Non-modal stability of vortices and by-pass transition: towards general theory of hydrodynamic stability

2014 Fiscal Year Final Research Report

• Project/Area Number: 24540391
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Mathematical physics/Fundamental condensed matter physics
• Research Institution: Tohoku University
• Principal Investigator: HATTORI Yuji 東北大学, 流体科学研究所, 教授 (70261469)
• Co-Investigator(Renkei-kenkyūsha): FUKUMOTO Yasuhide 九州大学, マス・フォア・インダストリ研究所, 教授 (30192727) ; IWAKAMI Wakana (中野 わかな) 京都大学, 基礎物理学研究所, 研究員 (50571535)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 渦 / 非モード安定性 / バイパス遷移 / 遷移的成長 / WKB安定性解析 / 流れの安定性理論

Outline of Final Research Achievements

Vortices are one of the fundamental structures in various flows. The stability of vortices is the starting point in understanding the nature of the flow. Transient growth and destabilization by localized disturbances in vortices are studied theoretically and numerically in order to understand the transition to turbulence in vortical flows. In transient growth vortex stretching by straining flow is shown to be a key mechanism. Numerical results of unstable growth of localized disturbances are in good agreement with theoretical prediction. The transition to turbulence occurs after several stages of growth.

Free Research Field

流体物理学, 数値流体工学