Study on structures of turbulent heat transfer phenomena in nonsimilarity fields with combined forces and reconstruction of turbulent heat transfer model

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K06195
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Thermal engineering
• Research Institution: Nagoya Institute of Technology
• Principal Investigator: Hattori Hirofumi 名古屋工業大学, 工学(系)研究科(研究院), 技術職員 (30467352)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 熱伝達 / 乱流 / 数値計算 / 複合外力 / 非相似場

Outline of Final Research Achievements

In this study, the nonsimilarity turbulent heat transfer phenomena between velocity and thermal fields in both the inner flow (such as a pipe flow) and the outer flow (such as a boundary layer with thermal stratification) with combined external forces such as the buoyancy, the pressure gradient etc. have been explored using the direct numerical simulation (DNS) which is the highest accuracy numerical simulation method for the analyses of turbulent heat transfer phenomena. As the results, both instantaneous and statistical turbulent data in various nonsimilarity turbulent heat transfer phenomena with combined external forces are successfully obtained by the DNS, and the characteristics structure and mechanism in such complex turbulent heat transfer phenomena are revealed using the obtained DNS data. Also, the turbulent heat transfer model for the prediction of predict nonsimilarity turbulent heat transfer phenomena with combined external forces is reconstructed using DNS data.

Free Research Field

伝熱工学，乱流力学，数値流体工学

Academic Significance and Societal Importance of the Research Achievements

現実の乱流熱伝達場においては，速度場と温度場が非相似形となり，かつ様々な外的要因が作用するために複雑な場が形成され，その解析は困難を極める．そのため，外的要因を分割し，個々の要因の影響について調査した乱流熱伝達研究は多数見られるが，複数の要因を合理的に考えて調査した研究は希少であり，それらを系統的に解明したことによる学術的意義は高い．また，熱流体現象を利用する機器の設計において，そこにおける複雑な乱流熱伝達場を精度良く予測することが，より機器の熱効率等を向上させることとなるが，本研究では，より精度の高い乱流熱伝達予測モデルを再構築したことにより，社会的な意義も併せ持つ．