喷嘴损伤对环形回流燃烧室性能的影响

Effect of nozzle damage on performance of annular backflow combustor

利用Fluent商用软件对模型环形回流燃烧室三维两相喷雾燃烧流场进行了数值模拟,研究了喷嘴损伤引起雾化效果变化对燃烧室性能的影响,采用可实现的k-ε模型模拟湍流黏性、离散相模型(DPM)通过添加UDF(user defined function)程序追踪燃油运动轨迹、正庚烷作替代燃料及层流小火焰模型.计算结果表明:采用的数值模拟方法可以预估实际燃烧室燃烧流场以及喷嘴损伤对其性能的影响,雾化性能变化导致燃烧室出口温度分布不均匀度升高,品质降低,并导致燃烧室燃烧效率降低;当燃油流量降低约19%时,燃烧室性能已不符合运行要求.

The effects of different atomization performance caused by nozzle damage on the annular backflow combustor performance were studied by using Fluent software.Threedimensional two-phase spray combustion flow fields in a model annular backflow combustor were numerically simulated using realizable k-ε model,DPM （discrete phase model） with UDF （user defined function） subroutines tracking fuel trajectory,n-heptane as surrogate fuel and laminar flamelet model.The results reveal that the numerical method is reasonable to predict combustion flow of annular backflow combustor.The outlet temperature non-uniformity deterirated with the atomization performance＆#39;s change caused by nozzle damage.And the combustion efficiency also decreased.When the fuel flow rate was reduced by 19%,the performance of the combustor was not conformity with the operational requirements.