A physics-based, low-order ignition model is used to assess the ignition performance of a kerosene-fueled gas-turbine combustor under high-altitude relight conditions. The ignition model used in this study is based on the motion of virtual flame particles and their extinction according to a Karlovitz number criterion, and a stochastic procedure is used to account for the effects of spray polydispersity on the flame’s extinction behavior. The effects of large droplets arising from poor fuel atomization at sub-idle conditions are then investigated in the context of the model parameters and the combustor’s ignition behavior. For that, a Reynolds-averaged Navier-Stokes simulation of the cold flow in the combustor was performed and used as an input for the ignition model. Ignition was possible with a Sauter mean diameter (SMD) of 50 μm, and was enhanced by increasing the spark volume. Although doubling the spark volume at larger SMDs (75 and 100 μm) resulted in the suppression of short-mode failure events, ignition was not achieved due to a reduction of the effective flammable volume in the combustor. Overall, a lower ignition probability is obtained when using the stochastic procedure for the spray, which is to be expected due to the additional detrimental effects associated with poor spray atomisation and high polydispersity.

基于物理学的低阶点火模型用于评估以煤油为燃料的燃气轮机燃烧器在高海拔重新点燃条件下的点火性能。本研究中使用的点火模型基于虚拟火焰粒子的运动及其根据卡洛维茨数准则的熄灭，并使用随机程序来解释喷雾多分散性对火焰熄灭行为的影响。然后在模型参数和燃烧器点火行为的背景下研究在亚怠速条件下燃料雾化不良引起的大液滴的影响。为此，对燃烧器中的冷流进行了雷诺平均 Navier-Stokes 模拟，并将其用作点火模型的输入。使用 50 μm 的 Sauter 平均直径 (SMD) 可以点火，并通过增加火花体积得到增强。尽管在较大的 SMD（75 和 100 μm）下将火花体积加倍可以抑制短模式故障事件，但由于燃烧器中有效可燃体积的减少，点火并未实现。总体而言，当对喷雾使用随机程序时，获得较低的点燃概率，这是可以预料的，这是由于与喷雾雾化差和多分散性高相关的额外不利影响。