Abstract

Pressure swirl atomizers are widely employed in various industrial applications such as aerospace propulsion, power generation and agricultural spray systems, owing to their ability to produce fine, widespread sprays essential for efficient combustion, crop treatment and emission control. The geometry of the atomizer orifice plays a crucial role in determining spray characteristics, including droplet size distribution, spray cone angle, velocity and atomization efficiency. This review synthesizes recent experimental and computational studies focusing exclusively on how orifice geometry-shape, dimensions and internal features-influences spray behaviour. It examines how variations in orifice diameter, length, shape (conical, profiled, plain) and geometric ratios (such as length-to-diameter) affect atomization quality, spray angle, droplet size and flow patterns. The review highlights that larger orifice diameters tend to reduce swirling velocity and increase droplet size, while optimized geometric ratios can enhance spray uniformity and atomization efficiency. Deviations from ideal orifice shapes, such as inclined or convergent/divergent profiles, significantly impact internal flow patterns and resulting spray characteristics. Understanding these effects is vital for designing more efficient atomizers tailored to specific industrial needs. The study underscores the importance of precise orifice design to optimize spray quality, improve combustion performance and minimize emissions, thus contributing to advancements in atomizer technology.

Keywords:Spray; Pressure swirl atomizer; Orifice; Geometry