Dynamic mode decomposition of elliptical liquid jets in crossflow

Abstract

Dynamics of round and elliptical liquid jets in subsonic crossflow is studied using high-speed imaging technique. The experiments are performed at constant gaseous weber number and liquid-gas momentum flux ratio of 6.45 and 17.87 respectively, with orifices of different aspect ratios having an equivalent diameter of 0.43 mm. All cases are carried out inside an open loop subsonic wind tunnel with a test section of 100*100*750 mm. For each case, dynamic modes are generated directly from the snapshots using a variant of Arnoldi method known as the dynamic mode decomposition (DMD). DMD results indicate that elliptical liquid jets have more small-scaled patterns with higher frequencies compared to the case of round liquid jets. As the first attempt to investigate the dynamics of elliptical liquid jets in crossflow, present work captures the dominant spatio-temporal structures. It is also found that the orifice aspect ratio can alter the jet wavelengths remarkably. The extracted data of this work can provide beneficial information on the behaviour of elliptical liquid jets exposed to the gas crossflow in the enhanced capillary breakup regime.

Atomization of liquid pulsed jet in subsonic crossflow

“…Results showed that the penetration depth increased and the droplet size decreased with bigger injection angles. Mokhtarpour et al 22 and Zhou et al 23 both analyzed the cases of elliptical jet and cylindrical jet in air crossflow. The elliptical jet broke up earlier, and with a lower penetration depth, making the atomization even more difficult.…”