Effect of spill orifice geometry on spray and control characteristics of spill-return pressure-swirl atomizers

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26210%2F19%3APU132038" target="_blank" >RIV/00216305:26210/19:PU132038 - isvavai.cz</a>

Result on the web

<a href="https://www.sciencedirect.com/science/article/pii/S0894177718319964?dgcid=author" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0894177718319964?dgcid=author</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.expthermflusci.2019.04.014" target="_blank" >10.1016/j.expthermflusci.2019.04.014</a>

Result language

angličtina

Original language name

Effect of spill orifice geometry on spray and control characteristics of spill-return pressure-swirl atomizers

Original language description

Many spray process technologies require variable liquid flow rates or droplet sizes. Frequently used Simplex atomizers, favoured for their simple construction, reliability and fine spray, have a limited regulation range due to their flow rate dependency on the square root of the inlet overpressure, pl. To overcome this drawback, spill-return versions of the atomizer were developed in the past but so far rarely investigated in depth. In this paper, small spill-return atomizers (SRAs) were designed and investigated experimentally using Phase Doppler Anemometry (PDA) and high-speed imaging with the aim to determine the effect of the spill orifice design, e.g. the positioning of the axial and off-axis spill orifices, their number and inclination on the control characteristics, nozzle efficiency and spray characteristics. Such detailed data were not to be found in the open literature. The off-axial spill orifice version produced a stable spray under all flow regimes investigated while the axially positioned spill orifice provided an unstable spray for low spill-to-feed ratios (SFR). However, the axially placed spill orifice was found to be more energy efficient as it required a lower spill flow rate to achieve the same injection flow rate. The radial position of the spill orifices affected the turndown ratio and liquid breakup nature. The atomizers with spill orifices placed close to the swirl chamber centreline generated a liquid sheet which disintegrated in short-wave breakup mode while the other atomizers demonstrated a long-wave breakup mode. This mode produced longer liquid breakup length and formed droplets with smaller Sauter mean diameters. Atomization efficiency was found to decrease linearly with SFR and almost inversely proportional to pl. These findings have produced practical guidelines and recommendations for atomizer designs to suit specific goals and are addressed to both atomizer designers and application engineers. The experimental data form a signific

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10305 - Fluids and plasma physics (including surface physics)

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2019

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

EXPERIMENTAL THERMAL AND FLUID SCIENCE

ISSN

0894-1777

e-ISSN

1879-2286

Volume of the periodical

106

Issue of the periodical within the volume

1

Country of publishing house

US - UNITED STATES

Number of pages

12

Pages from-to

159-170

UT code for WoS article

000471733400014

EID of the result in the Scopus database

2-s2.0-85065089538