Effects of secondary breakup, collision dynamics, gravity and evaporation on droplet size distribution in a pressure-swirl JET A-1 spray

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26210%2F24%3APU150024" target="_blank" >RIV/00216305:26210/24:PU150024 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0016236123027175" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0016236123027175</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.fuel.2023.130103" target="_blank" >10.1016/j.fuel.2023.130103</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Effects of secondary breakup, collision dynamics, gravity and evaporation on droplet size distribution in a pressure-swirl JET A-1 spray

Popis výsledku v původním jazyce

Size and velocity of droplets in pressure-swirl sprays vary with distance downstream the nozzle. This study aims to explain the phenomena contributing to size-resolved spatial variation of the drop size distribution for Jet A-1 spray from a small pressure swirl atomizer injected into quiescent ambient air at atmospheric conditions. The effects of secondary breakup, droplet collisions, gravity, drag-driven spray dispersion, and evaporation are evaluated. Phase Doppler anemometer (PDA) was used to resolve the velocity and size of the droplets in radial profiles at several axial distances (Z) from the nozzle exit at injection pressures between 0.5 and 1.5 MPa. The droplet motion and collision dynamics were qualitatively characterised by high-speed imaging. The analysis focused on areas along 1) the spray axis and 2) the liquid sheet direction. The first area covers small droplets with marginal evolution, while the mean drop size in the second area significantly increases downstream. The local drop size distribution and its axial evolution results from a combined effect of ballistic filtering (drifting of small droplets from periphery to spray centre and large droplets vice versa), centrifugal and turbulent droplet dispersion, and droplet collisions (increasing drop size with distance). The relative droplet-gas velocity was found at investigated Z positions too small for drag-driven secondary droplet breakup to occur. Evaporation of Jet A-1 sprayed at room temperature and pressure into still atmosphere reduces the drop size marginally. Trajectory of all drop sizes is insignificantly altered by gravity. The smallest droplets are strongly drag-driven to the spray axis, while large ones disperse centrifugally and have sufficient momentum to neglect the gravity. Combining results from imaging and laser diagnostics, various collision outcomes were identified, with a conclusion that these depend on the size and velocity of colliding droplets. Coalescing collisions dominate an

Název v anglickém jazyce

Effects of secondary breakup, collision dynamics, gravity and evaporation on droplet size distribution in a pressure-swirl JET A-1 spray

Popis výsledku anglicky

Size and velocity of droplets in pressure-swirl sprays vary with distance downstream the nozzle. This study aims to explain the phenomena contributing to size-resolved spatial variation of the drop size distribution for Jet A-1 spray from a small pressure swirl atomizer injected into quiescent ambient air at atmospheric conditions. The effects of secondary breakup, droplet collisions, gravity, drag-driven spray dispersion, and evaporation are evaluated. Phase Doppler anemometer (PDA) was used to resolve the velocity and size of the droplets in radial profiles at several axial distances (Z) from the nozzle exit at injection pressures between 0.5 and 1.5 MPa. The droplet motion and collision dynamics were qualitatively characterised by high-speed imaging. The analysis focused on areas along 1) the spray axis and 2) the liquid sheet direction. The first area covers small droplets with marginal evolution, while the mean drop size in the second area significantly increases downstream. The local drop size distribution and its axial evolution results from a combined effect of ballistic filtering (drifting of small droplets from periphery to spray centre and large droplets vice versa), centrifugal and turbulent droplet dispersion, and droplet collisions (increasing drop size with distance). The relative droplet-gas velocity was found at investigated Z positions too small for drag-driven secondary droplet breakup to occur. Evaporation of Jet A-1 sprayed at room temperature and pressure into still atmosphere reduces the drop size marginally. Trajectory of all drop sizes is insignificantly altered by gravity. The smallest droplets are strongly drag-driven to the spray axis, while large ones disperse centrifugally and have sufficient momentum to neglect the gravity. Combining results from imaging and laser diagnostics, various collision outcomes were identified, with a conclusion that these depend on the size and velocity of colliding droplets. Coalescing collisions dominate an

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

<a href="/cs/project/GA22-17806S" target="_blank" >GA22-17806S: Pokročilé systémy s kapalnými filmy a spreji pro čištění a sorpci plynů</a><br>

Návaznosti

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

Rok uplatnění

2024

Kód důvěrnosti údajů

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

Název periodika

FUEL

ISSN

0016-2361

e-ISSN

1873-7153

Svazek periodika

359

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

21

Strana od-do

1-21

Kód UT WoS článku

001126172100001

EID výsledku v databázi Scopus

2-s2.0-85182209865