Dynamics of interactions between thermodynamic properties and wall turbulence in supercritical fluids and quantification of uncertainty

2017 Fiscal Year Final Research Report

• Project/Area Number: 26709066
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Partial Multi-year Fund
• Research Field: Aerospace engineering
• Research Institution: Tohoku University (2015-2017); Japan Aerospace Exploration Agency (2014)
• Principal Investigator: Kawai Soshi 東北大学, 工学研究科, 准教授 (40608816)
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: 航空宇宙流体力学 / 数値流体力学 / 流体工学 / 超臨界流体 / 実在流体効果 / 乱流境界層 / DNS / 乱流モデル

Outline of Final Research Achievements

In this study, an accurate and robust numerical method for simulating transcritical turbulent flows at supercritical pressure is proposed, and fully-developed transcritical turbulent boundary layers (TBLs) at supercritical pressures are studied by solving the full compressible Navier-Stokes equations using direct numerical simulation (DNS). From the DNS results, besides the mean thermodynamic property variations, different from the conventional ideal-gas TBLs, significant density fluctuations that originate from the strong real fluid effects and the mechanisms of the non-negligible interactions between the real fluid effects and wall turbulence are identified in the transcritical TBLs. Then, based on the DNS analysis, a RANS model that accounts for the effects of density fluctuations is proposed, which improves the prediction accuracy of the TBLs at supercritical pressure, something that existing RANS models fail to do robustly.

Free Research Field

航空宇宙工学、流体力学、数値流体力学