狭长圆柱型燃烧室内的燃烧不稳定性

Characteristics of Combustion Instability in a Narrow Combustion Cylinder

研究了狭长圆柱型燃烧室内的喷雾火焰燃烧的不稳定性.为了更清楚地了解火焰的构造,首先测量了火焰的温度场.在较大的一次风和二次风变化范围内,测量了压力的振荡特性,得出其均方根值图.结果表明,火焰的稳定是由回流区完成的,在较小的一次风燃料当量比和中等的二次风量时,振荡强度达到100Pa左右.其频率为200～230Hz,与空气/燃料比值关系不大.分析还表明燃烧室中的振荡是轴向驻波振荡.

The characteristics of thermal instability in a confined combustion cylinder with liquid spray flame were investigated. The temperature distribution of the flame was obtained by thermocouple to get the flame structure. Rootmeansquare (RMS) pressure oscillation contours within the relatively wide ranges of primary and secondary air flow rates were obtained. The results show that the spray flame is stabilized by the recirculation zones. The maximum RMS pressure oscillation in this condition is about 100 Pa. The frequencies of instability are in the range of 200—230 Hz, which do not depend on the air/fuel ratio very much. This instability is believed to be an axial standing wave oscillation.