Time resolved measurements of the fluctuating wall pressure field by a high density MEMS microphone array

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K18010
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Fluid engineering
• Research Institution: Meiji University
• Principal Investigator: Naka Yoshitsugu 明治大学, 理工学部, 専任講師 (10723421)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 乱流計測 / 圧力変動 / 壁乱流

Outline of Final Research Achievements

In this project, a high density digital MEMS microphone array has been newly developed for time resolved measurements of fluctuating wall pressure field. The frequency response of the measurement system was quantitatively evaluated, and the method for background noise treatment was established. The microphone array has been applied to the measurement in a turbulent boundary layer. The two-dimensional distributions of fluctuating pressure reflect the turbulence structures and exhibit intermittent features. Moreover, the statistical characteristics of pressure fluctuation show good agreement with existing results, and the validity of the technique has been confirmed.

Free Research Field

流体工学

Academic Significance and Societal Importance of the Research Achievements

本研究で開発したマイクロフォンアレイにより，壁面圧力変動の空間分布を時系列的に得ることが可能となった。壁面圧力変動の空間分布は，壁面乱流に存在する様々なスケールの乱流構造の寄与を反映しており，乱流構造と壁面圧力変動に関する新たな知見を得ることが期待される。さらに，壁面圧力変動は流体関連振動や空力騒音に関係し，工学的にも重要な物理量である。本マイクロフォンアレイは，測定対象の流れに合わせてマイクロフォンの配置を柔軟に設定することができるため，様々な流れへの応用が期待される。