Study on Flow characteristics of Swirling Jet Issuing into Circular Channel

本文研究了旋转射流进入圆柱通道的流动特性。由于旋流射流的喷嘴出口远离通道的中心线，因此射流在通道壁的影响下朝向通道弯曲。在本研究中，空气射流被用作旋转射流，并且一端封闭的丙烯酸树脂管也被用作圆柱形通道。在此基础上，进行了变旋数旋转射流的实验研究。在该装置中，多个叶片围绕圆形喷嘴布置，并且通过控制这些叶片的角度来不同地改变旋流数。此外，在实验装置中，喷嘴的中心轴线与圆形通道之间的差距是可控的。研究结果表明：（1）当产生旋转射流的喷嘴远离圆形通道中心线时，由于旋转射流卷吸的不平衡，射流流向通道壁面弯曲。(2)当差距的大小超过一定值时，旋转射流中心线的倾角趋于恒定。从这一事实，它已被澄清，存在的流动的相似性。(3)随着旋流数的增加，射流中心线的倾角变大。

This study is on the flow characteristics of the swirling jet issuing into the cylindrical channel. Since the nozzle exit of the swirling jet is placed apart from the centerline of the channel, the jet flow curves toward the channel under the influence of the channel wall. In this study, the air jet flow is used as the swirling jet and the acrylic resin pipe whose one end is closed is also done as the cylindrical channel. Furthermore, the swirling jet generating where the swirl number is changeable has been made in this study. In this device the several vanes are arranged around the circular nozzle and the swirl number is changeable variously by controlling the angle of these vanes. Moreover, in the experimental equipment the gap between the center axes of the nozzle and the circular channel is controllable. The results in this study are as follows ;(1) In the case that the nozzle issuing the swirling jet is placed apart from the centerline of the circular channel, the jet flow curves toward the channel wall because of the imbalance of the entrainment of the swirling jet.(2) When the quantity of the gap exceeds a certain value, the inclination of the centerline of the swirling jet becomes constant. From this fact, it has been clarified that there exists a similarity of the flow.(3) As the swirling number increases, the inclination of the jet centerline becomes large.