Elucidation of mechanism of combustion noise generation and modulation from turbulent lean premixed swirling flame

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H02076
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 19020:Thermal engineering-related
• Research Institution: Kyoto University
• Principal Investigator: Kurose Ryoichi 京都大学, 工学研究科, 教授 (70371622)
• Co-Investigator(Kenkyū-buntansha): 立花 繁 国立研究開発法人宇宙航空研究開発機構, 航空技術部門, 上席研究開発員 (50358496) ; 横森 剛 慶應義塾大学, 理工学部(矢上), 教授 (90453539)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 燃焼騒音 / 希薄予混合火炎 / 旋回火炎 / 水素燃焼 / 乱流 / 壁面 / 計測 / 数値シミュレーション

Outline of Final Research Achievements

In this study, the generation and modulation mechanism of combustion noise was investigated both by sophisticated experiment and high-fidelity numerical simulation in detail, especially for the effect of wall. The results showed that the peaks of the Sound Pressure Level (SPL) spectrum of combustion noise become obscure due to the presence of the wall, and the characteristics change depending on the distance between the wall and flame. This is considered to be due to the facts that the flame shape and therefore the characteristics of direct sound waves from the flame change when the flame attaches the wall, and/or that the direct sound waves are interfered by the reflected waves from the wall. In addition, the numerical approach developed in this study was proven to be capable of precisely predicting the effect of wall on the combustion nose characteristics.

Free Research Field

熱流体工学

Academic Significance and Societal Importance of the Research Achievements

燃焼騒音に関する研究の歴史は古く，数多くの研究が存在するが，そのほとんどは火炎から直接発生する直接燃焼騒音に関するものであり，壁面や周囲乱流渦等の外的因子の影響を受けて変調する間接燃焼騒音に関するものは極めて数少ない．本研究は，間接燃焼騒音の中でも特に取り扱いが困難な壁面の影響に着目し，そのメカニズムの一端を明らかにしたものであり，学術的意義は極めて高い．また，本研究において確立した数値解析手法は，様々な燃焼機器から生じる燃焼騒音，ひいては燃焼振動の特性を高精度に予測可能であり，脱炭素社会の実現につながる水素燃料利用促進技術の開発にも大いに役立つことが期待できるため，本研究の社会的意義も高い．