The experimental studies and numerical simulation were conducted on the effects of the dome fuel distribution ratio on the lean blowout of a model combustor.The experimental results indicate that as the key parameter,the dome fuel distribution ratio,increases from 2.06%to 16.67%,the lean blowout equivalence ratio declines obviously at the beginning,and then the decrease slows down,in addition,the amplitude of the pressure fluctuation in the combustor reduces significantly while the dominant frequency keeps basically constant.In order to analyze the experimental results,the numerical simulation is adopted.The temperature and local equivalence ratio distributions are employed to explain the reason why the lean blowout performance improves with the increase of the dome fuel distribution ratio.
The experimental data of lean blowout fuel/air ratio of a rectangular swirl cup combustor with different inlet temperatures was obtained at atmospheric pressure condition.Numerical simulations both burning and non-burning were performed corresponding to the experimental data at lean blowout.Results indicated that the size of the recirculation region in the primary zone was obviously smaller when burning than non-burning,but the locations of the cores of their recirculation regions were almost the same.The increase of inlet air temperature didn't mean the rise of the temperature of recirculation region core.The location of the maximum temperature in the primary zone was not the same as that one of the core temperature of the recirculation region.Further more,the reasons were analyzed how the lean blowout fuel/air ratio changed with the inlet temperature increasing under the actions of factors both positive and negative to combustion,and this would be helpful to deepen the understanding of the lean blowout process of swirl cup combustor.
The lean blowout experiments of the combustion stability device A (multi-vortexes-dome model combustor) have been carried out at atmospheric pressure. Compared with the device B (single-vortex-dome model combustor), the experimental results show that the device A has a superior lean blowout performance when the combustor reference velocity is within the range from 3.50m/s to 5.59m/s ( while the liner reference velocity is between 3.84 and 6.13m/s), and this superiority will remain stable after the inlet air flow rate reaches a certain value. In order to analyze the phenomena and experimental results, the numerical simulation method is used, and the strain rate and the cold reflux impact are employed to further explain the reason that causes the difference between the two devices' lean blowout characteristics.
Cong ChenYixiang YuanPengfu XieDejun ZhanChao YuWenyu CaoChunqing Tan
