that, under specific internal geometries, the optimized OIL atomizer can overcome the spray unsteadiness problem and hence is suitable for applications requiring high spray stability and quality.
English abstract
Despite its wide industrial applications, the internal-mixing twin-fluid atomization suffers a major problem of spray unsteadiness. This work links the flow characteristics inside a newly designed outside-in-liquid (OIL) atomizer with the spray stability and quality by flow visualization and digital image processing. The results show that the inhomogeneous bubbly and slug flow regimes cause an unwanted intermittent flow inside the exit orifice and an unstable coarse spray, while the stable-annular or the wavy-annular chamber flows provide a favorable continuous annular flow inside the exit orifice and a stable fine spray. By proposing a new parameter considering liquid/gas momentum ratio per liquid injection hole, a flow regime map is constructed, and the transition criterion between the favorable annular flow and the unfavorable intermittent flow regimes inside the exit orifice is obtained. A direct relation between the Sauter mean diameter of the spray droplets and the internal flow transition parameter is found. This study indicates that, under specific internal geometries, the optimized OIL atomizer can overcome the spray unsteadiness problem and hence is suitable for applications requiring high spray stability and quality.
Keywords in English
Twin-fluid atomization, Outside-in-liquid atomizer, Spray unsteadiness, Spray characteristics, Flow regime map
Released
09.01.2021
Publisher
Elsevier Ltd.
Location
The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, UK
ISSN
1359-4311
Volume
187
Number
1
Pages from–to
1–18
Pages count
18
BIBTEX
@article{BUT168043,
author="Farid A. {Hammad} and Kai {Sun} and Zhizhao {Che} and Jan {Jedelský} and Wang {Tianyou},
title="Internal two-phase flow and spray characteristics of outside-in-liquid twin-fluid atomizers",
year="2021",
volume="187",
number="1",
month="January",
pages="1--18",
publisher="Elsevier Ltd.",
address="The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, UK",
issn="1359-4311"
}