航空发动机环形燃烧室燃烧与排放物生成的反应动力学研究

This project focus on the reaction kinetic of combustion process and emissions formation in the aunular combustor of an aero-engine, which is a critical technology problem. By applying theory analysis, experimental study and numerical simulation, the characteristics of ignition and combustion of RP-3 kerosene and it's surrogate fuel were studied, and the detailed and reduced reaction mechanisms of this surrogate fuel were built. Combining this reduced reaction mechanism of this surrogate fuel with CFD computational model, the combustion process and emissions formation in the aunular combustor of an aero-engine were kinetic simulated, the effects of the structures of the hydrocyclone and nozzle, distributions of inlet air, and fuel/air equivalence ratio on the flow field, stability of combustion, combustion characteristics, formations of the intermediate species and main emissions were analyzed, and the influence mechanism between the characteristics of fluid and reaction kinetic was illustrated. Furthermore, the cold and thermal states experiments of the aunular combustor of this aero-engine were done. The characteristics of the flow field in the combustion chamber and temperature field, velocity field, pressure field and emissions concentration fields of the combustion chamber outlet were gained and compared with the results of simulation. This research will present original results and provide the scientific basis for improving combustion stability and performance and reducing emissions of aero-engine.

项目围绕航空发动机环形燃烧室燃烧过程与排放物生成的反应动力学特性这一关键科技问题，采用理论分析、实验研究和数值计算相结合的方法，深入研究RP-3航空煤油及其替代燃料的着火与燃烧特性，形成该替代燃料的化学反应详细机理与简化机理；耦合该替代燃料的简化机理与CFD计算模型，对某型航空发动机环形燃烧室的燃烧过程与排放物生成进行反应动力学数值计算，分析燃烧室的旋流器结构、燃油喷嘴结构、空气进气分配、燃空当量比等对燃烧室内湍流流场、燃烧稳定性、燃烧特性、中间组分与主要排放物生成规律的影响，阐明流场特性与反应动力学特性之间的相互影响机制；对该型号航空发动机环形燃烧室进行冷态和热态实验，获得燃烧室内的流场特性与燃烧室出口温度场、速度场、压力场和排放物浓度场的分布情况，并与数值计算结果进行对比分析。该项研究必将提出原创性成果，为进一步采取措施提高航空发动机燃烧稳定性、燃烧性能、降低污染物排放提供理论依据。

项目围绕航空发动机环形燃烧室燃烧过程与排放物生成的反应动力学特性这一关键科技问题，深入研究了RP-3航空煤油及其替代燃料的着火与燃烧特性，构建了替代燃料的燃烧反应详细机理与简化机理；耦合替代燃料的简化机理与CFD计算模型，对某型航空发动机环形燃烧室的燃烧过程与排放物生成进行了反应动力学数值计算。研究结果表明，在不同压力与当量比下，RP-3航空煤油的着火延迟时间的对数与着火温度的倒数呈直线关系，同时，随着着火温度与压力的升高以及混合气化学当量比的降低，着火延迟时间逐渐缩短。随着初始温度的升高或初始压力的降低，RP-3航空煤油的层流燃烧速度逐渐升高；随着当量比由0.6升高至1.6，层流燃烧速度呈现先增加后降低的趋势，当当量比为1.2时，层流燃烧速度最大。随着初始压力或当量比的降低，马克斯坦长度逐渐增大，火焰稳定性增强；初始温度对马克斯坦长度的影响不明显，当当量比为0.9-1.1时，随着初始温度的升高，马克斯坦长度逐渐减小，但当当量比为1.2-1.5时，马克斯坦长度则有所增大。提出了RP-3航空煤油单组份、双组份以及三组份替代燃料，构建了相应替代燃料的燃烧反应详细与简化机理，并完成了试验验证。与采用C12H23为燃料的单步反应机理相比，采用正癸烷为替代燃料的简化反应机理计算得到的某型航空发动机环形燃烧室内温度场分布更符合实际，其出口平均温度亦更为接近燃烧室出口设计温度；同时，能更为详细了解燃料低温裂解过程及裂解产物、中间产物及主要排放物的生成规律。项目的研究成果为进一步采取措施提高航空发动机燃烧稳定性、燃烧性能、降低污染物排放提供了理论依据。