氢燃料燃烧室旋流微扩散方案设计及数值仿真分析

Design and numerical simulation analysis of hydrogen combustion chamber rotation micro diffusion scheme

为实现航空发动机零碳排放,采用氢燃料对燃油发动机燃烧室进行修改设计及仿真分析。为了不影响涡轮对燃烧室出口温度场的要求,燃烧室改氢设计基于相似温度场和火焰筒空气流量分配基本不变的原则,以及最小化修改设计原则,仅对头部(含喷嘴)开展全新设计,而对机匣仅进行适应性修改设计。数值仿真分析发现:改氢燃烧室方案的流场与燃油方案的不同,其流场存在角回流区和主回流区,与常规中心分级贫油预混预蒸发燃烧室的流场相似,高温区集中在主回流区和剪切层内;与燃油方案相比,改氢方案的出口径向温度分布曲线均在沿叶高2/3附近,出口温度场更加均匀,出口温度分布系数约为0.154,燃烧效率更高,表明燃烧室改氢设计对涡轮影响较小。

To achieve zero carbon emissions from aviation engines,hydrogen fuel was used to modify the design,and simulation analysis of a certain type of fuel engine combustor was carried out.In order not to affect the requirements of the turbine for the temperature field at the outlet of the combustor,the hydrogen conversion design of the combustor was based on the principle of similar temperature fields and unchanged air flow distribution in the flame tube.At the same time,based on the principle of minimizing modification design,only the dome(including the nozzle)was newly designed,and the casing was adaptively modified.Through numerical simulation analysis,it has been found that the flow field of the hydrogen conversion scheme is different from that of the fuel scheme,with the presence of angular recirculation zone and main recirculation zone,and the high temperature zone concentrated in the main recirculation zone and shear layer.Compared with the temperature field of the fuel scheme,it has been found that the radial temperature distribution curve of the outlet is around 2/3 of the blade height,and the outlet temperature field is more uniform.The outlet temperature distribution factor is around 0.154 with higher combustion efficiency,indicating that the improved design has little impact on the turbine.