Flow Characteristics of Multiple Round Jets Issuing from In-line Nozzle Arrangement

Abstract

This research reports on an experimental investigation of the flow characteristics of multiple round jets issuing from 6 × 6 in-line nozzle arrangement at low-Reynolds number, Re ≈ 4 × 103, with five spacing ratios of l/d = 1.5, 2, 3, 4 and 5 (where d is a diameter of nozzle, and l is a spacing between the center of nozzles). The mean and fluctuating velocities of the jet flow were measured by constant-temperature type hot-wire anemometer. We found that the bending of the outside jet decreases with increasing the spacing ratio l/d. In the further downstream, the multiple jets merge into a single jet flow and the merging of multiple jets occur more downstream with increasing the spacing ratio l/d. In the case of the small spacing ratio, the maximum velocity of merged jet increases and the merged jet spreads from the near field of jet exit.