模型燃烧室低频不稳定燃烧的初步探讨

对模型燃烧室在贫油预混条件下产生的燃烧不稳定性的特性进行了初步研究。实验研究了当量比、预混气的喷射速度和燃烧室出口面积对不稳定燃烧的频率和幅值的影响。实验结果表明:在很宽的油气比和速度范围内,出现了燃烧不稳定现象,但振荡的主频集中在200～235Hz之间;随着预混气喷射速度的增加,燃烧不稳定发生的频率和幅值都增加;随着燃烧室出口面积的减小,不稳定燃烧发生的振荡幅值增加而频率却减小,表明不稳定模态发生了变化。 

A Preliminary Investigation of Low-Frequency Combustion Instability in a Model Combustor

A preliminary investigation of low frequency combustion instability has been conducted in an atmospheric combustion facility.The result indicates that at higher equivalence ratios,typically above 06,the combustion process becomes highly unstable,exhibiting large-amplitude pressure oscillations at some frequencies between 200 Hz and 235 Hz.The frequency and amplitude of instability grow with increasing premixed gas injection velocity.The result also shows that the instability mode changes when the exit area of the combustor decreases to some critical value.