Atomization characteristics of a bluff body-assisted sonic twin-fluid atomizer. Issue 3 (September 2022)

• Record Type: Journal Article
• Authors: Sikka, Raghav; Vågsæther, Knut; Bjerketvedt, Dag; Lundberg, Joachim
• Is Part Of: International journal of spray and combustion dynamics. Volume 14:Issue 3/4(2022)
• Page Start: 199
• Page End: 217
• Publication Date: 2022-09
• Subjects: bluff body-assisted atomizers -- droplet size distribution -- relative span factor -- bluff body dynamics -- high-speed flows; Combustion engineering -- Periodicals; Fluid dynamics -- Periodicals; Combustion -- Periodicals; Spraying -- Periodicals; Combustion; Combustion engineering; Fluid dynamics; Spraying; Periodicals; 541.361
• DOI: 10.1177/17568277221104924
• Languages: English
• ISSNs: 1756-8285

Abstract

This study examines the gas dynamic effect and atomization behaviour of the sonic bluff body-assisted twin-fluid atomizer with three distinct geometry configurations based on cone distances (Lc ) as 6.0 mm, 8.0 mm, and 10.0 mm. The atomization characteristics of these atomizers employing a 280 µm annular liquid sheet with a central bluff body (cone) are compared based on a range of air and liquid flow rates. The spray-bluff body impacted secondary atomization was characterized through volume-normalized droplet size distribution (DSD) & cumulative droplet distribution, excentricity plots, Sauter mean diameter (SMD), and relative span factor (Δ). When plotted for a given liquid flow rate, the DSD & cumulative droplet distribution becomes more uniform with the increase in the airflow rate independent of the cone distance (Lc ). Excentricity plots exhibited high excentricity droplets at the spray centreline and a large fraction of nearly spherical droplets at off-centre spray locations. SMD and RSF (Δ) showed opposite trends when plotted against the air-to-liquid ratio (ALR) as SMD increases while RSF decreases with radial locations, respectively. When plotted for all radial locations, Sauter mean diameter (D32) and relative span factor (Δ) show a cluster formation. Larger SMD values correspond to lower RSF (Δ) values and vice-versa.