Detail publikace

Droplet dynamics in internally mixed twin-fluid spray

JEDELSKÝ, J. JÍCHA, M.

Originální název

Droplet dynamics in internally mixed twin-fluid spray

Typ

článek ve sborníku ve WoS nebo Scopus

Jazyk

angličtina

Originální abstrakt

Effervescent atomizers are based on mixing of gas with liquid prior to discharge. We describe the discharge of two-phase mixture and movement of droplets in gas jet using simple theoretical models, following with elucidation of droplets dynamics using experimental data for an effervescent spray. Discharge of the liquid-gas flow from the nozzle is described using a combination of two discharge models. Depending on operation conditions, 59–64% of the total discharged mass corresponds to Separated Flow Model and the rest to Homogeneous Flow Model. Discharge velocity of the liquid reaches 12–27% of the gas exit velocity. The liquid-gas velocity ratio is negatively correlated with gas-to-liquid mass ratio (GLR) and positively correlated with inlet pressure. Radial profiles of axial droplet velocity, as measured using Phase Doppler anemometry, are axisymmetric bell-shaped with a maximum in the centreline analogous to the profile defined for a simple gas jet which however is more flat near the centreline and decline much faster for higher radial positions. Mean velocity in particular spray position varies with particle size within a range of several m/s typically. This variation is closely related with particle Stokes number, Stk. Variation of mean velocity with operation pressure and GLR can be explained with discharge conditions; higher pressures and GLRs lead to higher discharge velocities that are reflected in the spray downstream. Stokes numbers are generally << 1 for particle sizes Dp up to 10 um so they smoothly follow the gas flow. Stk for size 10 um 10 and very weakly interact with the gas.

Klíčová slova

droplet dynamics, internally mixed twin-fluid atomization, effervescent atomization, spray structure, dispersed two-phase flow.

Autoři

JEDELSKÝ, J.; JÍCHA, M.

Rok RIV

2014

Vydáno

1. 7. 2014

Nakladatel

WIT Press

Místo

A Coruňa, Spain

ISBN

978-1-84564-791-9

Kniha

Advances in Fluid Mechanics X

ISSN

1743-3533

Periodikum

WIT Transactions on Engineering Sciences

Ročník

2014

Číslo

82

Stát

Spojené království Velké Británie a Severního Irska

Strany od

227

Strany do

238

Strany počet

12

URL

http://www.witpress.com/elibrary/wit-transactions-on-engineering-sciences/82/27290

BibTex

@inproceedings{BUT111226,
  author="Jan {Jedelský} and Miroslav {Jícha}",
  title="Droplet dynamics in internally mixed twin-fluid spray",
  booktitle="Advances in Fluid Mechanics X",
  year="2014",
  journal="WIT Transactions on Engineering Sciences",
  volume="2014",
  number="82",
  pages="227--238",
  publisher="WIT Press",
  address="A Coruňa, Spain",
  doi="10.2495/AFM140201",
  isbn="978-1-84564-791-9",
  issn="1743-3533",
  url="http://www.witpress.com/elibrary/wit-transactions-on-engineering-sciences/82/27290"
}