Direct numerical simulations of a turbulent premixed stoichiometric methane-oxygen flame were conducted. The chosen combustion pressure was 20 bar, to resemble conditions encountered in modern rocket combustors. The chemical reactions followed finite rate detailed mechanism integrated into the EBI-DNS solver within the OpenFOAM framework. Flame geometry was thoroughly investigated to assess its interaction with the transport of turbulent properties. The resulting flame front was remarkably thin, with high density gradients and moderate Karlovitz and Damköhler numbers. At mid-flame positions, the variable-density transport mechanisms dominated, leading to the generation of both vorticity and turbulence. A reversion of this trend towards the products was observed. For intermediate combustion progress, vorticity transport is essentially a competition between the baroclinic torque and vortex dilatation. The growth of turbulent kinetic energy is strongly correlated to this process. A geometrical analysis reveals that the generation of enstrophy and turbulence is restricted to specific topologies. Convergent and divergent flame propagation promote turbulence creation due to pressure fluctuation gradients through different physical processes. The possibility of modeling turbulence transport based on curvature is discussed along with the inherent challenges.

进行了湍流预混合化学计量甲烷-氧气火焰的直接数值模拟。选择的燃烧压力为 20 bar，类似于现代火箭燃烧器中遇到的条件。化学反应遵循集成到 OpenFOAM 框架内的 EBI-DNS 求解器中的有限速率详细机制。对火焰几何形状进行了彻底研究，以评估其与湍流特性传输的相互作用。由此产生的火焰前锋非常薄，具有高密度梯度和适中的 Karlovitz 和 Damköhler 数。在中火位置，可变密度传输机制占主导地位，导致产生涡度和湍流。观察到这种趋势向产品的逆转。对于中间燃烧进程，涡量输运本质上是斜压力矩和涡量膨胀之间的竞争。湍动能的增长与该过程密切相关。几何分析表明，熵和湍流的产生仅限于特定的拓扑结构。由于压力波动梯度通过不同的物理过程，会聚和发散的火焰传播促进了湍流的产生。讨论了基于曲率模拟湍流传输的可能性以及固有的挑战。由于压力波动梯度通过不同的物理过程，会聚和发散的火焰传播促进了湍流的产生。讨论了基于曲率模拟湍流传输的可能性以及固有的挑战。由于压力波动梯度通过不同的物理过程，会聚和发散的火焰传播促进了湍流的产生。讨论了基于曲率模拟湍流传输的可能性以及固有的挑战。