航空替代燃料燃烧特性及碳烟生成数值模拟

Numerical simulation of combustion characteristics and soot generation of aviation alternative fuel

对一种生物燃油(FAME)和传统航油(Jet-A)掺混后的碳烟生成情况进行了研究,燃烧室采用贫油预混预蒸发(lean premixed prevaporized,LPP)低污染燃烧室设计,应用ANSYS fluent软件计算分析了在地面慢车,起飞工况下燃烧室内的冷态流场,热态燃烧和碳烟生成三方面内容。结果表明:FAME燃油的添加有助于降低燃烧室内生成的碳烟数量和质量,但会生成更为精细的碳烟颗粒。随着FAME掺混比的增加,燃烧场温度、碳烟前驱体含量的下降引起了碳烟生成速率的降低,主燃区中心氧化速率的上升使得碳烟初始颗粒的粒径更小,进而最终生成更为精细的碳烟颗粒。FAME燃油的添加能大幅降低慢车工况下的碳烟排放,但对起飞工况下碳烟排放的降低并不显著。

Soot generation of a biofuel(FAME)blended with conventional jet fuel(Jet-A)was investigated,and the combustion chamber was designed as a lean premixed prevaporized(LPP)lowpollution combustion chamber.The three aspects of cold flow field,combustion and soot generation were analyzed by ANSYS fluent software.The results showed that the addition of FAME fuel could help reduce the quantity and quality of soot generated in the combustion chamber,but may generate finer soot particles.The addition of FAME fuel can significantly reduce the soot emission in the idle condition,but the reduction of soot emission in the take-off condition was not significant.