円形噴流に形成した分岐流れとその渦構造

第54回流体力学講演会/第40回航空宇宙数値シミュレーション技術シンポジウム (2022年6月29日-7月1日. いわて県民情報交流センター(アイーナ)), 盛岡市, 岩手

The 54th Fluid Dynamics Conference / the 40th Aerospace Numerical Simulation Symposium (June 29 - July 1, 2022. Iwate Citizen Information Exchange Center (Aiina)), Morioka, Iwate, Japan

The formation of a side jet in the initial region of a round jet is concerned with the wavy deformation of a vortex ring and a pair of streamwise vortices. These phenomena are difficult to investigate to be unstable, and the details are not clear. Therefore, this study aims to clarify the formation mechanism of side jets. To achieve this, we fixed the forming positions of the side jets by controlling both the wavy deformation of the vortex ring and the formation of streamwise vortices, using synthetic jets installed in a round nozzle. The following became clear from the controlled experiment and its numerical simulation. The side jets occur due to the secondary instability that develops in the braid region. The side jet is the flow induced outwardly in the radial direction by the circulations of a vortex ring and a pair of streamwise vortices. The apparently continuous flow of a side jet results from the periodic repetition of induced flow between vortex rings and the streamwise vortices.

形態: カラー図版あり

Physical characteristics: Original contains color illustrations

資料番号: AA2230023025

レポート番号: JAXA-SP-22-007