The scale effects on the dynamic behavior of hydrogen-air lean premixed flames under the adiabatic and non-adiabatic conditions

Satoshi Kadowaki, Tsutomu Uchiyama, Toshiyuki Katsumi, Hideaki Kobayashi

Research output: Contribution to conferencePaperpeer-review

Abstract

To come into practical use of lean combustion of hydrogen-air mixture, we need to obtain the fundamental knowledge on the dynamic behavior of premixed flames. This behavior is mainly caused by intrinsic instability and is strongly affected by the scale effects and heat loss. In this study, we performed numerical calculations of two-dimensional unsteady reactive flow to reveal the scale effects on the dynamic behavior of hydrogen-air lean premixed flames under the adiabatic and non-adiabatic conditions. We used the calculation model containing the detailed hydrogen-oxygen combustion, compressibility, viscosity, heat conduction, molecular diffusion and heat loss of Newtonian type. To study the scale effects on the dynamic behavior, sinusoidal disturbances were superimposed on planar flames. The superimposed disturbances evolved owing to intrinsic instability, and then the cellular flame fronts formed. As the heat loss became larger, the burning velocity of cellular flames decreased owing to the reduction of thermal expansion. On the other hand, the normalized burning velocity of cellular flames under the non-adiabatic conditions was large compared with the adiabatic flames, which denoted that the heat loss promoted instability. Moreover, the scale effects had a great influence on the dynamic behavior of flame fronts. The burning velocity of cellular flames increased monotonically as the scale size became larger. This indicated that the long-wavelength components of disturbances affected the dynamic behavior of cellular premixed flames.

Original languageEnglish
Publication statusPublished - 2019 Jan 1
Event12th Asia-Pacific Conference on Combustion, ASPACC 2019 - Fukuoka, Japan
Duration: 2019 Jul 12019 Jul 5

Conference

Conference12th Asia-Pacific Conference on Combustion, ASPACC 2019
Country/TerritoryJapan
CityFukuoka
Period19/7/119/7/5

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Energy Engineering and Power Technology
  • Fuel Technology
  • Condensed Matter Physics

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