Stability of Gas Diffusion Flame in Laterally Confined Space  

作　　者：WANG Xiuzhen ZHU Feng WANG Shuangfeng 

机构地区：[1]Key Laboratory of Microgravity,Institute of Mechanics,Chinese Academy of Sciences,Beijing 100190,China [2]School of Engineering Science,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Journal of Thermal Science》2024年第6期2437-2449,共13页热科学学报（英文版）

基　　金：supported by the Space Application System of China Manned Space Program,and the National Key Research and Development Program of China under grant number 2022YFF0504500.

摘　　要：Lateral-confined coaxial jet diffusion flame is common in micro thrusters,and the specific impulse is mainly obtained through thermodynamic calculations with an assumption of fuel combustion with an equivalence ratio,regardless of the stability of the combustion process.However,the flame behavior plays an important impact on the performance of a micro thruster through the varied combustion efficiency.The stability of confined coaxial jet diffusion flames with air coflow was studied by experiments and numerical simulation.Methane,hydrogen,and propane were used as fuels.Flame attachment,liftoff,blowout(extinction limits of lifted flame),and blowoff(extinction limits of attached flame) behaviors with the effect of confinement ratios and fuel properties were focused on.Among the range of the jet flow velocity in this research,the hydrogen flame is always attached to the jet exit,the flame tip goes from closed to open as the jet velocity increases,while the flame transitions from attachment to liftoff in the case of CH_(4) and C_(3)H_(8) .Further,in a narrow confined space,the attached flame for both CH4 and C_(3)H_(8) undergoes liftoff followed by blowout.However,in a space with a high confinement ratio,the CH4 flame transitions directly from attachment to blowoff.The critical modified Craya-Curtet number,which is used to predict the onset of the recirculation,is determined through simulation and experiment,and the number is about 1.77.This work provides valuable data on flame stability inside a confined space and gives insights into the design of a thruster.

关 键 词：jet diffusion flame Craya-Curtet number flame stability confined space 

分 类 号：V430[航空宇航科学与技术—航空宇航推进理论与工程]