Effects of Position of Lateral Jet Injection on Swirling Flow

Abstract

This work presents experimental investigations of the effects of the lateral non-swirling jet injection into a larger swirling flow. The experimental facility comprises a blower with swirling nozzle, non-swirling lateral jet, robotic arm, and hot-wire measurement system. The blower exit area is 4 times larger than that of the lateral jet. Tests were carried out at the initial axial velocity of 25 m/s. Axial and tangential mean velocity profiles were obtained at 5 stations streamwise by using hot-wire anemometry. The swirling flow exhibits a potential core, developing, and fully developed zones seen in the previous literature on the topic. With the lateral jet on, axial and tangential velocities in the core are higher and the flow becomes less oscillatory compared to the jet-off swirling flow, the effects being more pronounced for the axial velocity. The lateral jet deflects the core axis in the swirling flow. In the non-symmetrical lateral jet case, axial velocities are smaller in the core. The lateral jet imparts momentum into the swirling flow increasing its radial size. The core radius increases by 2-4 times compared to that in the baseline case. The angular velocity decreases with the increased distance. With the lateral jet on, the values of angular velocity for the flow converge downstream, where they are approximately 2-3 times smaller than that in the jet-off case.