Large eddy simulations show that the penetration of the central jet in a multi-passage lean burn and liquid fueled combustor is dependent on the turbulence levels in the three air-flow passages of the injector. These simulations are performed using an incompressible method where an unsteady boundary condition is applied to the inlets of a truncated domain which only includes the domain downstream of the fuel injector using the recently developed Proper Orthogonal Decomposition Fourier Series method. The fluctuating inlets are built from a combination of compressible URANS data and incompressible LES data. This incompressible method is shown to be consistent with fully compressible simulations whilst requiring only one third of the computing time. Neglecting the turbulence generated in the passages results in the incorrect penetration of the central jet, resulting in a flame transfer function with a similar gain but with a different phase. Furthermore, large scale helical modes, previously detected in non-reacting simulations of a similar burner geometry are seen to be imprinted onto the liquid fuel spray, mixture fraction and heat release fields. This shows that coupling between hydrodynamic instabilities and thermoacoustic instabilities in liquid fueled engines may be more significant than suggested by previous studies of gas fueled engines.

大型涡流模拟表明，中央喷嘴在多通道稀薄燃烧和液体燃料燃烧器中的渗透率取决于喷射器三个气流通道中的湍流度。这些模拟是使用不可压缩的方法执行的，其中使用最近开发的适当正交分解傅里叶级数方法将不稳定的边界条件应用于截断区域的入口，该截断区域仅包括燃料喷射器下游的区域。波动的入口由可压缩的URANS数据和不可压缩的LES数据组合而成。这种不可压缩的方法与完全可压缩的模拟一致，而只需要三分之一的计算时间。忽略通道中产生的湍流会导致中央射流的不正确穿透，从而导致火焰传递函数的增益相似但相位不同。此外，可以看到，先前在类似燃烧器几何形状的非反应模拟中检测到的大规模螺旋模被压印在液体燃料喷雾，混合物分数和放热场上。这表明液体燃料发动机中流体动力不稳定性和热声不稳定性之间的耦合可能比以前的气体燃料发动机研究所建议的更为重要。以前在类似的燃烧器几何形状的非反应性模拟中检测到的现象被认为已印在液体燃料喷雾，混合物分数和放热场上。这表明液体燃料发动机中流体动力不稳定性和热声不稳定性之间的耦合可能比以前的气体燃料发动机研究所建议的更为重要。以前在类似的燃烧器几何形状的非反应性模拟中检测到的现象被认为已印在液体燃料喷雾，混合物分数和放热场上。这表明液体燃料发动机中流体动力不稳定性和热声不稳定性之间的耦合可能比以前的气体燃料发动机研究所建议的更为重要。