协流温度对喷射起升火焰燃烧稳定性的影响

Effect of Coflow Temperature on Combustion Stabilization of Jet Flames

摘要:

利用活化热氛围燃烧器提供的稳定热氛围场分析了中央喷射液体燃料的起升火焰的基部高度变化，研究不同协流温度对起升火焰燃烧稳定性的影响，研究表明，协流热氛围中液体燃料喷射起升火焰基部的跳变是自燃现象作用的结果；不同协流温度时中央喷射起升火焰的稳定机理不同；存在一个火焰基部稳定的临界温度，低于此温度时起升火焰的稳定受控于燃料的自燃现象，而高于此温度时起升高度的稳定受火焰传播主导；火焰跳变频率及跳变长度与协流温度有关；温度越低则火焰基部跳变越频繁；跳变长度随温度的增加而减小.

Abstract:

The effect of coflow temperature on stabilization of lifted turbulent jet flames of liquid fuels in controllable active thermo atmosphere（CATA）was investigated through analyzing the flame base heights fluctuation. The test results show that a flame base jump is an auto ignition phenomenon the upward flame base. The stabilization mechanism of the lifted flame varies with co flow temperature and 1 074 K is considered as a critical point. The lifted flame is controlled by the auto ignition of fuel upward flame base bet when the temperature is below 1 074K, and the flame stabilization is controlled by the flame spread speed when it is over 1 074 K. Flame base jump frequency and length are related to the co flow temperature. As the co flow temperature increases, the flame base jumps less frequently and the jump lengths are shortened.