钝体后预混火焰稳定机理与钝体尺寸间关系的研究

Study on Stabilization Mechanism of Premixed Flame

关键词:  火焰根部  V型钝体尺寸  贫油预混燃烧

Key words:  Flamebases  V-gutter size  Lean premixed combustion

摘要:

为了进一步理解火焰稳定的详细机理，采用钝体作为火焰稳定机理的研究模型，详细分析了火焰根部流场特性对于火焰稳定的影响。研究了二维通道中不同尺寸V型钝体在不同进口速度下的反应流场，分析了预混煤油火焰根部特性。进口煤油和空气的当量比为Φ=0.6，进口温度300K，环境压力0.1MPa。结果显示在钝体分别为小尺寸、中间尺寸和大尺寸时，钝体后火焰根部特征、回流区特征和火焰根部位置随进口速度变化的规律都各不相同。当D=1mm钝体尺寸较小时，速度从0.4m/s增加到0.48m/s，一个火焰根部向下游移动4.5mm；当D=8mm钝体为中间尺寸时，来流速度从1m/s增加到5m/s，两个火焰根部首先向下游移动7mm，再向上游移动3.7mm；当D=32mm钝体尺寸较大时，来流速度从5m/s增加到25m/s，两个火焰根部均向上游移动2mm。

Abstract:

In order to understand the detailed mechanism of flame stabilization，the effects of the characteristics of the flamebases on the flame stabilization are investigated. Two dimensional premixed flames after the V-gutters for different sizes in 2-D passages under different inlet velocities are performed，and the flame bases are investigated. The inlet mixture of kerosene and air is at Φ=0.6，300K and 0.1MPa. The results show that the flamebases characteristics，recirculation zones characteristics and the movements of flamebases location with different inlet velocities are not the same for small ，middle and large size V-gutters. When the V-gutter size is small，such as D=1mm，as the inlet velocity increases from 0.4m/s to 0.48m/s，the movement of one flamebase is 4.5mm downstream. When V-gutter size is medium such as D=8mm，as the inlet velocity increases from 1m/s to 5m/s，the movement of the flamebase is first 7mm downstream and then 3.7mm upstream. When V-gutter size is large，such as D=32mm，as the inlet velocity increases from 5m/s to 25m/s，the movement of each flamebase is 2mm upstream.