Author Identifier (ORCID)
Farzad Hossain: https://orcid.org/0000-0001-8256-8553
Yasir M. Al-Abdeli: https://orcid.org/0000-0001-5672-9448
Mehdi Khiadani: https://orcid.org/0000-0003-1703-9342
Abstract
Spray-based droplet evaporation systems used in desalination and cooling applications depend on both nozzle arrangement and the interpretation of measured droplet behaviour. This study examines (i) how multi-nozzle configurations differ from single-nozzle characteristics and (ii) how ensemble-averaged measurements change when droplets are separated according to their motion direction (upward or downward). Atmospheric water sprays generated by full-cone spray nozzles were investigated using Particle Image Velocimetry (PIV) for droplet axial velocity measurements and Shadowgraph imaging to determine droplet size and count. Directional filtering was performed using Large Eddy Simulation (LES), validated against experiments. Single- and dual-nozzle configurations were tested with horizontal centre-to-centre spacings (r) of 30 mm, 60 mm, and 120 mm to examine plume interaction. Results show that nozzle spacing (r) strongly governs droplet size, velocity, and plume interaction in multi-nozzle sprays. At r = 30 mm the closer proximity creates larger droplets and strong downward recirculation, while at r = 120 mm sparse spacing produces mostly independent droplet plumes with minimal interaction. The interim r = 60 mm configuration offers the most efficient atomization, with organised interaction and consistent breakup. Directional filtering further reveals clear upward–downward differences: upward droplets stay small and fast, whereas downward droplets grow significantly, especially at r = 60 mm where sizes increase by 25–40% and downward axial velocities reach −2 m/s. These effects weaken at r = 120 mm as plume interaction diminishes. Unfiltered measurements were dominated by downward-moving droplets, demonstrating that directional filtering is essential for accurate characterization of multi-nozzle spray dynamics and for improving spray system design.
Keywords
Atomization efficiency, directional filtering, droplet dynamics, large eddy simulation (LES), multi-nozzle spray, particle image velocimetry (PIV), shadowgraph
Document Type
Journal Article
Date of Publication
6-1-2026
Volume
195
Publication Title
Journal of Aerosol Science
Publisher
Elsevier
School
School of Engineering
Funders
Edith Cowan University / Pawsey Supercomputing Centre with funding from the Australian Government and the Government of Western Australia
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Comments
Hossain, F., Cleary, M. J., Al-Abdeli, Y. M., & Khiadani, M. (2025). Multiple-nozzle sprays: Comparison to single-nozzle sprays and role of directional conditional filtering. Journal of Aerosol Science, 195, 106796. https://doi.org/10.1016/j.jaerosci.2026.106796