摘要
对H_2/空气预混气在水力直径均为1.0 mm的方管和圆管内的燃烧特性进行三维数值模拟。研究结果表明:方管的可燃浓度范围和速度范围均比圆管的要宽。定量分析表明这主要有3个方面的原因:1)方管的散热损失比例略比圆管的小;2)方管的截面周长比圆管的更大,火焰根部更长,尤其是4个角落存在速度极低的稳燃区;3)方管内火焰顶部的应变率相对于圆管的更小,火焰受到的拉伸效应更弱。这3方面的因素综合起来,使得方管具有更强的稳燃能力。
Combustion characteristics of H2/air flames in square and circular micro tubes with a hydraulic diameter of 1.0 mm were numerically investigated.The results show that the combustible ranges of both equivalent ratio and inlet velocity of the square tube are wider than that of the circular tube.Numerical analysis reveals that there are three reasons for these differences in flame stabilization ability.Firstly,the heat loss ratio of square tube is slightly less than that of the circular tube.Secondly,the square tube has a larger circumference and a very low velocity zone in the four corners.Thirdly,the strain rate at the flame tip in the square tube is smaller and thus the flame suffers a weaker stretch effect.
作者
范爱武
袁自力
FAN Aiwu;YUAN Zili(School of Energy and Power Engineering,Huazhong University of Science and Technology,Wuhan 430074,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2019年第1期214-219,共6页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(51576084)~~
关键词
微尺度燃烧
截面形状
燃烧极限
散热损失
边界层
拉伸效应
micro combustion
cross-section geometry
combustible limits
heat loss
boundary layer
stretch effect
