空气引射对斯特林发动机火焰特征及燃烧温度的影响

Effect of Air Ejecting on Flame Characteristics and Combustion Temperature of Stirling Engine

为了研究空气引射对斯特林发动机常压燃烧特性的影响,在可视化试验台上进行了不同工况下的燃烧试验,并利用高速摄影机拍摄了燃烧室内的火焰图像,利用热电偶测量了燃烧室内的燃烧温度.结果表明,无空气引射时,燃烧火焰较长,张角较小,波动较大,高温区集中在燃烧室轴线附近;加入适量引射空气,火焰缩短,张角增大,稳定性提高,高温区外扩,位置向喷嘴靠近,燃烧温度升高;过量引射空气使火焰失稳,温度场紊乱,高温区分散,燃烧温度下降.

To study the effect of air ejecting on the combustion characteristics of Stiding engine under atmospheric pressure, combustion experiments under different working conditions were conducted in a visual test bench. In the combustion chamber, flame images were photographed by a high-speed camera and combustion temperature was measured by a series of thermocouples. The results show that, without ejecting air, combustion flame is quite long and has a small divergence angle. It has strong pulsation and high temperature area concentrates round the axis of com- bustion chamber. With a proper amount of ejecting air, combustion flame gets shortened and stable, with its divergence angle increasing significantly, the high-temperature area expands outwards, moving towards the nozzle, and combustion temperature rises. Excess ejecting air results in unstable combustion flame, confused temperature field, dispersed high-temperature area and decreasing combustion temperature.