Fundamental study on transport phenomena on jets toward their control by streamwise vortices

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K04264
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 19010:Fluid engineering-related
• Research Institution: Nagoya University
• Principal Investigator: Ito Yasumasa 名古屋大学, 工学研究科, 教授 (40346078)
• Co-Investigator(Kenkyū-buntansha): 酒井 康彦 公益財団法人名古屋産業科学研究所, 研究部, 上席研究員 (20162274) ; 岩野 耕治 名古屋大学, 工学研究科, 助教 (20750285)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: Jet / Mixing / Diffusion / Control

Outline of Final Research Achievements

The research aimed to elucidate the fundamental structure of turbulent flows centered around jets and control the mixing and diffusion through innovative design of the initial velocity distribution of the jet. The study primarily relied on numerical simulations. Specifically, it aimed to reveal the turbulent energy and scalar transport mechanisms across vortex scales in quasi-uniform isotropic turbulence and shear turbulent flows. The research also involved jet control using vortex generators and optimal control of the initial jet velocity distribution through deep reinforcement learning.
The results identified desirable initial velocity distributions for promoting or suppressing mixing and diffusion in jets. Furthermore, the physical mechanisms behind them were elucidated.
Overall, the research contributed to the understanding of turbulent flows and provided insights into controlling mixing and diffusion.

Free Research Field

流体工学

Academic Significance and Societal Importance of the Research Achievements

噴流はエンジン，エアコンなど幅広い流体機器にみられる現象であり，その基礎構造の解明および最適化は，高エネルギー効率・低環境負荷機器の開発に不可欠である．本研究では最も一般的な噴流制御手法である初期流速分布の最適化に焦点を当て，それにより引き起こされる縦渦など二次流れを利用した噴流制御法の最適化を行った．本研究より，初期流速分布を特殊な形状とすることで，通常の噴流とは大きく異なる統計的性質を有する噴流が形成されることが明らかになった．これは従来では実現が困難であった特性を有する噴流の実現可能性を示しており，今後の工学応用が期待される．