On the transition modes and mechanisms for laminar to turbulent lifted jet diffusion flames at normal- and micro-gravity

doi:10.1016/j.combustflame.2023.113269

	On the transition modes and mechanisms for laminar to turbulent lifted jet diffusion flames at normal- and micro-gravity
	Li D(李丹); Wen, Yuzhe; Liu, Yu Cheng; Wang SF(王双峰)
刊名	COMBUSTION AND FLAME
	2024-02-01
卷号	260 页码:10
关键词	Lifted flame Non-premixed jet Transition to turbulence Flame stability Microgravity
ISSN号	0010-2180
DOI	10.1016/j.combustflame.2023.113269
通讯作者	Wang, Shuangfeng(sfwang@imech.ac.cn)
英文摘要	Experiments of laminar-to-turbulent jet diffusion flames were conducted in microgravity (mu g) and normal gravity (ng) to investigate effects of liftoff and buoyancy on the flame transition. Characteristics of flame shape and flame stability during the transitional process as well as the transition mechanism were examined. Theoretical analyses were conducted by considering influences of buoyant flow on flame shape. Results show that for a lifted flame the transition from laminar to turbulent is mainly caused by incipient turbulent flow near the flame base, and the flow turbulence arises from fuel jet breakup developed upstream of the flame. Buoyancy has little effects on the flame transition mechanism. It was found therefore that the ranges of jet Reynolds number corresponding to the transitional stage in ng and mu g are nearly the same (1720 +/- 2650). During the transitional process, the flame heights in mu g were approximately doubled comparing to that in ng, and the flame liftoff heights in mu g were persistently smaller than that in ng. Besides, the transitional flames in mu g appeared to increase soot intensity comparing to those in ng. In the absence of buoyancy intrusion, limits of liftoff and blowout were both extended. In addition, a 2/3 power law correlation between the non-dimensional flame height and the flame Froude number was derived with certain theoretical basis. It was found to agree well with the experimental data for transitional and turbulent lifted flames.
分类号	一类/力学重要期刊
资助项目	National Key Research and Development Program of China[2021YFA0716202] ; National Key Research and Development Program of China[2022YFF0504500]
WOS关键词	STABILIZATION MECHANISM ; OFF HEIGHTS ; COFLOW ; INSTABILITY ; BLOWOUT ; GRAVITY ; LIFTOFF ; EDGE
WOS研究方向	Thermodynamics ; Energy & Fuels ; Engineering
语种	英语
WOS记录号	WOS:001146689000001
资助机构	National Key Research and Development Program of China
其他责任者	Wang, Shuangfeng
内容类型	期刊论文
源URL	[http://dspace.imech.ac.cn/handle/311007/94216]
专题	力学研究所_国家微重力实验室
推荐引用方式 GB/T 7714	Li D,Wen, Yuzhe,Liu, Yu Cheng,et al. On the transition modes and mechanisms for laminar to turbulent lifted jet diffusion flames at normal- and micro-gravity[J]. COMBUSTION AND FLAME,2024,260:10.
APA	李丹,Wen, Yuzhe,Liu, Yu Cheng,&王双峰.(2024).On the transition modes and mechanisms for laminar to turbulent lifted jet diffusion flames at normal- and micro-gravity.COMBUSTION AND FLAME,260,10.
MLA	李丹,et al."On the transition modes and mechanisms for laminar to turbulent lifted jet diffusion flames at normal- and micro-gravity".COMBUSTION AND FLAME 260(2024):10.