Internal flow and air core dynamics in Simplex and Spill-return pressure-swirl atomizers

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26210%2F18%3APU127527" target="_blank" >RIV/00216305:26210/18:PU127527 - isvavai.cz</a>

Result on the web

<a href="https://www.sciencedirect.com/science/article/pii/S0017931017356879" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0017931017356879</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.ijheatmasstransfer.2018.02.090" target="_blank" >10.1016/j.ijheatmasstransfer.2018.02.090</a>

Result language

angličtina

Original language name

Internal flow and air core dynamics in Simplex and Spill-return pressure-swirl atomizers

Original language description

Spill-return (SR) atomizers enhance the construction of Simplex atomizers by addition of a passage in the rear wall of the swirl chamber through which the liquid can be spilled away. It allows to discharge the liquid always at a high pressure and to spray well over a wide flow rate range. The spray characteristics of pressure-swirl atomizers are strongly linked to the internal flow, and the air-core dynamics affect the spray stability. The SR atomizers are rarely investigated and their internal flow is not studied at all. Therefore, in this paper, the Simplex and SR atomizers with a central SR orifice were examined comparatively. Transparent polymethyl methacrylate (PMMA) models of both atomizers scaled 10:1 were manufactured for the visualization and velocity measurements of the flow inside the swirl chamber. The atomizers were examined by means of high-speed imaging, laser-Doppler anemometry and computational fluid dynamics tools. The experimental and numerical results were analysed and compared in terms of the spray cone angle (SCA), discharge coefficient (CD), and the morphology and temporal stability of the air core. The internal flow characteristics between the original and the model were matched using the Reynolds, Swirl and Froude numbers. The test conditions were limited to inlet Reynolds numbers from 750 to 1750. The results show that the addition of the spill passage strongly affects the internal flow even when the spill-line is closed. The air core in the Simplex atomizer is fully developed and stable for all flow regimes. The SR atomizer behaved differently; with the closed spill-line (spill-to-feed ratio, SFR = 0), the air core does not form at all; therefore, the spray is unstable. The reason is that the liquid, contained in the spill-line, is drained back into the swirl chamber due to a recirculation zone found inside the spill-line. Increasing the SFR stabilizes the internal flow, and the spray becomes stable if SFR > 0.15. The air core begins to f

Czech name

—

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

2018

Confidentiality

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

Name of the periodical

International journal of heat and mass transfer

ISSN

0017-9310

e-ISSN

1879-2189

Volume of the periodical

123

Issue of the periodical within the volume

1

Country of publishing house

GB - UNITED KINGDOM

Number of pages

10

Pages from-to

805-814

UT code for WoS article

000434887000067

EID of the result in the Scopus database

2-s2.0-85043579555