Title: Experiments in a novel quasi-1D diffusion flame with variable bulk flow Show Chinese title

Title: 在新型准一维可变主体流动扩散火焰中的实验

Abstract: The novel species injector of a recently developed research burner, consisting of an array of hypodermic needles, which allows to produce quasi one-dimensional unstrained diffusion flames has been improved. It is used in a new symmetric design with fuel and oxidizer injected through needle arrays which allows to independently choose both the magnitude and direction of the bulk flow through the flame. A simplified theoretical model for the flame position with variable bulk flow is presented which accounts for the transport properties of both reactants. The model results are compared to experiments with a CO2-diluted H2-O2 flame and variable bulk flow. The mixture composition throughout the burning chamber is monitored by mass spectrometry. The resulting concentration profiles are also compared to the simplified theory and demonstrate that the new burner configuration produces a good approximation of the 1-D chambered diffusion flame, which has been used extensively for the stability analysis of diffusion flames. Hence, the new research burner opens up new possibilities for the experimental validation of theoretical models developed in the idealized unstrained 1-D chambered flame configuration, in particular models concerning the effect of bulk flow magnitude and direction on flame stability. Some preliminary results are presented on the effect of bulk flow direction on the thermal-diffusive cellular flame instability. Show Chinese abstract

Abstract: 新型物种注入器是最近开发的一种研究燃烧器的改进部分，该注入器由一组皮下针组成，能够产生准一维无应变扩散火焰。 它被用于一种新的对称设计中，燃料和氧化剂通过针阵列注入，这允许独立选择通过火焰的整体流动的大小和方向。 提出了一种简化的理论模型来描述具有可变整体流动的火焰位置，该模型考虑了两种反应物的传输特性。 模型结果与CO2稀释的H2-O2火焰及可变整体流动的实验进行了比较。 燃烧室内的混合物组成通过质谱法监测。 所得浓度分布也与简化理论进行了比较，并表明新燃烧器配置产生的是一维室状扩散火焰的良好近似，这种火焰已被广泛用于扩散火焰稳定性分析。 因此，新的研究燃烧器为理想化无应变一维室状火焰配置中发展出的理论模型的实验验证开辟了新的可能性，特别是关于整体流动大小和方向对火焰稳定性影响的模型。 一些初步结果显示了整体流动方向对热扩散细胞状火焰不稳定性的效应。