Formulation of dispersed phase combustion physics at low pressure for evaluation of engine high-altitute relight performance

2014 Fiscal Year Final Research Report

• Project/Area Number: 24360350
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Aerospace engineering
• Research Institution: Yamaguchi University
• Principal Investigator: MIKAMI Masato 山口大学, 理工学研究科, 教授 (20274178)
• Co-Investigator(Kenkyū-buntansha): SEO Takehiko 山口大学, 大学院理工学研究科, 准教授 (00432526)
• Co-Investigator(Renkei-kenkyūsha): KIKUCHI Masao 宇宙航空研究開発機構, 宇宙科学研究所, 研究員 (80371144) ; MORIUE Osamu 九州大学, 大学院工学研究員, 准教授 (70363124)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 燃焼 / 液滴 / 燃え広がり / 低圧

Outline of Final Research Achievements

This research conducted microgravity experiments of flame spread over fuel-droplet arrays at a low pressure in order to improve understanding of the flame spread in fuel sprays under high-altitude relight condition of jet engines. The results show that both the flame-spread rate and flame-spread limit distance at the low pressure are greater than those at atmospheric pressure. The pressure effect on the flame-spread rate was discussed considering some elementary processes, such as droplet heating and thermal diffusion. The thermal diffusion speed is inversely proportional to the pressure. The pressure effect on the flame-spread limit distance was discussed considering transient process of high-temperature region around a burning droplet. The maximum radius of the outer edge of the high-temperature region is proportional to -1/3 power of the ambient pressure. Group combustion occurrence was also demonstrated with a percolation model considering the flame-spread limit.

Free Research Field

燃焼工学