Air–liquid interactions in a pressure-swirl spray

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26210%2F18%3APU126204" target="_blank" >RIV/00216305:26210/18:PU126204 - isvavai.cz</a>

Result on the web

<a href="https://www.sciencedirect.com/science/article/pii/S001793101735024X" target="_blank" >https://www.sciencedirect.com/science/article/pii/S001793101735024X</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.ijheatmasstransfer.2018.01.003" target="_blank" >10.1016/j.ijheatmasstransfer.2018.01.003</a>

Result language

angličtina

Original language name

Air–liquid interactions in a pressure-swirl spray

Original language description

The energy transfer between a liquid hollow cone spray and the surrounding air has been studied using both imaging and phase-Doppler techniques. The spray was produced by a pressure-swirl atomizer discharging Jet A-1 fuel at inlet over pressures of dp = 0.5, 1.0 and 1.5 MPa into quiescent ambient air. The liquid exits the nozzle as a conical film which thins as it spreads and develops long- and short-wave sinusoidal instabilities with breakup occurring, at the length smaller than that predicted by the inviscid model, to form film fragments and ultimately droplets downstream the spray. The single shot imaging characterised the spray regions of near-nozzle flow, the breakup processes and the developed spray. The phase-Doppler system resolved the three components of velocity and size for the droplet flow as measured on radial profiles for four axial distances from the nozzle exit. A Stokes number, Stk, analysis of the droplets’ response times to the airflow time-scales showed that droplets < 5 µm followed the airflow faithfully and so were used to estimate the local airflow velocity. This allowed a comparison of both the droplet and airflow fields in terms of their mean and fluctuating velocity components to be made. The formation of the hollow cone spray and the interaction of the fragments and droplets with the air, through viscous drag, induce complex entrained airflows. The airflow was found to be highly anisotropic, fluctuating preferentially in the downstream direction, and spatially varying within three distinct spray regions. The air drag establishes a positive size–velocity correlation of droplets; their Stk reduces with axial distance and increases with droplet size and dp; so that Stk ≈ 1 for 20–40 µm droplets and the largest droplets (80–160 µm, Stk > 10) move ballistically. The spatially resolved mean and turbulent kinetic energies of the air and spectra of the droplet velocity fluctuations are detailed in the paper. These findings are relevant to scientis

Czech name

—

Czech description

—

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

121

Issue of the periodical within the volume

6

Country of publishing house

GB - UNITED KINGDOM

Number of pages

17

Pages from-to

788-804

UT code for WoS article

000430030300068

EID of the result in the Scopus database

2-s2.0-85041655496