Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 11, 2020 - November 13, 2020
A jet flow is one of the most basic fluid flow used in industrial field and used for heating, cooling and mixing process. The properties and characteristics of diffusion and mixing of the jet flow strongly depend on the large-scale vortex structures formed in the near-field. Thus, an appropriate control method of a turbulent jet flow is important research topic in fluid mechanics to enhance diffusion and mixing efficiency. Recently, attention has been paid to blooming jet realized with superimposition of axial and helical excitations on the inlet velocity profile, and detailed characteristics of control parameters have been clarified. We demonstrated that the blooming jet also can be realized by a mechanical precessing nozzle with axisymmetric excitation. However, the detail structure of the blooming jet has not been clarified. To improve these performances, it is also indispensable to elucidate the details of the jet diffusion. In this study, we analyzed the detail flow characteristics of the blooming jet using dynamic mode decomposition (DMD) method. It was revealed that the effect of both the axial excitation and the nozzle precession extends to the downstream.
