Experimental Study of Atomization Feature of Coaxial Parallel Flow Airspray Nozzle in Crossflow

To improve the atomization efficiency of the direct injection nozzle, a ring-shaped air layer is enveloped on the outer side of the liquid jet, forming a structure of co-flowing air atomization nozzle with liquid and gas phases. This paper experimentally studies its atomization characteristics when subjected to cross-flow injection in lateral air streams. The effects of ring-shaped air channel height (0.4mm, 0.7mm, 1.0mm, 1.3mm), different lateral air flow velocities (28.7m/s, 35.9m/s, 43.1m/s), and liquid flow rates (2.5g/s, 4.72g/s, 6.94g/s) on the atomization performance of the nozzle were investigated. Pulsed laser was used as the light source to obtain clear transient images of the liquid spray field. Marvin laser particle size analyzer was employed to measure the particle size at different locations in the liquid spray field. With the constant momentum flux ratio of the liquid-gas jet ensured, a larger ring-shaped air channel height leads to a stronger atomization enhancement effect, resulting in a smaller SMD (Sauter Mean Diameter) of the liquid spray field. The ring-shaped air significantly reduces the influence of lateral air flow velocity and liquid flow rate on the distribution area of the liquid spray field.