In accident scenarios originating from weak ignition, flame acceleration preconditions the fresh gas ahead of the flame front and provides the necessary conditions for deflagration-to-detonation transition to occur. Strong shear layers, which form at the rear edge of obstacles in the accelerated flow of fast flames, isolate fresh gas pockets. Vortices in the intense shear layer have the potential to locally quench the flame, limiting the integral heat release and delaying the onset of detonation.

This study investigates the potential of local turbulent quenching in H${}_2$-CO-air mixtures. First, the presence of locally reduced heat release is visualized in highly resolved simulations for H${}_2$-air and H${}_2$-CO-air flames. Efficient simulation methods are of great importance for risk analysis studies. In connection with the results from highly resolved simulations this justifies a more detailed look at RANS-based combustion models for said flames. Thus, three different treatments of turbulent quenching are investigated, in which the geometrical configuration (blockage ratio and obstacle spacing) and the geometry size is varied.

The results indicate that quenching does not need to be considered in RANS-based combustion models for H${}_2$-CO-air flames in explosion scenarios. But since quenching does eventually occur at very high turbulence intensities, the authors suggest limiting the flame turbulence interaction to flame stretch values obtained from 1D counter-flow flame simulations with detailed chemistry.

在源自弱点火的事故场景中，火焰加速会在火焰前沿之前对新鲜气体进行预处理，并为从爆燃到爆燃过渡的发生提供必要的条件。在快速火焰加速流动的障碍物后缘形成的强剪切层隔离了新鲜的气穴。强剪切层中的涡旋有可能局部熄灭火焰，从而限制了整体放热并延迟了爆炸的开始。

这项研究调查了H中局部湍流淬灭的潜力${}_{\mathrm{2个}}$-CO-空气混合物。首先，在高度解析的H模拟中可视化了局部减少的放热现象${}_{\mathrm{2个}}$-空气和H${}_{\mathrm{2个}}$-CO-空气火焰。高效的模拟方法对于风险分析研究非常重要。结合高度解析的模拟结果，可以证明对上述火焰基于RANS的燃烧模型进行了更详细的研究。因此，研究了湍流淬火的三种不同处理方法，其中改变了几何构型（阻挡比和障碍物间距）和几何尺寸。

结果表明，在基于RANS的H燃烧模型中无需考虑淬火${}_{\mathrm{2个}}$-爆炸场景中的CO-空气火焰。但是由于淬火最终确实会在非常高的湍流强度下发生，因此作者建议将火焰湍流的相互作用限制在通过详细化学反应从一维逆流火焰模拟获得的火焰拉伸值。