A study on the velocity characteristics of the liquid elements produced by two impinging jets

Abstract

In this study, the velocity characteristics of liquid elements (ligaments for high-speed jets and droplets for low-speed jets) formed by two impinging jets were analyzed using a double-pulse image capturing technique. The velocities of liquid elements were high at low azimuthal angles but then decreased with an increase in the azimuthal angle. The rate of velocity decrease was higher for the droplets. The magnitude of the maximum velocities of ligaments and droplets observed around the axis of the spray was close to the corresponding jet velocity, which is consistent with the previous assumption that the velocities of liquid elements are equal to the jet velocity. With an increase in the impingement angle, the velocities of liquid elements at low azimuthal angles decreased due to the decreased vertical momentum of the pre-impacting jets. Based on the above results, more refined analytical work for the spray velocity is required because the velocities of liquid elements are affected by the impingement angle and they are locally different instead of being uniform across the region. The shedding angles of liquid elements increased linearly but at a slightly lower value than the azimuthal angle, which implies that the direction of movement of the liquid elements is almost disposed radially about the impingement point.