円形噴流のサイドジェットの形成とノズル出口での速度勾配の関係

抄録

Side jets are radial ejections formed at the initial region of a jet. It is known that the side jets are generated in a sufficiently low density jet. However, it was recently found that the side jets are formed in the initial region of a round jet when the density ratio is unity. A relationship between the side-jets formation and the non-dimensional velocity gradient is experimentally examined in isothermal air jets. The value of non-dimensional velocity gradient at the nozzle exit has lower and upper limits for the side-jets formation. Also, there is hysteresis in the values of the lower and upper limits.