Investigation of Fine-scale Scalar Mixing in High Reynolds Number Turbulent Jets

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K05817
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Fluid engineering
• Research Institution: Japan Aerospace EXploration Agency
• Principal Investigator: Matsuyama Shingo 国立研究開発法人宇宙航空研究開発機構, 航空技術部門, 研究開発員 (60392841)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 乱流噴流 / スカラー混合 / 高レイノルズ数乱流 / DNS / LES

Outline of Final Research Achievements

In this research, direct numerical simulations of a turbulent plane jet were performed to clarify the role of very small-scale turbulence in the scalar mixing process of high Reynolds (Re) number jet. By analyzing the results at Re = 3000, 10000, 30000, we evaluated the Re-dependence of turbulent scalar mixing process. Furthermore, a threshold value of length scale below which a fine-scale turbulence does not affect the mixing process of turbulent jet was evaluated. For this purpose, sub-grid scale (SGS) turbulent kinetic energy and scalar variance were evaluated by filtering the DNS data, and compared with the grid scale (GS) components. The results showed that the turbulent length scales up to 60, 110, and 170 times of Kolmogorov scale are important in the scalar mixing process of jet, for Re = 3000, 10000, and 30000, respectively.

Free Research Field

乱流工学