燃烧室尺寸优化下的航空发动机排放性能研究

航空活塞发动机的排放问题始终备受关注,其燃烧室的尺寸对发动机排放性能具有一定的影响,以某航空活塞发动机为研究对象,从燃烧喷雾模型出发,利用Fire建立其燃烧室模型,在现有燃烧室几何参数的基础上提出改进,利用新的方案进行仿真分析,在某一瞬态下对比新旧方案的氮氧化合物和碳烟排放。结果表明:新的燃烧室结构下发动机氮氧化合物排放降低23%,碳烟排放降低2.8%,总体排放下降;将修正后的燃烧室装配到发动机上,经实验台架测试后,发动机功率和扭矩不变,排放物明显降低,该设计方案可行。

Simulation of Aero Diesel Engine Emission Based on Combustion Chamber Size Optimization

The emission of engines has been a focused issue. With a piston engine as the object of study, Fire was used to establish a type of engine combustion chamber model from the perspective of combustion spray model; changes based on geometric parameters of existing combustion chamber were proposed; and simulation analysis was carried out under the new program; the nitrogen and oxygen compounds and carbon emissions between the old and new program were compared in a transient state. The results show that the emission of nitrogen oxides under the new combustion chamber structure is reduced by 23%, the carbon emission is reduced by 2.8%, and the overall emission is decreased. After installing the modified combustion chamber into the engine and maintaining the engine power and torque unchanged, a reduction in emission is clearly shown, which proved the design program is feasible.